5 surprising ways you're weakening your immune system

By Alistair Gardiner
Published May 20, 2021

Key Takeaways

The first step to keeping our immune system in good shape is adopting a generally healthy lifestyle. We know the drill: Eat lots of fruits and vegetables, get regular exercise, maintain a healthy weight, don’t smoke, limit drinking, and wash your hands often to avoid infection.

These practices may seem obvious, but keep in mind there's a plethora of ways you could be weakening your immune system without realizing it. Here’s a look at five factors that might be harming your immune system, according to studies and health experts.

1. Consuming too much fructose

Fructose is the sugar found in fruits, sodas, and many processed foods, and it is widely consumed in this country. According to a new study, consuming too much of this form of sugar may harm your immune system. 

The study, published in Nature Communications in February, looked at the impact of fructose on the function of immune cells. While fructose has long been associated with obesity, type 2 diabetes, and liver diseases, its effect on the immune system hasn’t been explored. 

Through a series of experiments conducted on mice and human cell cultures, researchers found that fructose consumption leads to inflammation of the immune system, which in turn can lead to cell and tissue damage. 

While more research is required before reaching a thorough understanding of this mechanism, researchers noted that high fructose corn syrup can account for as much as 10% of caloric intake for some Americans, which highlights the need for further studies to explore the role that fructose plays in immune system inflammation.

If you want to limit your fructose intake, cutting back on sugary sodas might be a good place to start. But don’t be fooled into thinking diet sodas are the answer. Learn more at These ‘healthier' drinks may do more harm than good on MDLinx. It might be enough to make you reach for a glass of water next time you’re thirsty. 

2. Loneliness

The pandemic necessitated social distancing, but once it’s safe to socialize normally again, your immune system will thank you for getting out and meeting up with some friends and family. 

“The psychological effects of social isolation can affect your immune system,” wrote the authors of an article published by MIT Medical. “The culprits are loneliness and stress...Research shows that our antiviral response is suppressed when we feel lonely.”

Studies cited by MIT Medical indicate that those who perceive themselves as more “socially connected” tend to have increased longevity and may even be less susceptible to the common cold.

This is reiterated in an article published by the American Psychological Association, which states that perceived social isolation is linked with adverse health outcomes, including impaired immunity, at every stage of life. The article cites a study published in the Proceedings of the National Academy of Sciences, which found that feelings of loneliness increased the expression of genes involved in inflammation and decreased the expression of genes involved in antiviral responses in white blood cells—the agents that play a key role in the immune system’s response to infection.

Learn more about the adverse health effects of loneliness and what you can do about it, with New epidemic affects nearly half of American adults on MDLinx.

3. Day-to-day stress

If you’re the kind of person who stresses about getting ill, we have bad news for you: That may be a self-fulfilling prophecy. According to an article published in Stress Challenges and Immunity In Space, decades of research have linked psychological stress to immune system outcomes, including inflammatory processes, wound healing, and responses to infections and other immune system challenges.

The article details how stress disrupts the interplay between the central nervous system, endocrine system, and immune system, which leads to dysregulation of the latter. Stressful situations prompt the release of hormones that interfere with immune function, including the adrenocorticotropic hormone cortisol, growth hormones, prolactin, epinephrine, and norepinephrine. Additionally, chronic stress can deregulate immune responses, and thereby induce inflammation and suppress the function of immuno-protective cells.

Fortunately, there are ways to dial down your own stress. See Here’s how doctors can conquer work-related stress on MDLinx.

4. Not getting enough sleep

Evidence suggests that if you’re not sleeping well, you may be at a greater risk of getting sick. According to the Mayo Clinic, a lack of sleep can also affect how quickly you recover. 

During sleep, the immune system releases cytokines, a type of protein that not only helps you sleep but also helps combat infections or inflammation. When you don’t get enough sleep, the production of these proteins is disrupted, and levels of infection-fighting antibodies and cells also decrease.

Adults should be getting 7-8 hours of sleep a night, while teens should be getting 9-10 hours, and children may need 10 or more hours, noted the Mayo Clinic.

Ready to learn how to get a better night’s sleep? See 7 steps to stop insomnia on MDLinx.

5. Sunburn

While research shows that vitamin D provided by the sun can offer a boost to the immune system, too much sun may have the opposite effect. 

According to an EPA warning, overexposure to the sun’s UV radiation can lead to suppression of the immune system. The WHO has also noted that a growing body of evidence suggests UV radiation can disrupt some of the cells responsible for prompting immune responses, leaving people more susceptible to infections. The WHO cited a study that examined the impact of wearing sunscreen on a group of individuals carrying the herpes simplex virus. Researchers found that when members of the group were exposed to sunlight without sunscreen, a majority of them experienced a resurgence of cold sores; in contrast, when the group used sunscreen, none of them developed a cold sore. 

To learn more about vitamin D’s health benefits, see Studies show vitamin D fights these 3 diseases on MDLinx.

The bottom line

In short, the best immune system-boosting advice is to try to live a healthy lifestyle. But for extra protection, you might want to lay off the soda, stay social, ensure you get enough sleep, and wear sunscreen to help keep your immune system working at its finest.

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