Tag Archive for: immune function



Spring’s new growth and beautiful flowers brighten the world after long months of colder, wetter weather. But with that flourishing flora comes something else—pollen and seasonal allergies.

For many people, they can feel the moment the world around them shifts from winter into spring. Their eyes become watery and itchy. Their nose runs or stuffs up. Sneezing becomes just as common as laughing. When these symptoms pop up, it’s time to reach for the allergy medication so you can get through the day in one piece. But have you ever been told to reach for local honey for seasonal allergies instead?

Honey, particularly products harvested locally, is often suggested as a natural way to help you deal with allergies when spring comes around.

But does honey actually help with seasonal allergies? To answer that question and separate myth from fact, let’s look at how allergies work, how honey is made, and where the two might intersect.

What are Seasonal Allergies?

First, you have to understand what happens in your body when spring comes around. You can go in depth about seasonal allergies with this helpful story. But here’s a brief overview:

Imagine your body is a thriving 24/7 office building. All the busy workers inside the building are your cells. Some cells are in the department responsible for moving your muscles. Others are in departments that make sure you have the energy to go about your day.

The work your cells do is very important—it keeps you alive. But there are many threats inside and outside your body that can cause problems.

In a building, someone could break in, or internal issues, like a flood from a burst pipe, can pop up. In your body, you can cut your skin or breathe in foreign particles that can cause a variety of problems.

To protect you from potential threats, you have a natural security system—your immune system. This is like the security and on-site first responders in the office building. These immune cells are always on patrol. They keep an eye out for anything that they think might hurt you. When they find a potential threat, they mobilize quickly to contain and remove it.

However, they occasionally come across particles that are relatively harmless—like pollen from blooming trees and flowers—and your security system overreacts. Your immune cells trigger alarms throughout the entire building of your body, temporarily disrupting everyone’s work with sneezing, watery eyes, and a runny nose.

When the threat is taken care of, security posts pictures of the intruder so your cells can remember what it looks like for next time. And that’s why your seasonal allergies happen at predicable times.

Using Immune Memory to Your Allergy Advantage

When your immune system comes across pollen again, your immune cells recognize the pollen from all the pictures it took and posted up the last time they encountered one another. That memory allows your immune system to respond faster and better every time it encounters the familiar threat, because it learned how to best deal with it last time.

This system works great for threats like viruses or bacteria. These threats don’t usually happen every day, so the immune system doesn’t become desensitized to seeing the same problem repeatedly.

But imagine if the same problem kept happening every day. Most likely, the immune cells would stop responding as aggressively. Eventually, they might even learn to just live with it like a busted ceiling tile in the break room or a tiny leak in the roof whenever it rains.

When this conditioning is done intentionally, it’s called immunotherapy. These techniques can be used to help train your body to grow comfortable with having particles like pollen around, so your immune system learns to live with its presence and ignore it.

This is how allergy shots work. By giving you a concentrated dose of particle pieces that you’re allergic to every few weeks or months, you can train your immune system to desensitize itself to the presence of that allergy-causing substance.

How the Properties of Honey Relate to Seasonal Allergies

Now that you have the gist of seasonal allergies, let’s look at the next piece of this puzzle—honey.

Honeybees produce the sticky substance by gathering a liquid called nectar that is produced by flowering plants. The bees store nectar in an extra stomach in order to carry it back to their hive.

While the nectar is hanging out in the stomach, it mixes with other items the bee has eaten. This changes the chemical makeup of the nectar so it’ll last longer, like preserving fruits to make jam that can last longer on your shelf or in your fridge.

Once the bees return to their hives, they pass the preserved nectar from their stomach to another bee, who stores it in their extra stomach to pass on to another bee. The nectar passes from bee to bee until it reaches its final destination—a honeycomb.

After the last bee in the chain coughs up the nectar into the honeycomb, the bees in the hive use their wings to help any extra liquid in the nectar quickly evaporate so the honeycomb can be sealed up for storage. Now the bees have a sweet food storage to dig into during winter months, and humans have a sugary addition to their diet that may also help with seasonal allergies.

Now it’s time to circle back to the theory of using honey for seasonal allergies works. Basically, it goes like this:

When bees are gathering nectar from flowers they pick up pollen, which may end up mixed into the honey. So in theory, if you eat a lot of this pollen-containing honey, your immune system will start acclimating to seeing the pollen in your body. Once your immune system sees this once-alarming substance so many times, your immune cells stop responding to it.

With no immune cells sounding an alarm, your seasonal allergy symptoms aren’t triggered, and you can breathe easier.

But Does Local Honey Actually Help with Seasonal Allergies?

First, the bad news. There’s no guarantee the honey you eat has any pollen in it. Additionally, there are a lot of plants out there that produce pollen, and not all of them have flowers that are the preferred targets of honeybees.

In fact, honeybees usually prefer plants that aren’t commonly considered the main sources of pollen that commonly triggers seasonal allergies.

Other bad news: if someone has recommended you eat honey for allergies, they probably have told you that it needs to be local honey. That’s because different areas have different plants. If you eat honey with pollen from Alaska and you live in Arizona, the pollen in the honey will be very different from the particles hanging in the air around your house.

In many cases, local honey is also sold relatively unprocessed. That means there might be bee parts, bee venom, or bacteria. If you’re allergic to bees themselves, eating this type of honey might cause its own allergic reaction and make your allergy problem even worse.

There is Some Good News About Honey

Don’t toss your honey out just yet. Eating honey has many other benefits that can help you optimize your experience during the season. For instance, it can help soothe a cough, especially when used to sweeten tea instead of using sugar. Just don’t give it to kids younger than a year old, because it can cause a life-threatening illness called botulism.

There also might be some potential of using honey at high doses alongside normal allergy treatments to help manage the symptoms of seasonal allergies. There are few studies on this topic, and they often provide mixed results. But one small study found that large doses of unprocessed honey seemed to help sufferers of seasonal allergies deal with their symptoms, at least for a little while.

Of course, you’d probably need to eat a lot of honey. In that particular study, participants ate at least 50-60 grams (about two and a half tablespoons) of unprocessed raw honey every day for a couple of months.

What’s the Final Verdict?

With all that said, it’s time to answer the question—does eating honey help with seasonal allergies?

Well, it can certainly help you manage symptoms like a cough. And the theory about pollen in the honey makes sense. But, for now, it’s best to reach for the allergy medications and limit your time outdoors until pollen season has ended for the year.

pandemic vs epidemic

pandemic vs epidemic

COVID-19 has left its mark on all our lives—including our language. Let’s take a moment to think back on life in 2019. Back before the toilet paper shortages and society’s massive shift to working from home, how often did you use words like “epidemic” and “pandemic”?

Unless you work in the medical field or were talking about a movie, you probably didn’t think much about words like that. Now, it’s difficult for most people to go even a few days without hearing someone use one or both of those words on the news or in normal conversation. Everyone has just accepted words like “pandemic” and “epidemic” into daily lingo—but what does it mean? And what’s this new word “endemic” that other people have been using?

To get to the bottom of that question, let’s dive into the world of those who study diseases for a living. And along the way, take a look at the answer to the question on many people’s minds—will the pandemic ever end?

Epidemiology is the Word: The Study of Diseases

First, let’s look at the branch of medicine that sets the rules for what defines a pandemic vs endemic vs epidemic. This responsibility falls on epidemiologists—the scientists you’ve probably heard from the most during COVID-19. That’s because epidemiology is the study of the causes, risk factors, and spread of problems that threaten public health within specific populations.

Epidemiologists identify these potential threats and investigate them just like a detective investigates a crime. Their goal is to study the problem, figure out how it started, who’s most at risk of being affected, and determine the best course of action. They also look at ways to prevent the problem from getting worse.

Like any science, epidemiologists’ work is ongoing as they learn more about the threat, and the threat itself evolves and changes. Whenever you heard about the six-foot rule of social distancing or learned about when you should wear a mask, you were seeing the work of these scientists.

What’s an Epidemic?

When you first heard of COVID-19 in the end of 2019, it was described as an unknown type of pneumonia spreading quickly through millions of people in the city of Wuhan, China. Eventually, that virus spread past the city’s borders and throughout the rest of the country—until finally crossing oceans and borders.

In those first few months, the COVID-19 virus outbreak was an epidemic—a disease that had rapidly and unexpectedly spread through a large number of people within a specific population or region. There have been many other epidemics throughout the history of the world, including the smallpox, measles, and polio.

When an Epidemic Becomes a Pandemic

In some cases, an epidemic disease can move on to become a pandemic—an epidemic that has rapidly spread across borders into other countries and continents. The prefix pan- in pandemic means “all,” just like Pan American means “all the Americas.”

Not all epidemics move on to the next stage to become a pandemic. Some epidemics flare up and die out quickly before they can make the jump and go global. However, once the disease spread picks up and cases start to skyrocket as it spreads out from its country of origin, an epidemic arrives at its next definition and becomes a pandemic.

The COVID-19 epidemic officially became the COVID-19 pandemic in March 2020 when it was declared a pandemic by the World Health Organization (WHO). By then, COVID-19 had spread to more than 100 countries. Before the COVID-19 pandemic, the last pandemic was the H1N1 influenza pandemic in 2009.

When a Pandemic Becomes Endemic

So what’s the next step after a pandemic? In some cases, like polio, the widespread use of the polio vaccine in the United States got rid of the disease to the point that there hasn’t been a polio case in the country since 1979.

In other cases, the disease slows down, and fewer and fewer people get sick until the virus isn’t actively circulating through the population. Occasionally, there will be outbreaks that are quickly identified and monitored to prevent them from spreading. This is the case with measles. An outbreak happens when there are new disease cases in a population or region where the disease normally isn’t.

Then there are the diseases that slow down but don’t ever truly go away. They continue circulating within a specific population or region. Enough people within the population have immunity either from getting the disease or from vaccines, making it more difficult for the disease to spread as fast as it once did.

At some point in this process, the pandemic becomes an endemic—a disease that’s in constant circulation within a specific population or region. To remember the difference between epidemic and endemic, think of the “end-” in endemic. It makes an endemic a potential end to a pandemic.

Malaria is an example of an endemic. It’s mostly found in tropical countries and rarely spreads outside that confined range (and when it does, that’s classified as an outbreak).

Picturing the Pandemic End: The COVID-19 Endemic

Eventually, COVID-19 is expected to become an endemic disease. It won’t ever truly be gone, but as more and more people acquire some form of immunity, the severity and number of cases will decrease. Most scientists think COVID-19 will eventually become like the flu, where cases are worse during some seasons but the disease itself is always present.

So will there ever be an end to the COVID-19 pandemic? The answer to that is—yes. Eventually. But the disease itself won’t go away completely, and only time will tell what the COVID-19 endemic future will look like.

The old adage says, “an apple a day, keeps the doctor away.” But there are other immune supporting foods along the aisles of the grocery store. Immunity nutrition is a popular target of today’s diet trends. And while a variety of wholesome foods are needed to create a balanced diet, some are particularly good sources of immunity nutrients.

Foods that support your body’s immune system are nutrient dense. That means they’re packed with vitamins, minerals, phytonutrients, and other helpful nutrients. Beta-glucans, vitamin C, B vitamins, and zinc are some of the most important immunity nutrients.

They all work to protect your health. These nutrients support the function of immune system cells—like neutrophils, macrophages, and natural killer cells. By supporting your natural defenses, immunity nutrition can help maintain your health.

It is important to get these nutrients in your daily meals. And the good news is each comes in a healthy, delicious package. Whether it’s red pepper, kiwi, chickpeas, or cashews, make sure you get immune supporting foods each time you go to the grocery store.

Fungi, Whole Grains, and Dairy: Beta Glucans

Mushrooms have famously been linked to immune health. But more foods than mushrooms contain beta-glucans—the nutrients responsible for mushrooms’ immune support. Beta-glucans are sugars found in the cell walls of fungi (like mushrooms), bacteria, and other plant material. They are also present in oats, other grains, and dairy products.

When you consume foods rich in beta-glucans, your immune system flourishes. Beta-glucans are immunostimulants, meaning they support the function and responsiveness of immune cells. These micronutrients support the normal activity of neutrophils, which help maintain your health.

Your immune response can be primed by molecules like beta-glucans. They train your innate immunity (your ancient immune system) to react to real threats with harmless stimuli. Now “awake” and alert to foreign triggers, your immune system is in a heightened state of awareness.

Macrophage (a type of white blood cell) activity is also stimulated by the presence of beta-glucans. Together (and with the help of beta-glucans) neutrophils and macrophages play an important role in maintaining your immune health.

And you don’t have to dig too deep to find beta-glucan-rich foods. Beta-glucans are large polysaccharides (large sugar molecules) that are added to foods to increase their fiber content. Many cereals, baking goods, instant oatmeal, and milk products are fortified with beta-glucans. Increase your awareness of dietary sources of beta-glucans so you can practice healthy immune nutrition.

Fruits and Veggies: Vitamin C

Vitamin C is a powerful antioxidant. And it also works with your immune system to maintain your health. Neutrophils (yet another of the five major types of white blood cells) have a high concentration of vitamin C. They use it to reduce free radicals and other toxic oxygen species to protect themselves when they are out protecting your health.

The presence of vitamin C also triggers the activation—or maturation—of leukocytes.  These important immune cells are part of your body’s natural defenses that keep you feeling your best. Working in tandem with antibodies, leukocytes can direct other cells in your immune system. This essential function helps maintain healthy immunity.

They’re bright and vibrant, so foods rich in vitamin C are easy to spot when you are out shopping. Citrus fruits, colorful peppers, spinach, and broccoli are all excellent sources of this essential vitamin and antioxidant. You can make it a snack or a side dish. So, look out for your immune system and add vitamin C to your shopping cart.

Protein: B Vitamins and Zinc

This group of essential vitamins and a mighty mineral partner with your immune system to keep you healthy and feeling your best. B vitamins do this by supporting a healthy metabolism and helping to produce white blood cells. Zinc supports the development of immune cells and acts as an antioxidant—defending your body by destroying free radicals.

B vitamins are a class of their own. These eight immunity nutrients are commonly found in tuna, beef liver, chicken, and turkey meat. As mentioned above, they play an important role in a healthy immune system because they help your body manufacture white blood cells. B vitamins also support the creation of hemoglobin. This protein helps red blood cells carry oxygen throughout your body.

Zinc aids in multiple immune system functions. In your body, zinc stimulates the production of immune cells. It also helps these cells initiate a proper immune response. Macrophages also rely on zinc to help them play their normal role in your body’s defenses.

Free radicals are no match for zinc, either. By helping to reduce toxic oxygen species, zinc can minimize free radical damage.

The essential mineral can be tricky to locate, though. Zinc is hiding in foods like oysters, crab, and lobster. But if high-priced seafood doesn’t suit your budget or taste buds, grab a box of healthy, whole-grain breakfast cereal instead. Many fortified and whole grain breakfast cereals contain a significant amount of zinc.

Eating immune supporting foods loaded with B vitamins and zinc help your immune system by supplying red blood cells with hemoglobin and increasing the number of fighter cells like leukocytes and neutrophils. Learn to rotate macronutrient choices so you get some variety while focusing on immunity nutrition.

Immunity Nutrients Shopping List

Immune supporting micronutrients can be acquired through healthy eating. If you have trouble locating the foods below, or avoid them for any reason, you may need some help supporting immunity. Nutritional supplements can also provide these necessary micronutrients for immune support. Supplementation can help your body stay topped off with the immunity nutrients of which you need more.

But start with this shopping list, which provides ample dietary sources of immunity nutrition. You should be able to find foods rich in beta-glucans, vitamin C, B vitamins, and zinc at the grocery store, farmer’s market, or in your own garden.

These nutrients are hiding in plain sight. All you need to do is eat and enjoy. Bon Appetit!


  • Whole wheat bread
  • High-fiber whole wheat cereals
  • Oats
  • Mushrooms
  • Seaweed
  • Low-fat dairy products
  • Low-fat meat products

Vitamin C

  • Oranges
  • Kiwifruits
  • Grapefruits
  • Red peppers
  • Green peppers
  • Broccoli
  • Brussels sprouts
  • Spinach

B Vitamins

  • B vitamin fortified cereals
  • Liver
  • Chicken breasts
  • Salmon
  • Eggs
  • Yogurt


  • Oysters
  • Lobster
  • Crab
  • Beef
  • Chickpeas
  • Cashews
  • Kidney Beans

Your immune system is always working to keep you healthy. Understanding how your body protects itself gives you ammunition to fight off germs. There are a lot of immune system myths out there about keeping yourself healthy. Do your research to separate the fact from fiction so you don’t fall for these immunity myths.

Start on the right path by reading this list that busts seven of the most common immune system myths. Learn what does and doesn’t make you sick. And discover the facts about steps you can take to stay healthy year-round.

Immunity Myth 1: Cold weather makes you sick

Sure as the changing of the seasons, you can be certain you’ll wind up catching something in the winter. The question is, why? People often contract common cold viruses in cold months. So, you might believe low temperatures are responsible for making you sick.

Not so.

A link does exist between chilly temperatures and sickness, but it is a correlation, not a cause-and-effect relationship. Most likely the changes in behavior associated with cold weather are what trigger these seasonal surges.

Cold weather keeps people indoors for longer periods of time. This leads to the spread of germs between people who are in close contact. Think family members, co-workers, classmates, or the people with whom you share a bus ride. Proximity to others is the primary way viruses spread, regardless of outdoor temperature.

A similar pattern occurs when children return to school after summer break, or when you start attending a new gym. Physical closeness to lots of people increases the chance you’ll catch a bug (whether it’s warm or cold outside.)

Some research highlights that cooler temperatures provide a better living environment for specific viruses. Rhinovirus (the microbe responsible for the common cold) is usually living dormant in your nasal passages waiting for more suitable temperatures. When cooler weather comes along, it wakes up and reproduces.

If you stay inside due to the weather, an inadvertent cough or sneeze sends the cold virus into the air you share with others. Because colder weather brings people closer, a sneeze might be all it takes to spread a cold. But the temperature change was only part of the equation.

Immunity Myth 2: Seasonal allergies are a sign of a weakened immune system

The opposite is true. Seasonal allergies are the result of an over-reactive immune response mistaking small particles in the air for harmful microorganisms. Consider allergies the hallmark of an over-vigilant immune system, rather than one slacking off.

It can be difficult to distinguish allergies from other upper-respiratory issues. They share many of the same symptoms, but are not contagious. You might experience a headache, congestion, runny nose, watery/itchy eyes, or even a sore throat. All are symptoms of a cold, too.

The difference is allergies aren’t triggered by bacteria or viruses. Harmless particles like dust, pollen, or mold are introduced to your body when you breathe. If you have seasonal allergies, your immune system responds to these particles like it would a potential pathogen.

To minimize your allergy symptoms, try to identify the source of your allergy. If it is pollen, avoid blooming plants. Dust allergies can ramp up when it is windy outside. So, consider protecting your mouth and nose with a mask on windy days.

These allergies are seasonal, as their name implies. That means time will start to bring relief. Allergy symptoms can be controlled well with proper medication prescribed by a physician. Talk to a doctor and see if they can help you find a way to manage your seasonal allergies.

Immunity Myth 3: Handwashing “kills” viruses

You might be surprised to learn that washing your hands doesn’t actually kill viruses. Viruses aren’t alive, which means they can’t replicate on their own, but washing does rid your hands of viruses in another way.

Soap adheres to the membrane, or outer wall of viruses. And soap molecules also compete with the lipids within the virus membrane to help pry it apart and render it harmless. This stickiness means microbes can be rinsed away with water. When you wash your hands, you are literally washing off the viruses that can make you sick.

If you want a refresher on how to properly wash your hands then check out this handy guide. Proper handwashing technique is important, and there’s more to it than you might think.

After you are done washing your hands make sure you dry them thoroughly. It is harder for viruses to transfer from dry hands. Wash and dry often throughout the day. Handwashing won’t kill the germs that can make you sick, but can effectively get rid of them.

Immunity Myth 4: Hand sanitizer is more effective than handwashing

Handwashing with soap and water is the most effective way to prevent the spread of bacteria and viruses. When handwashing is not available, hand sanitizer is a good backup option.

Unlike handwashing, hand sanitizers do destroy microbes. The alcohol in hand sanitizer deactivates viruses and keeps them from transferring from your hands. Hand sanitizer made of at least 60 percent alcohol effectively kills bacteria and microbes on your hands.

To make the most of your hand sanitizer, try to remove visible dirt and debris first. Wipe your hands off with a napkin or cloth before using sanitizer to clean. Dirt and oils from your skin make hand sanitizer less effective at killing microbes.

Hand sanitizer isn’t as effective at removing microbes as hand washing, but it is practical. Having hand sanitizer with you is a convenient way to clean your hands on the go. When you are out shopping or driving in your car, you can’t always stop to wash your hands. Use hand sanitizer in these situations to keep yourself safe from germs.

Immunity Myth 5: “Feed a cold, starve a fever”

This refrain is one of the more pervasive immune system myths. Your body needs adequate fuel to fight off infections of any kind. Imagine trying to fight a battle on an empty stomach. That’s how your immune system will behave if you restrict what you eat when you’re sick.

There isn’t much evidence to support the notion that fasting reduces a fever. In fact, your body’s calorie demands increase when you fight off an infection. Your immune system needs energy from your diet to increase white-blood-cell production. The rise of your internal body temperature boosts your metabolism, too. This means you need more calories to keep up.

However, if you’re feeling sick you might not have a big appetite. This is completely normal. Don’t force yourself to eat if you don’t want to. You might end up feeling nauseous.

But whether you have a cold or fever, it is important to eat what you can when you’re sick. Stick to whole, nutritious foods if you’re under the weather. Many fruits, cooked vegetables, and protein are easy on the stomach and supply you with the essential nutrients your body needs. Choose those that sit well with you.

Immunity Myth 6: Chicken noodle soup will shorten your cold

As good as this sounds, a bowl of soup is not a cure of any kind. Chicken noodle soup is, however, a time-honored comfort food. Unfortunately, the soup itself boasts no magical healing powers—the plumage of the chicken used to make the soup doesn’t either.

Time, rest, and appropriate medication are the only ways to defeat an infection.

That isn’t to say chicken noodle soup is a bad idea. It’s a great way to deliciously acquire some hearty nutrition. It’s full of quality ingredients that can help fuel your body in its time of need. Antioxidants and vitamins from the veggies help support your immune system. And protein from chicken gives sustainable energy to aid in the fight.

Soups (and other hot meals) will help alleviate some of the symptoms of a cold. The steam from the broth can help clear the sinuses and heat can soothe a sore throat.

Other foods can provide similar relief. Hot tea, honey, rice, bananas, and applesauce are palatable and can settle an upset stomach. Try some of these foods the next time you’re feeling unwell. They won’t cure your cold on their own, but will fill you up with the nutrition you need to support your immunity.

Immunity Myth 7: Exercise weakens the immune system

Taking on an Olympic-style training program might throw your immune system for a loop. But regular, low-impact exercise can do your body good. A habit of exercise is a reliable way to prepare your body for germs that might come along.

White blood cells flourish when you work out. Exercise increases cell turnover in your body and stimulates the production of these important immune cells. After all, they’re the front-line troops fighting against viruses and bacteria.

Make it a goal to exercise for your immune health, and overall wellbeing. Be sure not to overdo it, as too much vigorous exercise can have a detrimental effect. Keep it simple with walking, jogging, or swimming. Just make sure to move your body every day to support your immune system.

Stop the Spread of Immune System Myths and Misinformation

Now that you know the false facts surrounding immunity, do your part to replace the myths with the truth.

Make sure you practice appropriate safety measures during times of increased viral spread. Demonstrate your knowledge about immunity myths by prioritizing exercise and eating nutritious foods to keep you feeling strong. Teach your family and friends about the importance of handwashing.

Bust the myths about your immune system and do what you can to help your body stay healthy.

Your immune system is in a battle every day. That’s its job.

You’re protected by a coordinated defense. Cells, proteins, and chemical signals join forces against bacteria, viruses, parasites, and other pathogens. And your immune system also helps in wound healing, cellular and tissue turnover, and repair.

A healthy, functional immune system is a complex machine. It contains many layers, subsystems, tissues, organs, and processes. But a basic understanding can help you see what you need to maintain healthy immunity.

Barriers to Entry

Imagine your body as a castle to be defended. The first layer of defense are your physical and chemical barriers. They’re the high, thick walls that turn away many intruders.

Your skin is the most obvious physical barrier. And it’s a good one. Your largest organ is a waterproof covering that protects you against pathogens. Skin’s construction, substances on the surface, and other compounds in deeper layers help it provide protection.

Skin does a good job, but there are other paths into the body. That’s why other physical barriers exist.

Your upper respiratory tract has tiny hairs called cilia. They move potentially harmful material away from your lungs. Your gut barrier blocks absorption of possibly harmful substances. And your excretory (bathroom) functions physically expel pathogens.

Mucus blurs the line between the physical and chemical. Whatever category you put it in, mucus is an effective trap for invaders. It’s produced by membranes throughout your body. This thick, gluey substance is your body’s sticky trap, grabbing microbes and not letting go.

Other chemical barriers include: tears, saliva, stomach acid, and protective chemicals produced inside of cells and in your blood.

Immunity in General: Your Innate Immune System

The innate immune system is sometimes called the non-specific immune system. This subsystem of your larger immune defense is loaded into your genetic code. That’s the innate, or inherent, part. And it provides more general protection, destroying any microbes that enter your body. That’s the non-specific part.

Your cellular defenses kick in if a pathogen survives your physical and chemical barriers—which could also be considered part of the innate subsystem. That’s where phagocytes (a specific type of immune cell) come in. These white blood cells act like guards patrolling your body and destroying invaders.

These cells are found throughout the tissues of your body. They kill pathogens through a process called phagocytosis. It’s complicated, but there’s a simple way to understand it.

Phagocytes eat the invading microbes. They were named phagocytes for a reason—phago comes from the Greek for “to eat.” Phagocytes ingest or engulf the invaders. While trapped, several killing mechanisms are deployed to destroy the pathogen.

Some phagocytes have receptors that distinguish between healthy cells and potentially harmful substances. (They also deal with turnover of dead and dying cells.) Other pathogen eaters are chemically signaled to sites where they can be most useful. Phagocytes even help with the cleanup and repair after the invaders are destroyed.

Adaptive Immunity

Your adaptive immune system is like an immunity database. After encountering a specific pathogen, you have immune cells that can recall the best way to destroy it. That’s why it’s also referred to as specific or acquired immunity.

The original pathogen exposure can be intentional or accidental. That doesn’t matter. A normal, healthy response starts with an antigen. Think of an antigen as the bar code of each cell. Just like every item in the grocery store has a unique bar code, each cell type has a unique antigen code to identify it.

These antigens—mostly proteins—can also identify pathogens. Our immune system has learned to read these antigen codes. When they recognize something as being foreign, they initiate an immune response.

Each unique antigen triggers the creation of a unique antibody. The y-shaped antibody binds back to the corresponding antigen and marks the invader for attack by other immune cells. Some antibodies can even take care of business for themselves.

Lymphocytes (another specific type of immune cell) are the main cells involved in your adaptive immune system. Two types of white blood cells—T and B cells—are produced in your bone marrow. They can attack and kill pathogens on their own, or assist other white blood cells in the responses.

T and B cells form the basis for your body’s immunity memory bank. B cells present antigens and create and release antibodies. Memory T cells—those that survive previous attacks—quickly and effectively respond to known pathogens. Together, they help your immune system efficiently and effectively destroy known bacteria, viruses, or other pathogens.

Defend Your Immune System

Above, you’ve read about the way a normal, healthy immune system functions. But your defenses can be impacted by your environment, diet, stress, sleep, travel, and other lifestyle factors.

Healthy immune function is a whole-body effort, and maintaining it takes a holistic approach. Here’s a few things that can help:

  • Get at least seven hours of sleep a night—and avoid pulling any all-nighters.
  • Exercise regularly to promote memory cells, enhance skin immunity, and mobilize immune cells.
  • Minimize stress as much as possible or practice healthy coping strategies, like exercise.
  • Eat a healthy, balanced diet full of fruits, vegetables, and lean proteins to provide essential micro- and macronutrients and important phytonutrients. A healthy diet (that includes healthy amounts of fiber) will also provide your microbiome with what it needs to maintain good gut barrier function.
  • Practice good hygiene, including frequent handwashing, so your body doesn’t have to deal with as many pathogens in the first place.

The first three words that come to mind when you read “vitamin D” are probably essential, sunshine, and bones. That’s a good start, but it fails to fully capture the diverse duties of one of your body’s most necessary nutrients. And one area that’s often overlooked is the connection between vitamin D and immunity.

Vitamin D’s role in supporting and maintaining bone health is the basis for its classification as an essential vitamin. However, newer research has revealed how vitamin D supports immune health. This happens through the fat-soluble vitamin’s involvement in helping regulate several important processes related to normal cellular repair and healthy immune response. These findings, coupled with the observation about the health status of those deficient in vitamin D, have led to an increased interest into vitamin D’s role in supporting and maintaining good immune health.*

One Vitamin Supporting Two Sides of Immunity

The significance of vitamin D’s role in immune function was established and confirmed following the discovery that nearly all cells of the immune system contain vitamin D receptors. The effects of vitamin D on immune cells are very complex, but research has shown its functions support the innate and adaptive immune system.*

The innate (or first-response) immune system’s main function is to protect the body using physical barriers, chemicals, and certain immune responses. It also includes immune cells (neutrophils and macrophages) that can act as your normal, front-line cellular defenses. Although effective and quick, the innate immune system’s approach can possibly cause some collateral damage and lacks the inability to identify repeated exposures.

The adaptive immune system is slower, but more specific and methodical. Your adaptive response includes specific immune cells that coordinate the destruction of infected cells (T-lymphocytes) and that activate and secrete antibodies (B-lymphocytes). The adaptive system uses an immunological memory to quickly and vigorously defend against repeated exposures. This forms the principle behind natural or lifetime immunity after antibody-producing immune interactions.

Learn more about T cells and adaptive immune response and review the basics of your immune system.

4 Examples of How Vitamin D Supports Immune Health

Going through all of vitamin D’s roles in immune health could take up an entire textbook. But if you remember these four important impacts the nutrient has in helping support healthy immune defenses, you’ll be well on your way to understanding how important the sunshine vitamin is for maintaining health.*

1. Vitamin D supports the maturation and function of key immune cells*

Innate immunity is a coordinated effort involving many different cellular players. Macrophages and their monocyte precursors as well as T-lymphocytes (cytotoxic T-cells) all play vital roles in your innate immune response and cell-mediated immunity (those that occur without antibodies from your immune system’s memory).

Vitamin D is an important cog in the mechanics that support the normal maturation and differentiation of monocytes into macrophages. Once grown into specific macrophages, these immune cells support a healthy first-response cellular immune defense. They also participate in clean-up operations—eliminating or assimilating cellular waste. In addition, macrophages secrete a key immune protein called cathelicidin. The normal cathelicidin production of activated macrophages is largely dependent on the presence of adequate levels of vitamin D.*

2. Vitamin D supports antigen presentation*

In order to prompt defensive actions, immune cells—like lymphocytes—need to be exposed to antigens (specific proteins that alert the immune system). The most effective antigen-presenting cells are known as dendritic cells.

A major function of dendritic cells is to capture, process, and present antigens to the adaptive immune system and initiate T-cell-mediated immunity. Dendritic cells are critical to the development of immunological memory and tolerance. Vitamin D plays a key role in supporting the healthy maturation and regulation of human dendritic cells.*

3. Vitamin D plays a role in supporting your immune system’s natural ability to produce proteins required for it to function at an optimal level*

This connection between vitamin D and immunity provides biological weaponry your immune system needs to help keep you healthy. Vitamin D helps maintain proper regulation over production of specific proteins that support healthy immune function.*

A good illustration of this is seen in the lungs, where immune cells and epithelial cells are known to contain large numbers of vitamin D receptors. Researchers studying these vitamin D receptors in lung tissue found that activated vitamin D helps support the activity of a compound that maintain healthy immune function in the lungs. It also helps support the production of a protein that assists cells to perform their natural, normal abilities.*

4. Vitamin D lends a helping hand to your T-cells

Vitamin D’s ability to help support normal, healthy development and differentiation of immune cells extends to adaptive immunity, as well. T-cell types are helped by vitamin D.*

T-cells start out as inactive, or naïve, cells. To be helpful to your body’s defenses, they must first transition into either killer cells or helper cells to actively participate in immune response. The natural process of mobilization and activation to keep you healthy is supported by vitamin D. The essential vitamin also helps maintain the proper migration of T-cells to and away from specific tissues, like the skin, digestive tract, and lymph nodes.*

Using What You Know About Vitamin D and Immunity

This is a very basic overview of vitamin D’s role in immune function. The ways vitamin D helps maintain the health of the immune system is very complex and is a matter of balance. You don’t want your immune system too cranked up or too lazy. Maintaining a healthy vitamin D level is important for helping maintain the overall balance and normal functioning of your immune system.*

If you are unsure about your current vitamin D status, it is important to get it checked by your preferred health professional. Blood levels of 30 ng/ml-50 ng/ml are considered optimal by most experts.

So to help your immunity, keep your body well-stocked with vitamin D. Do it through smartly getting some sun. Also adjust your diet to include more foods enriched with vitamin D. You can also turn to supplementation if you live in higher latitudes or if poor food choices cause gaps in your diet that make optimal levels hard to achieve.*

*These statements have not been evaluated by the Food & Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Stress is unavoidable and plays a big role in your life. Some stress can be good—motivating you to accomplish your goals and complete necessary tasks. But a lot of stress is bad, leaving you feeling overwhelmed, even sick. That’s because the negative effects of stress on immune function are significant.

Think about your life. Feeling good and being stressed don’t usually happen at the same time, right? That’s because stress on your body and mind can weaken your immune system. Why is that? Your body goes into overdrive so you can perform at maximum power to tackle your stressors, meaning the strength of your immunity can suffer.

Even though that’s very simplified, it’s a good start to a deeper conversation about how stress impacts immune function. First, you’ll want to understand the way your body responds to stressors so you can see how stress and immunity are connected. Then you’ll learn ways to improve your reaction to stress to help keep you feeling healthy through difficult times.

The Language of Stress

Learning some of the terminology used to talk about stress will give you a better grasp of your body’s natural responses. Here are the basics:

  • Stressor: Any stimulus that causes stress. There are two kinds of stressors: physical and psychological. Physical stressors are stress on the body. Psychological stressors are stress on the mind.
  • Hypothalamus: An important command center in the brain. This region is about the size of a penny and sits in the middle of the brain. It controls the activity of the pituitary gland and regulates hunger, thirst, sleep, body temperature, and many emotions.
  • Pituitary Gland: The master gland responsible for releasing most of the hormones in your body.
  • Adrenal Glands: Triangular glands that rest above the kidneys that are responsible for releasing cortisol.
  • Cortisol: The primary hormone released into the blood in response to stress.

How Your Body Handles Stress

Your body has a built-in response protocol that springs into action every time you experience stress. It begins when a stressor comes along and puts pressure on your mind or your body.

The part of your brain that recognizes stress is called the hypothalamus. As soon as the hypothalamus recognizes a stressor, it sends a message via neurons to a neighboring region of the brain called the pituitary gland. This gland registers signals from the hypothalamus and tells the adrenal glands (above your kidneys) to increase the amount of stress hormones circulating in the blood.

That’s the basics of your body’s natural stress response. To understand it further and connect the dots between stress and immune function, let’s explore your primary stress hormone—cortisol.

This important hormone works by providing an energy boost during periods of stress. But the effects of cortisol are temporary. Once the stress wears off, so does the energy assistance.

Another way cortisol helps your body manage stress is by powering down any non-essential operations in the body. Unfortunately, some of your immune functions are put on pause thanks to cortisol. It does this in an effort to conserve energy while under stress, but this makes stressful periods the perfect time for germs to settle in.

How Stress Impacts Your Immune Function

Cortisol works temporarily when the stressor you experience is short-lived, like running late for an appointment or competing in a triathlon. That makes the impact on your immunity minimal. But when stress lasts longer, like days or weeks, increased cortisol levels can start to have more negative effects.

Elevated cortisol suppresses your immune system by reducing production of white blood cells. Without white blood cells on the hunt for germs, your response to an infection is much slower. So, long periods of cortisol elevation can leave you susceptible to illnesses you otherwise wouldn’t succumb to. That’s why it’s common to come down with a cold after a period of high stress.

College students preparing for final exams provide a good example. Many students find they develop a cold in the days following the end of a college term. But why?

The stressor (final exams) initiates their bodies’ stress response. Cortisol levels rise and stay elevated for a longer period while they study—maybe even for a few weeks. During this stressful time, their immune systems are suppressed so their brains can harness as much available energy as possible to tackle the stress in the form of final exams.

Running at this low capacity provides germs an easy opening to infect healthy tissue and bring on illnesses like the common cold. And the symptoms, which are partly felt as part of your immune response, come on once those stressful tests have passed.

College tests aren’t the only kind of long-term stress, of course. You may notice a similar pattern in your own life. Moving to a new city, having a baby, changing jobs, and other life challenges are all common long-term stressors. And since any prolonged stress elevates cortisol levels and suppresses immunity, germs can exploit your weakened immune system in these times of intense pressure.

Alleviate Stress for Immunity’s Sake

Learning to manage the stress in your life can help keep cortisol levels down and protect your immune system. There are many activities you can try that bust through stress and are good for your overall health, too.

Meditation is one of the most effective stress-management strategies. Just a few minutes concentrated meditation daily can significantly reduce blood cortisol levels and help you feel peaceful and serene. It can help support your immunity, too.

In one study, researchers found people who meditated every day developed more antibodies to a flu virus than those who didn’t. So, spend a few minutes every day disconnecting from the busy world and especially turn to meditation when you feel stressed.

Exercise is another tried-and-true way to alleviate stress. You already know many of the benefits of moving your body every day. Now you can add stress-relief to the list. (Check out this story for even more options for dealing with stress.)

If none of the lifestyle remedies work, a conversation with a mental-health professional should be your next step. Talking with a counselor or social worker in a therapy setting can help you confront the stressors in your life and find effective methods for managing them.

No matter your choice of stress-management technique, it’s time to better equip yourself to protect your body—and immune health—from the effects of stress.

Editor’s Note: The following story is focused on viruses, in general. Though a few common viruses are used as examples, this is not meant to be a deep exploration of specific strains or a tool for diagnosis or treatment of any specific virus.

Viruses are little germs that can have big impacts on your health. Informing yourself about how viruses work helps you understand part of what your immune system deals with daily.

Start with some answers to common virus questions to boost your knowledge about what they do, how they work, and the way they can possibly be harmful. You’ll find out the basics about viruses, how your body responds to them, and the way herd immunity to viruses works.

Question: How are viruses and bacteria different?

Answer: The two kinds of microbes that most frequently make you sick are viruses and bacteria. Both are microscopic and trigger an immune system response. But viruses and bacteria could not be more different.

Let’s start with bacteria. These single-celled living organisms have a cellular membrane. They thrive in a wide temperature range, meaning you can find them almost everywhere. Bacteria have circular DNA that they use to reproduce. They feed on organic and inorganic matter, decaying plant and animal cells, even the food you eat. Some bacteria can even photosynthesize just like plants do.

Bacteria aren’t always bad. They can be beneficial to your body, too. In fact, the majority of bacteria aren’t harmful at all. Your skin and gut are teaming with bacteria, which you might know better as your microbiome. The microbes that live on your skin help clear away dirt and dead skin cells. In your intestines, bacteria help digest your food.

Some bacteria can be harmful, especially when they grow in places they shouldn’t. That’s why, generally, bacterial infections affect localized areas of the body. This can irritate or damage healthy tissue. Examples of common bacterial infections are strep throat, food poisoning, and ulcers.

To help battle bacterial infections, your doctor might recommend antibiotics. This kind of medicine kills the bacteria making you sick and disrupts its reproduction so it can’t spread.

Viruses are much smaller than bacteria and are not considered living organisms. They are infectious agents with only a protein shell and a strand of RNA or DNA, depending on the type of virus. They do not reproduce on their own—like bacteria do. Instead, viruses need a host cell to do the reproducing for them (you’ll learn more about that below.)

While bacteria can be either harmful or beneficial, most viruses only make you sick. Some common viruses are rhinovirus (common cold), varicella (chicken pox), and herpes (cold sore). Viral infections cause symptoms throughout the entire body, like congestion, aches, cough, and fatigue.

Antibiotics do not work against viruses. Instead, you must rely on your immune system. Over time, your immune system will develop antibodies to recognize the virus and prevent it from infecting healthy cells. This is why it pays to practice healthy habits on a consistent basis to help maintain your immune health.

Some viruses can be prevented through vaccination. Vaccines can help your body create antibodies before you’re ever exposed to the virus in your daily life. This way your body will be ready to fight off the specific virus if it ever comes along.

Question: How do viruses work in your body?

Answer: Since viruses are not alive, they rely on host cells to complete their lifecycle. They act like parasites—infecting healthy cells, using them to reproduce, and destroy them when they are done.

Viruses are tiny packages of DNA or RNA (genetic material) that travel in a protein shell. They are masters of disguise, so the protein coat of a virus is often mistaken by the cells in your body as a nutrient. Healthy cells are fooled into attaching to viruses with their receptor proteins. Then the virus enters the cell.

Once inside the host cell, the virus can release its genetic information. Viruses need to make copies of genetic material to reproduce. So, they hijack the cell’s own reproduction system. Now the host cell is making copies of the virus DNA or RNA, instead of the cell’s own genetic material.

After the virus reproduces in the cell, it breaks free, destroying the host cell in the process. The virus uses the membrane of the host cell to travel through the body undetected by the immune system. This is why it is difficult to treat viruses. They are hard for the immune system to identify and target.

Your body eventually learns to tell the difference between viruses and healthy cells. When it does, your immune system creates antibodies. These little proteins mark the virus. Antibodies lead immune-system agents like white blood cells to the virus so your defense team can wipe them out—along with the affected cells.

Question: What are symptoms?

Answer: Symptoms are the physical signals your body creates to tell you something is wrong. They alert you to possible infection by a bacteria or virus. Symptoms improve over time as your immune system eliminates the infection from your body.

Most symptoms are triggered by germs that irritate healthy cells. They can cause a sore throat, stimulate mucus production, and raise your body temperature. But the symptoms you experience when you’re sick can actually help your body fight the infection. See how your immune system works with symptoms to protect you from germs.

  • Fever: Infections trigger an increase in body temperature. A fever is uncomfortable, but it’s a strategy your immune system uses to kill viruses. Some germs have a hard time living in high temperatures, so a fever makes your body a difficult place for a virus to survive.
  • Runny nose: When the mucous membranes lining your nasal passages are injured by a virus, you experience a runny nose. That’s because your body produces a lot of mucous to trap the germs and flush them out. A runny nose is a sign your immune system is working hard to push back against an infection.
  • Coughing: Your respiratory system has a reflex that expels germs from your body. If the cells in your airway detect an invader, they can trigger a cough. Forcibly coughing removes dust, bacteria, and viruses from your throat and lungs. Coughing also helps you remove excess mucous from your nose and throat.
  • Sneezing: Just like coughing, sneezing is a reflex. It’s a powerful immune response that kicks germs out of your nose—fast.

Question: Why do different people experience different symptoms?

Answer: The symptoms that follow an infection aren’t the same for everybody. Genetics has a lot to do with how your body handles sickness. And since no two people have the same genes, everyone responds to germs differently.

Your genes influence how your immune system fights viruses and bacteria. Immunity begins in the womb with antibodies to germs inherited from your mother (called passive immunity which is temporary for a newborn). Information from every illness you get is stored in your genes so your immune system can adapt. That way you can produce antibodies to mark infections in the future.

So, when you experience symptoms from an infection, your genes likely haven’t encountered the germ before. If someone else has already developed an immune response to that infection, they may never manifest symptoms.

Lifestyle is another factor that can affect how different people experience symptoms—especially smoking. When it comes to colds, most people’s symptoms recede fairly quickly. Non-smokers will experience minor coughing and congestion that resolves over time.

But smokers can have a different experience. Smoking damages the cells lining the nose, throat, and lungs. And it significantly weakens the body’s immune response. The damaged tissue takes longer to repair, which make symptoms like coughing and congestion last longer. That’s why it can be very difficult to overcome a cold if you’re a smoker.

Question: Can treating the symptoms of an illness prolong the infection?

Answer: The jury is still out on this one. In most cases, there isn’t much evidence to suggest that treating the symptoms of an illness make it last any longer.

Some more serious viral infections (like the flu) can take a while to clear up. That doesn’t have to do with the medications you use to treat them. Unfortunately, it takes even the best immune systems time to kick the flu.

Symptoms like congestion and a cough grow old quickly. So, it’s reasonable to seek relief. You can feel better quickly with decongestants that help clear your nose and throat or a cough suppressant. These kinds of treatments don’t directly interfere with your immune response.

Some infections require more potent medication. Bacterial infections like strep throat need antibiotics to kill the bacteria making you sick. These medicines shorten the life of the infection, and help you feel better, too. They target the source of the infection (the bacteria) and eliminate it from your body.

In the case of steroid medications, you might notice an increase in the time you spend sick. Steroids treat inflammation, which can sometimes be caused by an infection in the body. This represents a temporarily suppression of your normal immune response, which can make the infection causing the inflammation to last a little while longer. They are used on a case-by-case basis, depending on the infection.

Question: When is it necessary to treat a fever?

Answer: If you’re sick with a fever, you might be better off letting it run its course. Using fever-reducing medicine might make sense short term. But in the long run, you hinder your body’s natural reaction to infection.

Fevers happen when your body temperature increases to slow the spread of a virus or bacteria. Germs thrive at normal body temperature. So, cranking up the heat is a good way to force them out. Reducing your fever makes your body a more hospitable environment for the pathogens that make you sick.

The general recommendation is that if your fever is low-grade (under 101° F/38.3° C for children, and below 103° F/39.4° C for adults) try to hold off on the fever reducers. Let your body do its thing to fight off an infection. Should your fever climb higher, contact your doctor. They will instruct you on which fever-reducing medications to use.

If your feverish child stops drinking fluids, appears listless and won’t make eye contact with you, contact your doctor immediately.

Question: Can you catch the same virus more than once?

Answer: Yes and no. Viruses are prolific and have many subtypes and species. While you can have the same type of virus multiple times, you may only feel sick when you encounter a new strain or subtype.

Rhinovirus, the kind of virus that causes common colds, has hundreds of unique subtypes and strains. Every time you come down with a cold, your immune system is fighting the specific strain that made you sick. And at the same time, you’re developing antibodies to mark that subtype of the rhinovirus.

Should you come in contact with the same strain of cold virus again, antibodies will tell your immune system to tackle the virus. However, if it’s a new version of the virus, then you could be out of luck.

Viruses are constantly mutating as a means of survival. Like parasites, their goal is to take over host cells and use the host DNA to reproduce. As soon as your immune system learns to block a virus, another version can pop up that may go undetected. This ability means you could get sick with the same kind of virus again.

Question: How does the immune system communicate to coordinate responses to viruses?

Answer: Constant cellular communication is a key to maintaining your overall health. And your immune system is no different.

Let’s start with the basics of immune system communication and its two main forms—direct receptor contact and messenger proteins.

Direct Receptor Contact

Like most cellular communication, your immune system’s ability to talk relies on receptors. These special sites on the outside of a cell make it possible to receive chemical signals and messenger proteins. They also allow cell-to-cell connection where transfer of information is possible.

Your immune cells have different receptors. T cells (an immune cell that matures inside the thymus) use their special receptors—aptly named T cell receptors—to gather information from infected cells. This is what allows other immune defenders to identify a potential pathogen.

Receptors are so critical to T-cell function that they’re classified by the receptors presented. T cells with a CD4 receptor are helpers, used to marshal your immune forces. CD8 receptors are a hallmark of the cytotoxic T cells doing the work of neutralizing infected cells.

These different T cells seek out and connect to specific receptors on infected cells. Depending on the type of major histocompatibility complex (a receptor on an infected cell), a helper or cytotoxic T cell links up. So, the receptor type and the resulting connection drives an important element of immune system communication.

Messenger Proteins

Direct contact isn’t always necessary or possible for a coordinated immune response, though. That’s why your immune system also talks amongst itself using special proteins called cytokines.

Immune messenger proteins can travel long or short distances, but signal different actions. Some cytokines act as a green light for a variety of immune-system responses. Others—called chemokines—are flashing beacons to recruit and guide more immune cells to a situation.

Interferons are immune-system-communication molecules sent out by a variety of cells involved in an infection. Infected cells—both immune and regular bodily cells—sent out unique versions of these proteins. The immune cells rushing to respond do, too. While specific in form and function, interferons generally boost the number of T-cell-binding receptors to help flag infected cells and guide your immune response.

This is, by no means, a comprehensive guide to your immune system’s complex language. But it’s a start. And it better helps you understand how these forms of communication combine to coordinate the flurry of immune activity when your body senses an invasion. That’s important for an effective, efficient response.






















Your body is a complex, hardworking machine. It works best when all systems and internal mechanisms operate in concert to keep your body running at its peak—from your skin and skeletal structure to your cardiovascular and central nervous systems. But, like any machine, your body’s natural aging process will begin to affect many of these systems.

As your body’s natural defense, there is no one system that affects your entire body through natural decline more than an aging immune system. Over time, your immune system naturally deteriorates through a process called immunosenescence. While defined as the impact of age on immune function, it is a process that, like your immune system, is brought about by the workings—or lack thereof—of many smaller parts.

To make sense of what happens to immune health as you age, it might be important to have a quick summary of your immune system.

Innate vs Adaptive Immunity

Your immune system is made up of white blood cells, tissues, and organs that combine forces to defend the body against internal and external stressors. General immune system response is often broken down into two parts: innate and adaptive immunity.

The innate immune system (or non-specific immune system) is exactly what you’d think it is based on the name—this is what you are born with. Your innate immunity is developed with the help of your parents and genetically passed along to your offspring. It is made of physical and chemical immunity barriers, like your cough reflex, skin, mucous membranes, and stomach acid.

Your innate immune system is not as powerful as other parts of your overall system, but it is your first line of defense and rapidly attacks any and all foreign substances, called antigens. Any antigens that break through these defenses then go against your adaptive immunity.

Your adaptive immunity is individual to you and continually changing. As you are exposed to various antigens throughout your life, your immune system builds and catalogs a defense against those particular antigens. When your body is bombarded, B and T lymphocytes (B and T cells) are released from your thymus gland. B Cells produce antibodies and T cells directly attack the antigens. Together, these white blood cells work toward protecting your body from harm, including threats from viruses and infections, and remembers how to fight what you’ve already been exposed to.

Immunity and Age

As you naturally age, there are a few things that happen in your body as immunosenescence takes place. Your thymus—which is biggest in size throughout puberty—shrinks, limiting T-cell production. The number of T cells you have does not decrease as you age, but their function does. Because these cells are part of the team tasked with directly attacking antigens, the risk of becoming ill increases. They still remember how to fight what they’ve seen in the past, but you need new ones to fight new exposures—or even mutated types your body has already adapted to, like a new strain of influenza.

Not only are there fewer new cells created, but they are also slower to react to new threats. As a result, it takes longer for your body to figure out a plan of attack to deal with threats once they are detected. This is why infections and illnesses are more frequent and severe as you age than they were when you—and your immune system—were young.

But it isn’t just the adaptive immunity that slows down. Similarly, the innate system is slower to respond and react to internal and external frontline issues. Take, for example, a surface-level cut. When you’re young, white blood cells are quickly deployed to clot, scab, and remodel the skin. But, as you age, this process naturally slows, leaving some prone to inflammation and infections—two of the main factors in a weakened immune system.

Support an Aging Immune System

Although a slowed immune system is a natural part of aging, it doesn’t mean deterioration is inevitable. In fact, depending on certain factors, your body may be biologically younger than your calendar age.

While your chronological age is measured by counting the years since birth, biological age—or how you age—is a measure of your overall health when factors like lifestyle, diet, genetic risk of developing age-related ailments, and more, are all taken into account. This is why two people born on the same day may appear to age differently.

There are certain aspects you can’t control about how aging may naturally affect your immune system due to genetic factors, but you can add (or take away) some key lifestyle habits to support to your entire body system.

Eat a Well-Balanced Diet

A diet full of fresh fruits and vegetables, whole grains, healthy fats, and lean meats can help your immune system keep running strong. A variety of fruits, vegetables, and whole grains also provide necessary dietary fiber to support a healthy gastrointestinal tract. This is especially important in establishing a strong immune response to outside stressors. That’s because it’s directly impacted by pathogens and anything foodborne. Many of the foods most closely associated with the Mediterranean diet have been shown to help maintain your immune system.

Get Enough Sleep

A lack of adequate sleep means your body doesn’t produce as many infection- and inflammation-targeting proteins that help bolster and restore immune responses.


Being consistently active is one of the best ways to help your overall health. It is recommended adults complete about 150 combined minutes of moderate exercise each week. This is enough to aid blood flow and help immune cells migrate throughout your body.

Practice Good Hygiene

One of the easiest ways you can help your body fight against external stressors is to practice proper hygiene habits. Proper handwashing and other cleanliness habits help limit exposure to germs that could test your immunity.


Unchecked stress can impact your weight, sleep, and overall well-being, and it can also put added pressure on your immune system. Developing some simple stress management techniques can help you momentarily step away from stressful situations and reset.

Don’t Smoke

Smoking kills antibodies and antioxidants in your blood. It inflames your lungs, causing cells to divert from other uses.

Drink Alcohol in Moderation

Excessive drinking lowers your white blood cells’ ability to kill antigens and fight infection.

The bottom line is a healthy immune system and an overall healthy lifestyle go hand-in-hand. Preparing for the impact of age on immune function is a whole-body effort, and maintaining it takes a holistic approach.

For more, take an in-depth look at ways to further support your immune system, no matter your age.

























Feeling sick isn’t fun. That’s why it’s so important to protect your immune health. There are behaviors to do every day to support your immune system—you can find examples in this helpful story. But there are also immunity don’ts you should avoid.

Knowing what NOT to do is important. It can help you set boundaries and shape habits. So, check out these 12 immunity don’ts to see what you can do to help support your immunity.

Don’t: Skimp on Water

When you start feeling thirsty, your body is already dehydrated. Hydration is essential to a heathy body and powerful immune system. Without enough water, your body is less efficient and you feel sluggish and fatigued.

It’s hard to run an effective defense against germs with water in short supply. Water is necessary for the movement of mucus and phlegm, two barriers to viruses and bacteria. That’s because mucus and phlegm are sticky traps for microbes. This keeps germs from spreading to healthy cells.

Keep your body hydrated and happy by drinking at least eight glasses of water a day. Lots of water keeps mucus flowing. Your immune system needs that mucus to grab ahold of germs and help fight infection. Don’t forget to give your body enough water to do a good job.

Don’t: Blow Past Bedtime

As the proverb states, “Early to bed, early to rise, makes a man healthy, wealthy, and wise.” While an early bedtime might not guarantee financial success, it can keep you healthy.

Your immune system performs best when you give it enough sleep. A full eight-hour stretch allows your body time to regenerate and repair. Your immune system has important tasks to perform while you sleep, too.

So, don’t miss bedtime to help ensure you get adequate sleep. Also make the hour before bed as restful and peaceful as possible. Dim lights, turn off the television, and put down your phone. Relax and meditate to help yourself fall asleep faster.

Quality sleep is non-negotiable. If you need extra motivation to avoid staying up late, think of all the support a good night’s sleep gives your immune system.

Don’t: Touch Your Face


Your eyes, nose, and mouth are germs’ favorite ways to enter your body. If you want to give your immune system a hand, don’t touch your face.

While it might seem harmless, touching your face transports microbes from your hands to your body. Not all face-touching is sticking your fingers in your mouth. Rubbing your eyes, scratching your nose, biting your fingernails, all of these pesky habits introduce germs to your body.

It won’t be easy, but if you struggle with touching your face, you can break the habit. Try to hold yourself accountable for the sake of your immunity. Paint your fingernails to avoid biting them, and keep your hands occupied to resist rubbing your eyes. Reward yourself when you succeed. Find a family member or friend to remind you when you slip up. And if you have to touch your face, wash your hands first.

Don’t: Smoke

There’s no sugar-coating it—smoking is a dangerous habit that affects your whole body, immune system included.

Smoke from cigarettes destroys the lining of protective epithelial cells lining the inside of your mouth, nose, and throat. You need this layer of cells to safeguard your airway from germs. Smoking also injures lung tissue, which is particularly vulnerable to infection from viruses and bacteria.

Quit smoking as soon as possible to protect your lungs and overall immunity.

Don’t: Drink too Much Alcohol

Binge drinking harms your immune system in similar ways to smoking. Chronic binge drinking damages the cells lining your mouth and throat. It also limits the function of white blood cells—your immune system’s attack force against pathogens.

The proof? Heavy drinking is correlated with being sick more often. So, too much alcohol seems to weaken your immune system and increase your susceptibility to illness.

Cut down on excess drinking to support your immunity. Your body can tolerate moderate, responsible drinking—one drink per day for women, and two per day for men. Just be careful of overdoing it.

Don’t: Forget to Wash Your Hands

Handwashing is the single most effective way to protect yourself from potential pathogens. And it’s an easy habit to adopt. Remember to wash your hands before eating, after using the restroom, and after you visit public places.

But it’s not as simple as rinsing off your hands. Proper handwashing technique takes practice. Visit this handwashing guide to learn how to do it right. And start washing your hands frequently to take some pressure off your immune system and stop the spread of germs to others.

Don’t: Misuse Sanitizers and Disinfectants

Sanitizing, disinfecting, and overall cleanliness will help limit your exposure to germs. Don’t go overboard, though. The products you use to kill germs can also be bad for you if you don’t use them properly.

Never use cleaners, disinfectants, or sanitizers made for surfaces, glass, fabric, or your bathroom on your skin or inside your body. These products range from irritating to toxic. Wear proper protective equipment (like gloves or goggles) while disinfecting areas of your house.

It may seem obvious, but absolutely don’t drink any of these cleaners, use disinfectant sprays on yourself, expose yourself to ultra-harmful UVC sanitizing lights. Ingesting or injecting these into your body could result in a call to poison control or an emergency-room visit.

Hand sanitizer is the exception. They’re designed for use on your skin—and only on your skin. Alcohol-based hand sanitizers (both sprays and rubs) work great for hand hygiene in a pinch. But you should only use them as directed by manufacturer’s instruction. Also make sure to supervise children using hand sanitizers, so they use them properly and effectively.

Don’t: Skip Your Workout

When you choose the couch over exercise, your fitness isn’t the only thing that suffers. Moderate workouts can help maintain a healthy immune system.

Regular exercise is linked to better immune function and fewer bouts with sickness each year. That’s because physical activity improves circulation of blood and the lymphatic fluid that make up your immune system. Aerobic exercise also helps strengthen your lungs, making them more efficient at getting oxygen to your body.

Maintaining consistent workouts helps you build up healthy muscles and joints, while enjoying the added bonus of protecting yourself from sickness.

Don’t: Limit Your Fruits and Veggies

Diet plays a big part in supporting your body’s immune response. Fill your plate with foods that help maintain a healthy immune system. And fruits and vegetable are a great place to start.

Try to eat a fruit or vegetable in every meal. That’s because antioxidants and vitamins are densely packed in tasty fruits like oranges, apples, bananas, and berries. Your body needs antioxidants to help destroy the structures of viruses and bacteria before they can harm healthy cells.

Veggies supply your blood with minerals—like iron and magnesium—and your body with beta-carotene and B vitamins. Each are important nutrients that support immune function. They keep cells healthy so your immune system can focus on hunting down invaders.

Don’t: Miss a Daily Dose of Vitamins

Supplements are a great for supporting your body with vitamins and minerals that help support your immune health. So, make sure you keep taking your multivitamins.

Look for supplements with a good amount of vitamins C, B6, and E. These antioxidants support your immunity and help maintain the health of your tissues and cells from damaging microorganisms. Vitamin C also supports your body’s normal production of white blood cells. They’re the immune cells that find and destroy potential pathogens.

A supplement is a reliable source of quality nutrition your immune system can depend on. Use nutritional supplements in conjunction with a healthy diet to properly support your immunity.

Don’t: Go to Work When You’re Sick

If you have the option to stay home from work when you’re under the weather, take it. This practice doesn’t put others at risk and gives you time to recover.

Think about all the shared spaces and objects you touch in the office. A sneeze or cough leaves droplets with germs behind. Those germs can linger for hours or days on just about any surface. This makes it easy for whatever bug made you sick to spread to a coworker.

Consider the people you work with when you want to tough out a cold and go into work. They will be thankful you stayed home and rested instead of testing their immune systems. You might even find that you recover faster when you take time off to recuperate at home.

Don’t: Let Stress Overwhelm You

It’s best for you and your immunity to slow down and minimize stress. That’s easier said than done. Stress can creep in from work, school, and family responsibilities. And it takes a serious toll on your immune system if not properly managed.

Stress suppresses just about every bodily function, immunity included. When life’s daily tasks pile up, your immune system has to slow down to accommodate. Cortisol (a stress hormone) floods your bloodstream and impacts your immune responses. White-blood-cell production drops off, making you an easier target for a cold or flu virus.

Managing stress is an artform that takes years of practice. But you can start to minimize stress by taking an inventory of your daily responsibilities. Try to remove unnecessary activities that take up time and energy. Learn to say no to assignments you can’t manage. Ask for help when you’re overwhelmed.

Learning to cope with stress will protect your immunity and overall health. Sleep, exercise, meditation, and counseling are other great ways to handle stress. Put your wellbeing ahead of the tasks you have to do so you can reduce stress for a happier, healthier life.

Now Review What to Do for Immune Health

Armed with a list of what NOT to do, now you can focus on building habits that can help support your immune system.

Set a goal to be vigilant about drinking water and washing your hands. Be courteous and stay  home from work when you feel ill. Show your body respect by fueling it with whole fruits and veggies, while saying no to smoking and drinking in excess.

Learn the habits that help support immunity and learn what to avoid. Your lifestyle decisions have the capacity to make a difference in your immune health.