5 Behaviors That Are Negatively Affecting Your Immune System

Don't blame the weather—your habits may be to blame for that cold.

It’s that time of year: You wake up more days than not with some orifice clogged with mucus and subdue an irritating scratch in your throat by popping cough drops all day.

You chalk it up to the unavoidable result of spending half of your time in freezing temperatures and the other half in the dry air of your over-heated office. You chug orange juice, green tea, and chicken noodle soup in an attempt to maintain the bare minimum of health required to function until the warm temperatures of spring bring you some relief.

But the weather shouldn’t be shouldering all the blame for your struggling immune system. Chances are, some of your lifestyle choices during the winter season may also be making it harder for your body to fend off germs and fight infection. Give your overtaxed immune system a break by correcting these common winter habits.

Not Getting Enough Sleep

Your ambitious gym schedule still feeding off the New Year’s momentum, multiple freelance projects and a long Netflix queue have all been stealing precious hours from your sleep bank. But “it’s during sleep that our body and our cells regenerate,” said Dr. Kathy Gruver, PhD, a health and wellness expert and author of The Alternative Medicine Cabinet. “Running ourselves ragged is very similar to that fight or flight response. Our immune system is basically going to be overwhelmed and not function as efficiently.”

The National Sleep Foundation confirmed that sleep helps sustain the functioning of the immune system, and that chronic sleep loss is a risk factor for immune system impairment. A study published in the journal Sleep found that severe sleep loss has the same effect on the immune system as stress: jolting white blood cells into action. And that inflammatory response weighs on your health and triggers symptoms associated with health conditions like allergies, to more serious diseases like heart disease and diabetes.

A more recent study published in the same journal found that people who don’t sleep enough are at higher risk for developing colds. “Sleep goes beyond all the other factors that were measured,” said Aric Prather, an assistant professor of psychiatry at the University of California, San Francisco, and lead author of the study, in a press statement. “It didn’t matter how old people were, their stress levels, their race, education or income. It didn’t matter if they were a smoker. With all those things taken into account, statistically sleep still carried the day and was an overwhelmingly strong predictor for susceptibility to the cold virus.”

Living in a Constant State of Stress

Some level of stress is normal—and unavoidable. But chronic stress can be taxing on our health. “When we’re stressed, and in that fight or flight [mode], our immune system is depleted,” said Gruver. “At first we see a boost in the immune system response. However, we don’t have short-lived dynamic stress that then fades so we can rest. We have ongoing, low-grade (sometimes high-grade) stress that seems unending. The immune system cannot handle that barrage of stress and chemicals so it doesn’t work as well.”

According to the American Psychological Association, lab studies revealed that for stress of any significant duration—from a few days to a few months or years, as happens in real life—all aspects of immunity went downhill. They concluded that long-term or chronic stress can ravage the immune system.

“Remember that stress isn’t really the problem, but our reaction,” said Gruver. “Doing anything we can to help ourselves respond better to stress will benefit our immune system. There are many things we can do to combat stress; My favorite is mini meditation. Concentrate on the breath and if other thoughts intrude, which they often do, dismiss them without judgment, return to the breath and think, ‘I am…at peace.’”

She also encourages the use of visualization techniques to combat stress and boost immunity. “Studies show that we can activate the white blood cells by visualizing them working more efficiently (whether it’s Pacman eating the infection or an army mobilizing),” said Gruver. “And worrying about getting sick is not going to help you stay any healthier. In fact, creating that stress will again deplete your immune system. Rather than thinking negative thoughts, use positive affirmations like ‘I am healthy and well, my immune system is strong and resilient.'”

Eating Like Crap

It’s a no brainer that our bodies need proper nutrition to function optimally. And all of those comfort-food orders you’re racking up on Seamless aren’t doing much for your health. “If we are deficient in vitamins and minerals our immune system will not be able to fight off infections and disease as efficiently as it could,” said Gruver. “Getting enough water, eating real, whole foods and getting fresh fruits and vegetables is going to benefit us overall. And avoiding toxins and chemicals like artificial sweeteners and high fructose corn syrup is going to take less of a toll on our body.”

Not only does high sugar intake lead to weight gain (which negatively impacts our health), but studies show that it also promotes inflammation in the body. And an often cited study published in The American Journal of Clinical Nutrition found that after ingesting sugar, participants showed a decreased neutrophilic response (the process in which offensive microbes are destroyed).

Making a conscious effort to limit not just sugar, but also salt and unhealthy fats is key to reaping immune-boosting benefits. A recent study published in Nutrition Journal, found that the typical American diet (high in processed foods that have a significant amount of all three culprits) can lead to increased inflammation and a significant decline in overall immune function.

 Making Frequent Appearances at Happy Hour

The searing cold drives you right into the back of a low-lit pub for a malty brew. But indulging in alcohol too frequently can backfire when it comes to your health: According to the National Institute on Alcohol and Alcoholism, “alcohol suppresses both the innate and the adaptive immune systems. Chronic alcohol use reduces the ability of white blood cells to effectively engulf and swallow harmful bacteria.” Drinking in excess also disrupts the production of cytokines—chemical messengers that in abundance can damage your tissues and when depleted leave you open to infection. The behavior also suppresses the development of T-cells and can impair the ability of NK cells to attack tumor cells. This makes you more vulnerable to bacteria and viruses, and less capable of destroying cancerous cells.

And it’s not just chronic use: binge drinking on a single occasion can also compromise your immune system. Being intoxicated causes inflammation that hinders your body’s ability to produce the cytokines that ward off infections. Without these inflammatory responses, you reduce your body’s ability to fight off bacteria. Studies showed that slower inflammatory cytokine production can reduce your ability to fight off infections for up to 24 hours after getting drunk.

Maybe it’s time to pencil in a few coffee dates instead.

Exercising Too Much

Staying physically fit and maintaining a healthy weight is a key component of keeping your immune system functioning optimally, but logging too many hours of intense exercise in the gym can have the opposite affect, leading to a temporary decrease in immune system function.

“Too much exercise can lead to a dramatically increased risk of upper respiratory infections (URIs),” wrote Mark A. Jenkins, MD. “The stress of strenuous exercise transiently suppresses immune function. This interruption of otherwise vigorous surveillance can provide an ‘open window’ for a variety of infectious diseases—notably viral illnesses—to take hold.”

And if you’re training for a longer, endurance race or event, take note: “This is especially true following single bouts of excessive exercise. For example, it has been observed that two-thirds of participants developed URIs shortly after completing an ultramarathon. Similarly, cumulative overtraining weakens the athlete’s immune system, leading to frequent illness and injury,” wrote Jenkins.

Research showed that more than 90 minutes of high-intensity endurance exercise led to the release of certain hormones that temporarily suppressed an athletes immune function, making them more susceptible to illness for up to 72 hours after the workout. Worth noting if you’re training for a marathon and squeezing in a longer run this weekend.

And if you’re already feeling under the weather, you may want to take your workout intensity down a few notches. Your immune system is already strained from fighting off the infection, and intense exercise will add additional stress that may prolong your illness (which your cubicle neighbor won’t appreciate).