6 habits that hijack your immune system

It’s pretty clear that, right about now, your immune system is your best friend, and it should be treated with loving care.

It’s the best defense any of us have against respiratory and other illnesses that will make us a sitting duck for a COVID-19 infection, should we come in contact with the virus.

And of course, if you do become exposed to the virus, your immune system is on the front line.

You probably already know that good nutrition, adequate sleep and plenty of exercise all support a healthy immune system, so I’m not going to tell you about those things.

But there are some lesser-known habits you may be engaging in right now that are compromising your immune system’s ability to protect you…

Too much exercise is harmful to your immunity

Daily exercise will keep your heart muscle younger and more flexible. But there’s also evidence that intense exercise causes a temporary decrease in immune system function.

Research has found that the body produces cortisol and adrenaline, better known as our stress hormones, during intense physical exertion. These raise blood pressure and cholesterol levels and suppress the immune system.

So, as with so many things, moderation is the key to your exercise routine.

Related: Yoga for immunity

Researchers at the National Cancer Institute found that 150 minutes of moderate weekly exercise — that’s only about 20 minutes daily — can increase your life expectancy by almost 3.5 years.

And Dr. Dean Mitchell of Touro College of Osteopathic Medicine, says that “too much exercise increases Interleukin-6 (IL-6) and depresses immune system function.”

Overexposure to UV rays, both outdoors and indoors

Sunlight and fresh air are necessary for your health, but overexposure to UV rays can be dangerous. You should always protect yourself by using a good-quality, high-SPF sunscreen. A bad sunburn can increase your risk of skin cancer.

And it can mess with your immune system.

According to the World Health Organization, there is evidence that exposure to high UV levels can alter the activity and distribution of some of your immune system cells.

You can limit your UV exposure indoors, too, by changing your screen settings to eliminate blue light exposure and by taking regular screen breaks during this “virtually connected” time.

Too much salt

The fact that a high salt, highly processed diet is bad for your health on many levels is no secret. But what it does to the immune system is not as well known.

Researchers in Germany discovered that when the kidneys detect excess sodium in the bloodstream and excrete it in the urine, the process also raises the level of steroid hormones called glucocorticoids, which inhibit the ability of neutrophils (a type of white blood cell) to kill bacteria.

Too much alcohol

Dr. John Spangler, a professor of family and community medicine at Wake Forest Baptist Medical Center in North Carolina, explains why even one bout of excessive drinking can reduce the immune system’s response to invading pathogens like viruses and bacteria.

“Alcohol’s major metabolite, acetaldehyde, likely impairs ciliary function in the lungs, making them more prone to bacterial and viral invasion.”

In other words, when alcohol breaks down, it produces a chemical that weakens the lungs and makes them more vulnerable to infection.

Alcohol also impairs the process of attacking and breaking down bacteria and viruses, Dr. Spangler says, and that puts people who abuse alcohol at higher risk for infection.

Too much sugar

Studies have shown that eating too much sugar can impair the performance of white blood cells and reduce your defense against bacterial infections.

Specifically, the function of phagocytes is affected.

Phagocytes are immune cells that capture and break down bacteria and other large invading particles. After consuming just 100g (about 3.5 ounces) of glucose, phagocyte activity may be reduced for up to five hours.

Nicotine

Whether you’re smoking traditional cigarettes or e-cigarettes, you’re still being exposed to nicotine, which can have harmful effects on your immune system.

Nicotine increases cortisol levels, and an excess of this stress hormone can cause overproduction of anti-inflammatory cytokines. (With COVID-19, one of the things that often proves fatal is not the virus itself, but a cytokine storm).

Related: Why smokers’ lungs are extra receptive to coronavirus

Dr. Spangler of Wake Forest Baptist Medical Center tells us that nicotine cuts back on the formation of B cell antibodies, as well as slowing or suppressing the response of the body’s T cells, whose role it is to destroy infected cells.

Taking care of your immune system

It may seem obvious, but a diet loaded with fruits, vegetables and grains is your best bet for supporting your immune system. A Mediterranean-style diet is versatile and especially easy to prepare, now that summer fruits and veggies are widely available.

As part of the Mediterranean style of eating, it’s OK to include a glass of wine with dinner. If you enjoy red wine, all the better. It will help balance your gut bacteria and further support your immune system.

If you’re a smoker, now would be a great time to look at ways to quit. Reach out to a friend who’s also trying. Share the research with them. Maybe they’ll join you. It’s always easier with a partner!

Sources:

1. 7 surprising things that can hurt your immune system — Health24
2. Too much salt weakens the immune system — Universität Bonn
3. Excess dietary salt may weaken immunity against bacteria in the kidneys — Medical News Today
4. 9 Surprising Ways You’re Weakening Your Immune System — EveryDay Health
5. Role of sugars in human neutrophilic phagocytosis — The American Journal of Clinical Nutrition
6. Does sugar weaken the immune system? — Biotics Research Corporation