How to Boost Your Immune System: An Expert's Guide
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The immune system is the body’s first line of defense in the war against illness, disease, and injury. It is the body’s alarm system and defense mechanism against viruses, pathogens, bacteria, and other microscopic invaders. The human body becomes susceptible to chronic illness or disease without a healthy immune system.

A robust, healthy functioning immune system is a complex and powerful machine consisting of two parts – the innate and adaptive immune systems – that work together to protect the body. The innate immune system is the body’s first response to invaders.

When the immune system detects a threat – such as a cold virus or wound, the innate immune system sends Natural Attack cells and phagocytes, a type of white blood cells, to contain it. The adaptive immune system assists in eliminating the threat with T-Cells and antibodies that adapt and learn from the illness, ensuring the next time the invader appears in the body, the immune system reacts faster and more efficiently to remove it.

But, not every immune system functions as efficiently or strongly as others. Individuals can suffer weaker immune systems due to autoimmune conditions like arthritis or lupus, hemophelia, malnutrition, and cancer, among other causes. Weakness of the immune system can last a lifetime or absolve completely, depending on the cause. A depressed or compromised immune system will struggle to fight off infection, heal wounds, or adapt to new pathogens.

Though several immunosuppressive factors, such as genetics, cannot be prevented, individuals can take steps to protect and strengthen their immune systems through lifestyle changes. A lifestyle consisting of a healthy, nutrient-dense diet, physical activity, stress management, and adequate sleep can play a pivotal role in strengthening the immune system.

I. Nutrition and the Immune System

I. Nutrition and the Immune System
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According to Oregon State University’s Linus Pauling Institute, malnutrition is the number one immunodeficiency in the world. Many suffer from malnutrition because of a lack of food. However, nutritional deficiency is also a common issue in Western diets. Malnutrition typically stems from three issues: not eating enough nutrient-dense foods, lack of food, and the inability of the body to use nutrients correctly.

Following a healthy, balanced diet helps individuals to avoid and/or address malnutrition – and, as a result, strengthens their immune system. But why does nutrition play such a critical role in the integrity of the immune system?

The Role of Nutrition in the Immune System

The cells of the immune system rely on nutrients to function correctly. Nutrients like Vitamin C, Vitamin D, Zinc, and Protein are critical components to cellular growth for the immune system (and all other cells in the body.) For example, deficiency in Vitamin E and C can reduce white blood cell functioning, resulting in a reduced immune response.

Some nutrients can help improve the immune system’s performance and alter the immune response. According to Harvard University, studies indicate that specific vitamins can work as antioxidants for the body, enhance immune cell growth, and help produce antibodies. Vitamins thought to aid these processes include iron, folic acid, Vitamins A, B6, C, D, and Zinc.

On the Subject of Vitamin Supplements

These days, supplements have become a popular source of immunity-boosting vitamins. However, vitamin and mineral levels are strongest when you get them from consuming food. Remember, human bodies were designed to eat nutrition; vitamins, while helpful, aren’t what the body was designed to consume.

A diet full of whole grains, fresh fruits and vegetables, and lean proteins will provide a dense array of nutrients to fuel the immune system. It’s always best to choose unrefined sources of food when possible – whole wheat bread, fresh peaches versus canned, etc.

Followers of certain diets and lifestyles inherently have fewer nutrient sources. For example:

  • Vegetarian: Vegetarian diets run low on zinc, Vitamin D, calcium, and iron.
  • Lactose-Intolerance: Lactose-free diets can run short of Vitamin D, calcium, and iron.
  • Keto: Keto diets can be low in magnesium, Vitamins A, E, and D.

Individuals who follow dietary restrictions by choice or necessity can supplement their diets with vitamin supplements.

II. Exercise and the Immune System

II. Exercise and the Immune System
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Exercise and the immune system have a tightly-knit relationship. It should come as no surprise, considering whenever dietary changes are recommended to improve health, exercise is almost always recommended alongside it.

Understanding how physical activity helps the immune system requires understanding two components of the immune response – cytokines and chemokines. Cytokines control the growth of immune system cells, and chemokines help direct white blood cells’ fighting and healing response during an infection.

When someone exercises, their body releases cytokines and chemokines. During exercise, the body creates minor inflammation as muscles tear and strengthen under physical duress. This inflammation is the reason for soreness post-workout.

As a result, exercise has a regulatory effect on the immune system. It allows the immune system to run what are essentially test responses to increased inflammation – essentially putting the immune system through its paces and fine-tuning the immune system.

Additionally, exercise plays an accessory role in promoting immune health by reducing stress and improving sleep. Both stress and sleep play an important role in the immune system’s health.

How Often Should Someone Exercise for Immune Health?

The consensus by sleep experts is that just thirty minutes of aerobic exercise a day can help improve immune health and sleep function and reduce stress. Low-impact exercises like swimming, yoga, and walking are excellent physical activity choices that avoid stressing the joints. Running, cycling, and High-Intensity Interval Training are other popular forms of anaerobic exercise.

To create a balanced exercise regimen, consider adding anaerobic exercises like strength training alongside aerobic exercises. Research has shown that weight training can also improve the immune system. The Centers for Disease Control recommends at least two days of anaerobic exercises a week and up to 150 minutes of aerobic exercise a week for optimal health.

Too Much Exercise Can Impact the Immune System

A common mistake many people make when exercising is exercising too much. Over-exercising strains the body. The excess stress put on the body can weaken the immune system, increasing the risk of prolonged injury and illness. Generally, the immune weakness caused by overexercising resolves with rest.

Exercises for the Immune Compromised or Older Populations

Sometimes, rigorous exercise is not an option. Older or immune-compromised individuals should stick to low-impact aerobic exercises like yoga, tai chi, or swimming to help their immune system and overall physical health. Low-impact exercises are less likely to cause injury.

III. Sleep and Immune System

III. Sleep and Immune System
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The body does its most important work when someone sleeps. It provides the body energy for the next day, allows the mind to process new data, and is the prime working time for the immune system.

During sleep, the immune system gets to work. Research indicates that during sleep, the body undergoes a healing inflammatory response via the immune system’s cytokines which work to heal the body during periods of injury or illness. The immune system continues the cytokine work during periods of health as a sort of exercise to continue strengthening the immune system.

Additionally, sleep improves the immune system’s ability to remember and adapt to new threats. The ability to adapt to foreign viruses and bacteria faster and more efficiently is critical to a healthy immune system. Sleep gives the body the energy to fight off infection and the best time to do so.

Sleeping Disorders and the Immune System

The immune system itself impacts how much sleep someone needs. During periods of illness, the immune system will trigger the body to enter longer lengths of stage 3 non-rapid eye movement (NREM) sleep – also known as “deep sleep.” During this stage, the body can heal more rapidly.

If an individual suffers from a depressed immune system, typically, their sleep will suffer, and vice versa. Sleep disorders are a common cause of lack of sleep or sleep deprivation. Common sleep disorders include sleep apnea, insomnia, and circadian rhythm disorders.

How Sleep Deprivation Impacts the Immune System

According to the CDC, one in three adults doesn’t get enough sleep. That’s a significant problem, considering that sleep deprivation can drastically reduce immune function in an individual. Studies indicate that lack of sleep reduces the natural killer cells used by the immune system to fight infections by about 25% and increases the production of inflammatory cells in the body.

In the long run, sleep deprivation can lead to chronic illness, heart disease, and an increased risk of infections.

How Much Sleep Does the Immune System Need?

The immune-suppressing effects of sleep deprivation typically occur in individuals getting less than six hours of sleep a night. According to the CDC, the general recommendation for a “healthy” amount of sleep is seven or more hours for an adult.

5 Tips for Getting More Sleep

Sometimes, falling asleep seems impossible. Unfortunately, everyone at some point in their life will struggle with bouts of insomnia. The important thing is to address it before poor sleep becomes a chronic issue. Individuals suffering from lack of sleep can try following these tips for a better night’s sleep:

    • Follow a bedtime schedule. By setting a designated bedtime, the body becomes trained to fall asleep around a designated time.
    • Implement winding-down time. Giving the body a chance to relax and prepare for rest can help individuals fall asleep faster.
    • Practice mindfulness, meditation, or journaling before bed. Research indicates that similar self-care practices can promote relaxation and healthy sleep.
    • Avoid blue light from television, phones, and computers two to three hours before bed. Blue light suppresses melatonin production in the body – the hormone that helps individuals fall asleep naturally.
    • Sleep in a colder room. Studies indicate that sleeping in a room set at 65 degrees can improve sleep by helping the body regulate its temperature during sleep.

IV. Stress and Immune System

IV. Stress and Immune System
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Perhaps one of the most powerful factors that impact the immune system is stress. Stress is a natural part of life, and in some cases, it can improve the immune system – as is the case with bodily stress caused by exercise. But, excess stress can dampen the body’s immune response and weaken the immune system considerably.

How Stress Weakens the Immune System

Psychological and physical stress can wreak havoc on the body’s immune system. For example, excess stress can reduce the production of white blood cells in the body, which is key to fighting off infections due to an increase in the stress hormone cortisol.

In a healthy body experiencing normal levels of stress, cortisol plays an important role in controlling the body’s metabolism. But in an overly stressed body, cortisol can hamper the body’s natural anti-inflammatory response. Additionally, prolonged periods of stress can result in extreme levels of inflammation in the body, increasing the risk of chronic or prolonged bouts of illness or disease.

Common Sources of Stress and Their Impact on the Immune System

Humans experience countless sources of stress in their day-to-day lives. But, nearly all forms of stress fall under one of three types – acute, episodic acute, and chronic stress. All three forms of stress can impact the immune system.

Acute Stress

Acute stress is the most common and least impactful form of stress. It is an immediate reaction to new, stressful stimuli. Most instances of acute stress trigger a physical feeling of excitement or hyperactivity. Acute stress can come from something entertaining, like the drop on a roller coaster, or something seemingly minor, like the rush of being late to work. It is a momentary period of stress that resolves after the stimuli are removed.

Usually, acute stress does not dramatically impact the immune system. However, one type of acute stress can put the immune system through the wringer. Severe acute stress happens during a life-threatening situation, such as a car accident, and can lead to Post-Traumatic Stress Disorder. Research indicates that PTSD sufferers can also suffer from increased inflammation caused by the immune system.

Episodic Acute Stress

Episodic acute stress occurs when an individual suffers from repeated periods of acute stress. Episodic stress usually manifests during periods of constant anxiety or high-stress situations. Individuals in law enforcement or emergency services are particularly at risk for episodic acute stress. Unfortunately, individuals suffering episodic stress often experience a weakened immune system as cortisol levels remain constantly heightened.

Chronic Stress

The worst type of stress on the immune system is chronic stress. Chronic stress is, essentially, a state of long-term, heightened stress response. Individuals suffering from chronic stress will likewise suffer from a weakened immune system as the perpetual cycle of high cortisol takes its toll on the body. Chronic stress can occur for many reasons, not the least of which are anxiety disorders, poor work-life balance, and relationship troubles.

5 Tips to Managing and Reducing Stress

Not only does reducing and managing stress levels improve quality of life, but it also helps protect the immune system. Here are a few tips to help manage stress:

  • Practice self-care. Set aside time to do something you like that brings you joy.
  • Focus on getting enough sleep. During sleep, the body processes the stress of the day. Additionally, rest gives the body energy to handle stress during waking hours.
  • Exercise regularly. Studies show that exercising for thirty minutes can reduce stress and help boost the immune system.
  • Connect with Family and Friends. Social interaction provides distraction, laughter, and provide support to get you through stressful times.
  • Set work-life boundaries. It’s important to set boundaries for yourself – keep work at work, home at home. Mixing the two can lead individuals to feel overwhelmed and like they are constantly working. When you aren’t on the clock, mentally disconnect yourself from work and take time to reconnect with home.
  • Practice relaxation techniques. Meditation, yoga, tai chi, and deep breathing exercises have for hundreds of years been practiced as a method for relaxation and body discipline.

Can Relaxation Practices Actually Help the Immune System?

Relaxation techniques like yoga, meditation, and deep breathing can actually improve the immune system. Studies show that yoga and mindfulness meditation actually reduce inflammation in the body. Deep breathing, which also plays a role in yoga and meditation, can stimulate the parasympathetic nervous system and promote a physical sense of calm – thus reducing stress, which benefits the immune system.

V. Other Ways to Boost Immune System

V. Other Ways to Boost Immune System
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Aside from nutrition, exercise, sleep, and stress, there are other steps an individual can take to boost their immune system. A good rule of thumb is to eliminate practices that harm the body – physically and mentally – because if the body takes damage, the immune system does too.

Change Lifestyle Practices

Smoking, alcohol consumption, and eating added sugar are three lifestyle practices that, when eliminated, can boost the immune system.

Refined Sugars 

Added sugars like corn syrup and dextrose have an inflammatory effect on the body. They also contribute to chronic diseases like heart disease and diabetes, which can impact the immune system.

Smoking and Alcohol Consumption

Both smoking and excess alcohol consumption can damage the body. Cancer, high blood pressure, and lung and liver damage are just a few consequences of smoking and drinking. The effects of these substances can weaken the immune system and force the immune system into overworking itself.

Drink More Water

Water plays an important role in immunity – without water, white blood cells can’t circulate through the body.

Avoid Exposure to Harmful Substances 

Illicit drugs, chemicals, and pollution can all reduce the integrity of the immune system, especially with prolonged exposure. Avoiding exposure to harmful substances can help protect the immune system.

Stay Up to Date on Vaccines

Vaccines expose the body to an inactive virus or organism, triggering an immune response. The body learns to fend off that illness, preparing it to react quickly and efficiently during an actual infection.

Consider Immune Supporting Supplements

Some proponents of supplements claim to help support the immune system, including echinacea, elderberry, and lion’s mane mushrooms. Herbal supplement companies say their supplements can help improve and protect the immune system. The supplements usually include some variation of zinc, Vitamin C, probiotics, Vitamin D, and probiotics.

Individuals lacking certain vitamins should consider taking supplements to fill in the gaps. However, it’s important to remember that supplements featuring herbal remedies don’t undergo FDA testing for efficacy. Studies are limited on the effectiveness of herbal supplements in helping the immune system.

Additionally, it’s important to ask a medical professional about the interaction any herbal supplement may have with the medications or conditions of an individual. It’s not uncommon for supplement users to find they are allergic to some ingredients in herbal supplements. Watch for allergic responses like an itchy throat, runny nose, red eyes, or swelling of the throat after taking a new supplement.


  • Does Fast Food Harm the Immune System?

Experts agree that research points to fast food having a damaging effect on the immune system if consumed too often. The reason is simple – fast food usually contains high levels of sodium that trigger heightened inflammation and increased immune response in the body.

  • Can Obesity Impact the Immune System?

Yes, obesity can impact the immune system. Obesity can cause chronic, low-grade inflammation, which wears down the immune system.

  • Do Probiotics Help the Immune System?

Yes, research indicates that probiotics can benefit the immune system. Probiotics improve gut health, and the immune system produces antimicrobial proteins in the gut. Thus, a healthy gut keeps the immune system healthier.

  • How Do You Know If You’ve Over-Exercised?

Symptoms of over-exercising include lower performance, feeling tired, and the appearance of overuse injuries like tendonitis or sprains.

  • Is It Better to Get Vitamins from Food or Supplements?

It is always better to get vitamins directly from food whenever possible. Vitamins cannot replace food – the body needs all the nutrients, and fuel food provides to keep the immune system energized and functioning. Therefore, vitamins are best used as supplemental to a healthy diet.

  • How Much Alcohol Is Safe for the Immune System?

Generally, individuals should always drink in moderation. The CDC defines “moderate drinking” as two drinks a day for men and one for women.

  • Can Lack Sleep Make You Sick?

Yes, lack of sleep can contribute to an individual getting sick more frequently. Lack of sleep weakens the immune system, making it harder for the body to fight infections.


The immune system is a powerful and complex system that protects the human body from illness, disease, and injury. However, as powerful as it is, the immune system can be weakened by factors like lack of sleep, poor nutrition, stress, and lifestyle choices.

But, individuals can take steps to improve their immune systems. By prioritizing healthy practices like getting enough sleep, eating nutritious foods, exercising regularly, and reducing stress, you can boost the immune system. Ultimately, following practices that boost the immune system will give you an overall sense of well-being and a better quality of life.


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