How do you strengthen your immune system? It comes down to what you eat and what you don’t eat, but also what you do and what you don’t do.

Your immune system usually does a good job of protecting the rest of your body from disease-causing microorganisms. But it can fail just like any other system.

Improving your immune system is more complicated than taking a vitamin or supplement. As Harvard Health explains, “The idea of boosting your immunity is enticing, but the ability to do so has proved elusive for several reasons. The immune system is precisely that — a system, not a single entity. To function well, it requires balance and harmony.”

So, if the immune system is such a complex system, how can we improve its function?

As researchers continue to study the immune system, they’ve uncovered strong correlations between lifestyle and immune function.

They continue to explore the impact of diet, exercise, age, stress, and other factors on the immune response.

7 Thing That Impair Your Immune System and 8 Things That Boost It.png

7 things that compromise your immune system

Maintaining a healthy lifestyle is one of the most effective ways to support your immune system. So, let’s take a look at the specific things that compromise your immune system.

1. Stress

A stress-free life seems like a luxury. We have responsibilities, so how are you supposed to eliminate stress. There are two types of stress: long term stress and short term stress. Long term stress, like the stress of a job, has proven harmful for your immune system.

As Robert Morris Sapolsky wrote in his book, Why Zebras Don’t Get Ulcers, “Stress-related disease emerges, predominantly, out of the fact that we so often activate a physiological system that has evolved for responding to acute physical emergencies, but we turn it on for months on end, worrying about mortgages, relationships, and promotions.”

2. Lack of sleep

Research has shown that your sleep, or lack of it, impacts your immune system. As one study notes, “Sleep and the circadian system are strong regulators of immunological processes.”

3. Sickness

It might sound like circular reasoning to list “sickness” as a cause of impaired immune function. But the reason I mention it is because sickness can make you vulnerable to the attacks of other germs and viruses. Your immune system can come out the other side of sickness more susceptible to other illnesses.

4. Alcohol

Most research studying the impact of alcohol consumption on the immune system involves heavy drinking. But research does suggest that even moderate alcohol consumption can impair the communication between cells which can directly compromise immune function.

5. Junk food

It might sound like common sense, but let’s ask the question:

Does junk food affect your immune system?

And of course, the answer is yes. But it’s not as directly related as you might think. Consuming junk foods impairs your body’s immune system in a couple of ways.

Eating “healthy” can be a misleading. Image provided by NutritionFacts.org.

First, it starves your body’s microbiome. Secondly, consuming junk food crowds out whole foods you could otherwise be eating.

6. Age

Unfortunately, there’s not much you can do about your next birthday. As you age your body’s immune system begins to get a little weaker.

A study published in 2013 noted, “The effects of aging on the immune system are manifest at multiple levels that include reduced production of B and T cells in the bone marrow and thymus and diminished function of mature lymphocytes in secondary lymphoid tissues. As a result, elderly individuals do not respond to immune challenge as robustly as the young.”

7. Smoking

You’re probably not surprised to read that smoking also impairs your immune system. Cigarette smoke suppresses cell function and compromises pathogen killing cells that play an important role in your body’s ability to fight off disease.

Bonus: Does cold weather weaken your immune system?

You probably remember your mother telling you to “Wear a coat or you’ll catch a cold!”

If Wim Hof isn’t proof that this is a myth, I don’t know what is. The man has literally climbed Mount Everest in his shorts!

So far, researchers who are studying this question think that normal exposure to moderate cold doesn't increase your susceptibility to infection. Most health experts agree that the reason winter is "cold and flu season" is not that people are cold, but that they spend more time indoors, in closer contact with other people who can pass on their germs.

7 things that protect your immune system

Now that we know what weakens your immune system, let’s take a look at 7 things that will strengthen it.

1. Exercise

Regular exercise is an important part of your health for several reasons. It improves cardiovascular health, lowers blood pressure, helps control body weight, and protects against a variety of diseases.

Just like a healthy diet, exercise can contribute to general good health and therefore to a healthy immune system. It may contribute even more directly by promoting good circulation, which allows the cells and substances of the immune system to move through the body freely and do their job efficiently.

How to exercise: Start where you are. Make a habit of moving more. If you’re not exercising at all, then start by taking a 20-minute walk 3-5 days each week.

2. Lower stress levels

I’m sure you’ve heard that stress isn’t great for your immune system. But why?

The simple answer is that stress interferes with both your endocrine system and your central nervous system (CNS).

The endocrine system is the chemical messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system. And the central nervous system (CNS) is the nerve tissues that control the activities of the body.

There’s a lot of research in regards to what stress does to our immune function. But one study summarizes the impact of stress on these systems by explaining, “stress can induce immune dysregulation across many aspects of the humoral and cellular immune responses.”

Simply stated: stress interferes with your body’s endocrine and central nervous systems’ ability to communicate.

How to lower stress levels: Take an inventory of your life. Identify what’s causing the most stress in your life. Maybe there’s something you need to change or eliminate in your life to lower your stress levels.

3. Eliminate or decrease alcohol consumption

Alcohol disrupts your body’s immune functions making you more susceptible to many different viruses. In addition to impairing your body’s ability to fight off illness, alcohol consumption has been shown to accelerate certain diseases.

How to decrease alcohol consumption: Alcohol consumption is often associated with habits. Where are you going after work? Who are you spending the most time with? Just like with stress, you may need to change something to decrease your alcohol consumption. Maybe that means not joining your coworkers for happy hour after work. Or maybe instead of going out every night you only go out one night on the weekend.

4. Reduce inflammation

You might be asking, “Isn’t inflammation our body’s way of healing itself?”

Yes, acute inflammation is our immune system’s response to damaged cells, irritants, and pathogens that contact the skin. However, chronic inflammation takes place underneath your skin and affects your organs.

Chronic inflammation symptoms include:

fatigue
mouth sores
chest pain
abdominal pain
fever
rash
joint pain

Chronic inflammation can be caused by viruses and even the food we eat such as refined carbs, sugary beverages, red meat, and other animal-based foods.

How to reduce inflammation: The best way to reduce chronic inflammation is by improving your nutrition. Start by adding more whole plant-based foods to your meals.

5. Get adequate sleep each night

As we previously read, inflammation impairs your body’s ability to fight off infection. Sleep loss is strongly associated with inflammation. Your body uses sleep to repair itself and fight off infection.

How to get adequate sleep each night: Too few of us get enough sleep each night. I get it – it can be difficult. At the end of a long day or after you’ve finally got the kids to bed you just want some time to yourself. Maybe that means a couple of hours binge-watching your favorites series. Unfortunately, this cycle affects the following day.

Aim for 7-8 hours of sleep each night. Yes, this might mean your Netflix viewing will suffer. But you’ll be better for it the next day.

6. Strengthen your gut bacteria

More than 2,500 years ago Hippocrates said that “All disease begins in the gut.” Today, we realize that statement still holds true.

Your gut flora promotes intestinal health by decreasing gut inflammation and increasing the good bacteria in your stomach. As a result, this decreases the bad bacteria in your stomach and helps your body fight off sickness and disease.

How to strengthen your gut bacteria: The easiest way to improve your gut bacteria is to begin by taking a probiotic. Then focus on consuming more whole plant-based foods.

7. Eat a healthy diet

Eating whole, plant-based foods is one of the best ways to feed your gut bacteria and boost your immune system. Animal-based foods have been shown to diminish your gut flora and increase the bad gut bacteria.

On average, Americans don’t consume enough healthy foods. Image provided by NutritionFacts.org.

There are a few specific foods that go beyond feeding your gut bacteria to help strengthen your immune system.

How to eat healthy: The easiest way to strengthen your immune system is to focus on eating more whole plant-based foods and incorporate the following six mentioned foods.

Foods that are good for your immune system

We often think of vitamin C when it comes to improving immune function. Yes, eating fruit high in vitamin C is a great way to strengthen your immune system. But there are many other foods and vitamins that you should consider.

It really is true: One added apple a day really can help keep the doctor away. What we eat (or don't eat) affects our immune system.

Cruciferous vegetables

We can lower inflammation with cruciferous vegetables: cabbage, broccoli, cauliflower, kale, brussels sprouts.

Those who eat more fruits and vegetables are least likely to get an upper respiratory tract infection like the common cold or influenza.

Nutritional yeast

Stressful life events can impair our moist membrane defenses, such that “psychological stress [has also] been shown to increase susceptibility to the common cold,” getting more colds, and worse colds, than people under less stress. So, let’s see if we can help. Indeed, in this study of healthy women under moderate levels of perceived psychological stress, those taking about a teaspoon of nutritional yeast a day worth of beta-glucans for 12 weeks were 60% less likely to report experiencing symptoms, like sore throat, stuffed or runny nose, or cough—strongly suggesting that baker’s, brewer’s, and nutritional yeast “beta-glucan is able to counteract the negative effects of stress on the immune system.” And, they experienced 41% greater vigor (which is a measure that encompasses “physical energy, mental acuity, and emotional well-being”). So, they just felt better, too.

Put all the studies together, and yeast beta-glucans do appear to have immune-strengthening effects, at least in children, and those under physical or mental stress.

Green tea

We’ve known that green tea to be an antiviral remedy for thousands of years. In more recent applications, healthcare workers given green tea came down with the flu three times less than those who weren’t given green tea.

The benefits of drinking tea highlighted by Dr. Greger. Image provided by NutritionFacts.org.

Green tea boosts your body’s T-cell production acting as another barrier of defense against viruses.

Kale

Just a slight pump in kale increases your body’s antibody production.

Garlic

Garlic stimulates immunity, suppresses inflammation and boosts immunity. Eating garlic can lead to fewer colds, reduced severity of symptoms, and faster recovery.

Eating raw garlic is the best. However, don’t put it on your skin as it causes a burn.

Turmeric

Turmeric has been shown to be the single most anti-inflammatory food. Consuming just a 1/2 tsp a day decreases inflammation.

Summary

If you want to boost your immune system, try avoiding the seven things that compromise it and focus on doing and consuming the eight things that boost your immune system.

7 Things That Impair Your Immune System and 7 Things That Boost It