There are very few things in the world worse than being stuck in bed because you’re sick. The CDC estimates that seasonal influenza caused U.S. employees to miss approximately 17 million workdays. That’s a staggering $7 billion in sick days and lost productivity! For some people, the symptoms of the common cold seems to linger for weeks. While other people never get sick. All things being equal, the difference usually comes down to a strong immune system.

Once a virus enters your system, your body goes into defense mode, with your immune system in the front line. What’s amazing is that, unless something is wrong with your body’s system of defense, you don’t notice it working day and night to keep you safe. It has evolved over many years to protect you and keep you strong and healthy, which is a rather comforting feeling. Beyond gratitude, there are things you can do to help boost your immune system. After all, as strong as he was, Batman wouldn’t be able to save Gotham City without the help of Robin.

The Human Immune System

The Immune System is very complex and essential in maintaining health. Its main tasks are to neutralize pathogenic microorganisms like bacteria that enter the body and threaten its normal homeostasis, eliminate harmful substances from the environment, and fight against the body’s own cells that rebel and cause illnesses like cancer.  

Your body’s defense system consists of the innate and adaptive immune processes. Elements of the innate system include exterior defenses, such as the skin, serum proteins, and phagocytic leukocytes. Any pathogenic organisms that manage to escape the first line of defense, come face to face with the adaptive system, which is made up of T and B cells. The adaptive immune system serves as a learned defense, constantly adapting and evolving in order to be able to identify changes in pathogens that, too, change over time. It’s an evolutionary arms race between host and pathogen. Together, the innate and adaptive systems work closely to provide a formidable resistance to any long-term survival of infectious agents in the body.

Mighty as it may be on its own, there are simple adjustments you can do in your everyday life to help strengthen and boost this magnificent, genius system that’s working to keep you safe.

Ways to boost your immune system

1. Quit Smoking

You don’t need anyone to tell you that smoking is bad for your health.  Smoking impairs the immune system and is associated with a long list of cardiovascular, autoimmune, respiratory and neurological diseases. The list of common symptoms of tobacco-related diseases includes shortness of breath, persistent cough, and frequent colds or upper respiratory infections.

Specifically, the substances you ingest while smoking a cigarette have a direct effect on both the innate and adaptive immunity, suppressing the normal development and function of the cells that are responsible for driving immunity in the body. Nicotine, in particular, has been shown to be a potent immunosuppressive agent by affecting the immunosurveillance properties of dendritic cells, highly-specialized cells of the immune system.

Imagine this; your body fights for your survival every single day of your life, and in the meantime, you can be counteracting these efforts every time you decide to smoke. Is that cigarette worth your health?

2. Drink Alcohol in Moderation

Alcohol is often associated with celebrations and anniversaries, but if you abuse it, your immune system suffers.  Alcohol consumption is a contributing factor to organ damage, specifically the liver, and is known to slow down recovery from tissue injuries. The “Dietary Guidelines for Americans” defines moderate drinking as up to 1 drink per day for women and up to 2 drinks per day for men.  Alcohol intake exceeding the recommended intake disrupts essential immune pathways and, in turn, impairs the body’s ability to defend itself against infections.  

It is worth stating that alcohol-related immune system disturbances have been implicated in the development of certain types of cancer, including but not limited to head and neck cancers among alcohol users. Before you start thinking that this is a problem isolated to chronic alcohol users, keep in mind that acute binge drinking, also known as a Saturday night, has the ability to severely impair the body’s defense system.

3. Keep the Stress Away

Chronic stress is like poison for your body; it has a negative impact on every aspect of your health, and it’s even more dangerous due to its ability to creep up without you consciously acknowledging it.  One of the many systems responsible in the body for handling difficult situations is the immune system. Specifically, cells of the immune systems are equipped with receptors that recognize stress hormones, such as cortisol.  

Even acute stress can mess up your immune system by increasing the release of inflammatory-promoting cytokines in the blood, a special type of immune cell that signals other cells and affect their function. Stress, immunity, and disease can affect each other in reciprocal ways, but these relationships can be moderated by life stage, other environmental pressures and goals, stressor duration, and protective factors, such as good sleep. Make sure you have a healthy strategy to help you relieve the symptoms of stress like exercising or spending time with friends and family. 

4. Get More Sleep

Speaking of sleep, it is a strong regulator of immunological processes and works to enhance the memory of the adaptive immune system. When you deprive your body of adequate sleep, you simultaneously make it more susceptible to many infectious agents. Sleep deprivation not only makes you more susceptible to infections like the common cold or the flu, but it also makes it so much harder to recover from the bacteria or virus infection that eventually manages to enter your system.  

While you are sleeping every night, your body uses this time to strengthen the immune system and move T cells to the lymph nodes, the vessels of the immune system responsible for filtering harmful substances. These T cells produce cytokines which are called to action when there is inflammation in your body or when you’re under stress. During periods of inadequate sleep, cytokine production is diminished, further hurting your immune system.  So feel free to hit that snooze button, and in case you come down with the flu, feel free to hibernate for a few days.

5. Exercise Regularly – But Don’t Skip Rest Days

Most people have a love-hate relationship with exercise.  This particular argument will only add to your love towards exercise. Studies have proved that regular physical activity may enhance the immune system and provide protection against infection.

Furthermore, regular resistance exercise increases your muscle mass, which acts as a protein reserve when the immune system is working to stave off disease. Simply put, the more muscle mass you build through a healthy diet and regular exercise, the more equipped your body is to fight off infection and keep you strong and healthy. Conversely, getting rid of bacteria or virus infection will be a lot harder if you have been neglecting the gym.

But don’t forget to take your workouts outside. Exercising outside is a great way to both destress and reap the benefits of Vitamin D. Vitamin D deficiency has also been linked to an increased susceptibility to infection, so when the weather permits try to go outside and enjoy the sun.

Unfortunately, no one can stay young forever, and as the body ages, its natural defenses begin to waiver.  The good news is that regular physical activity in the elderly may counteract the actions of time and boost the immune system so that it can protect the body from infection and disease.

Nonetheless, like everything else in life, too much of a good thing can be bad.  Being a couch potato suppresses the immune system, but the opposite extreme can be equally detrimental. Repeated bouts of strenuous exercise, also known as overtraining syndrome, can lead to symptoms like immune dysfunction, so make sure to maintain a healthy balance between regular physical activity and exhaustion.

6. Eat Enough Nutritious Foods

Every system in the body requires energy to function properly. This energy is provided by food sources in the form of calories. Indeed, insufficient intake of calories may lead to micronutrient deficiencies and suppress the immune system and its vital functions. In fact, malnutrition is the most prevalent cause of immunodeficiency around the world.  

Food is powerful; it has the potential to make or break every chemical pathway in the body that sustains you. Because of that, it makes sense that the healthier your food choices are, the stronger your immune system and, subsequently, your health will be.  

Certain nutrient deficiencies have the potential to alter immune responses and damage the way your immune response to infections. Vitamins and nutrients with antioxidant properties can provide protection against free radicals. Adding an abundance of foods high in naturally occurring antioxidants like citrus fruits in your diet is the key to maintaining a healthy immune system. Exposure to environmental conditions such as UV light, cigarette smoke can ultimately take its toll on the immune system and drive the production of free radicals in the body. Antioxidants fight the free radicals and restore the structural integrity of cells and membranes in the body. Examples of such antioxidants include zinc, selenium, iron, copper, vitamin C, A, and E. Foods high in vitamin C, A, and E, in particular, may also increase the activation of cells involved in tumor immunity.

Plant-derived bioactive compounds, known as phytonutrients, also play an important role in strengthening the immune system.  Polyphenols, flavonoids, isoflavonoids, carotenoids, and phytoestrogens, are some of the few phytonutrients that have the ability to enhance the immune system with their immunity-boosting superpowers. Dietary intake of phytochemicals promotes health benefits and protects against chronic disorders, such as cancer, cardiovascular and neurodegenerative diseases, diabetes, and inflammation. Also, their natural origin poses lower side effects when compared to chemotherapy or radiotherapy, and promises a brilliant future for their use in treating specific types of cancer.  

Finally, there is emerging research linking gut health to the immune system and there is promising research highlighting the benefits of probiotics supplementation in improving the body’s response to bacterial infections.

Balanced nutrition, especially in terms of adequate vitamin, mineral and protein intake (for those essential amino acids), enhances the resistance against infections. If you are not sure that you can provide everything your body needs through your diet alone, it might be worth investing in a quality multivitamin to help cover any inconsistencies from your diet. 

7. Maintain a healthy body fat percentage

It has been observed that overnutrition can potentially increase the risk of inflammatory and autoimmune diseases.  A healthy body fat percentage ranges between 10-20% of the total body weight for men and 18-28% for women. Therefore, a percent body fat higher than this may impair the immune response.

Studies have shown that the link between obesity, insulin resistance, and diabetes could be explained through the subsequent activation of the innate immune system.  The same system that is implicated in the pathophysiology of obesity-related liver damage.  A healthy immune system does an excellent job in protecting you from disease, but permanent activation causes the release of immune cells that promote inflammation in the body, making it a lot harder for the immune system to concentrate on its primary goal; to keep you healthy.  

The solution is simple in this case. You can reverse the negative effects of a high body percentage by improving your body composition. Less body fat, specifically visceral fat, equals less immune cells circulating in the bloodstream, promoting inflammation and wreaking havoc on the natural processes of the body.  

In addition to losing fat, gaining more muscle mass, as we spoke about before, can further improve body composition and reset a dysfunctioning immune system, laying the foundations towards long term health.

Putting it All Together

Your immune system works day and night to keep you healthy and often has to fight you in its efforts to maintain normal homeostasis. You can become its best friend by applying these 7 small changes in your everyday life:

1. Quit smoking

2. Drink alcohol in moderation

3. Try to keep the stress away

4. Get enough sleep

5. Exercise regularly, but avoid overtraining

6. Eat enough calories and include foods rich in antioxidants in your diet

7. Maintain a healthy body fat percentage through diet and exercise

You may read this article and think that all these are just too much change for you. Small changes are still a step in the right direction. Change your habits one at a time to help support your immune system, and it will help you bounce back quickly next time you catch a common cold. After all, a strong, healthy body depends on your daily decisions.

Take care of your body, so that it can take care of you.  

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Rafaela Michailidou is a Biomedical scientist, and a freelance health and wellness content writer. Aspiring to help people achieve their goals, she is currently studying to be a Health Coach. 

Editor’s Note: This post was updated on October 4, 2018, for accuracy and comprehensiveness. It was originally published on May 5, 2018

If there’s one thing everyone can agree on, it’s that no one likes being sick.

What if there was something you could do to improve your health and reduce your sick days?

As it turns out, having a healthy body composition contributes to a stronger immune system, helping you to resist minor infections and reduce your risk of getting serious diseases, like heart disease and diabetes.

What’s a healthy body composition? Put simply, there are two main areas of focus: sufficiently developed muscle mass and a body fat percentage in a healthy range  (10-20% for men; 18-28% for women).

Unfortunately, over ⅔ of Americans are classified as overweight, with a shocking 1/3 of Americans classified as obese . Americans are on average heavier than any other time in history. There has been a similar increase in heart disease and diabetes diagnoses. That is why the CDC says obesity is an epidemic in this country.

How does this tie back into the immune system and your health? It all has to do with the nature of body fat.

What Happens When Your Immune System Activates

When your body gets sick – due to a bacterial infection, a virus, etc. – the body’s defense system gets triggered, causing inflammation.  This is thanks to your “innate” immune response: your body’s all-purpose defense mechanism that serves as the first wave of defense against foreign invaders.

The infected area becomes red and swollen due to increased blood flow, which can be unsightly and uncomfortable. Think of what happens to your nose when you get a cold. That’s inflammation.

This reaction is caused by white blood cells called macrophages and the proteins they emit called cytokines (this word will be important in a minute). These cytokines encourage inflammation.

You may have not thought of it this way before, but inflammation that’s triggered by your immune system is typically a good thing. That means your body is releasing the appropriate hormones and proteins, activating your white blood cells to start the recovery process, and working to defeat the infection.  If there wasn’t any inflammation, your body would be in serious trouble.

So if inflammation is what naturally occurs when your body’s immune system is triggered, how does inflammation relate to body fat, body composition, and obesity?

When Inflammation Becomes Permanent

When white blood cells cause inflammation, it’s a sign that your body’s immune system is properly functioning. Inflammation begins, white blood cells attack the foreign invader, the invader is neutralized, and the inflammation subsides.

This is how your body’s defense system naturally works. However, white blood cells aren’t the only type of cell that have the ability to emit cytokines.  A second type of cell that can emit cytokines and cause inflammation are adipocytes or fat cells.

Most people know that your body stores excess calories as fat so that you can use it later for energy if food becomes scarce.  

Just recently, scientists have learned that fat is an active endocrine organ, one that can secrete a whole host of proteins and chemicals, including inflammatory cytokines.

What happens when your body keeps adding on more and more adipose tissue?  Cytokines are released by your fat cells, triggering inflammation. In fact, obesity is characterized by researchers as “ a state of low-grade, chronic inflammation.”

This means that increased fat cells puts your body in a constant state of stress/immune response. Your body is always in a state of inflammation; your immune system is permanently “switched on.”

Think of your body’s immune system like your body’s crack team of defenders, highly trained and designed to repel any and all foreign invaders.  In this scenario, your adipose cells are like enemy agents planted in your home territory. Their mission is to spread fear of an attack at all times, and they trick your defenders to be on high alert at all times.

As you might have guessed, perpetual, never-ending inflammation isn’t good for the body.

Sabotaged Immune System

Obesity causes a state of chronic inflammation, and this causes your immune system to become compromised.  Chronic inflammation is a serious issue and can lead to the development of minor and serious illness and conditions.  Here are a couple examples:

• Influenza (the flu)

You may remember several years ago that there was a particularly deadly strain of the flu virus called H1N1.  As hospitals started to fill up with the sick, doctors in Spain noticed something: overweight and obese patients were beginning to show up in disproportionate numbers in intensive care units, and they were staying for longer than people who were not obese or overweight. Increased inflammation due to increased pro-inflammatory cytokines appeared to be a leading factor contributing to their increased flu risk.

Stories like these led  researchers in Canada to analyze the flu records for the previous 12 years, stretching from 2008 back to 1996. They found that people who were obese were more likely to come into the hospital for respiratory diseases than those who were not obese. They concluded that obese people were an “at risk” population during flu seasons due to their compromised immune response.

• Heart Disease

Heart disease is the leading killer of adults in the United States.  Although there are many factors that can contribute to heart disease, recent research has pointed to inflammation caused by obesity as one of the most significant factors contributing to its development.

The main culprits are, again, the cytokines produced by excess fat in the body.  These cytokines cause inflammation of the walls of your arteries, causing damage to the arteries and increasing pressure. Blood pressure is the force of blood pushing against the walls of your blood vessels. When you have high blood pressure, it means that your heart isn’t pumping blood effectively, and it starts to enlarge. An enlarged heart is a significant risk factor that can lead to heart failure if steps aren’t taken to remedy it.

• Diabetes

Diabetes is a condition characterized by insulin resistance – the inability of your body to remove excess sugar from your blood. Just like heart disease, there are many related factors that lead to the onset of type 2 diabetes, and obesity has long been associated with the development of diabetes.

However, with the discovery that fat is an active tissue that can secrete cytokines and wreak havoc on the immune system, researchers have been able to show a link between obesity, inflammation, and insulin resistance. Increased inflammation was shown to disturb a whole host of processes and the endocrine system. When obesity and the subsequent inflammation is left unchecked for a long time, it increases the risk of developing insulin resistance, and eventually diabetes.

Who’s At Risk?

A compromised immune system and inflammation aren’t issues that only concern overweight people.

Many people know that being overweight and obese is unhealthy and can lead to serious diseases over time.  Admittedly, poor diet and low levels of activity contributing to heart disease and diabetes over time in obese people isn’t exactly news.

Unless you start to take into account what the word “obese” actually means.

Classically, obesity has been defined by having a high Body Mass Index (BMI), a way of expressing the relationship of your weight vs. your height.  If your BMI exceeds 25, you’re labeled “overweight,” and once your BMI increases beyond 30, you progress into different levels of obesity.

Doctors have used BMI for obesity assessment for years, but unfortunately, BMI has led to confusion by inappropriately labeling people as obese or overweight when they are not, or healthy when they should be aware of their obesity risks.

Obesity doesn’t always simply mean “fat.” What obesity does mean is the excess accumulation of body fat, but what’s excess for you might not be for someone else. It is possible to have a “normal” BMI but a lot of excess fat; this is called being “skinny fat.”  Crucially, skinny fat people share many of the same metabolic risks as people who have high BMIs, including the risk of inflammation and a faulty immune system.

This is why you should look at having too much body fat not only as a problem for people who are visibly overweight, but also for people who don’t have enough muscle relative to how much body fat they have.

One way to determine whether you’re at risk is to have your body composition analyzed.  This assessment method will reveal your body fat percentage, a number that you can use to understand if the amount of fat you have is healthy or excessive for someone of your size.

How To Get Your Immune System Back In Line

Fortunately, because researchers have been able to identify body fat (and particularly, internal visceral fat)  as a major cause of inflammation and a compromised immune system, they’ve also been able to measure improvements when body fat is reduced. The goal to getting your immune system to function properly again is to stop it from being perpetually triggered.

In a study that followed obese patients who lost weight with caloric restriction and bariatric surgery, the researchers observed a significant reduction in immune system activation, which means less inflammation.  This reduction in immune activation occurred before and after surgery, which indicates that surgery isn’t always necessary: just the reduction of fat mass – and specifically, visceral fat.

Improving your body composition through a mix of strategies that promote fat loss and muscle gain can allow you to reduce your fat mass in a healthy manner that doesn’t require drastic measures like bariatric surgery.  Although this process can and will take time, the effects of having an improved and healthy body composition are immense, not the least of which is reducing overall body inflammation and having your immune system function properly again.

Healthy Immune System, Healthy Life

We’ve gone over a lot of very technical stuff here, so let’s go over the main points for you to take away.

• Excess Body fat sabotages your immune system by leaving it permanently triggered

• Inflammation caused by body fat makes you sicker and more vulnerable to disease

• You can reduce and reverse these changes by reducing your body fat

• Anyone can be at risk, depending on their body fat percentage, not their weight

No one likes being sick, and no one likes having to manage diseases like diabetes that stick around for a lifetime. To help you avoid these problems, one of the best ways to determine if your body fat is excessive and/or causing inflammation is to have your body fat percentage determined.

Once you have your body fat percentage, you can compare it against the normal ranges for men and women.  For men, you’ll want to be no higher than about 20% body fat; for women, try to stay under about 28%. These ranges may vary slightly depending on whichever source you consult, but these are good guidelines and agree with the ranges set by the American College of Sports Medicine and American Council on Exercise.

If you reduce your fat mass to a healthy range, you will subsequently reduce inflammation and boost your immune system. Having a killer “beach bod” may not motivate you, but what about a healthy body and fewer sick days?

Everyone should see the value in that.