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10 Sneaky Immune Saboteurs—and How to Fix Them

We've never been more focused on immunity. But despite our best intentions, some common daily habits may be undermining our immunity.

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1. An overzealous supplement routine

Mega-dosing on supplements to fight infections? Ultra-high doses of certain vitamins and minerals can impair your immune health. Selenium and zinc are known for their critical roles in immunity, but lavish doses of either hamper the body’s immune response and diminish resistance. Excess vitamin A can shut down the body’s trained immunity, increasing susceptibility to otherwise-benign pathogens. And taking handfuls of “immune-boosting” herbs and supplements can exacerbate existing autoimmune disease or trigger autoimmune conditions in genetically predisposed people.

For balanced support, eat a nutrient-dense diet and use supplements in recommended—not heroic—doses. Some to consider for immune health include vitamins C and D, zinc, elderberry, medicinal mushrooms, Korean ginseng, and Xlear Nasal Spray. (Xlear is technically not a supplement, but it has been shown to help block viruses from adhering in the nose and to keep mucous membranes moist.)

2. Isolation

After 18 months of social distancing, isolating may have become a way of life. If so, it’s time to break that habit. Feeling lonely suppresses the body’s virus-fighting mechanisms, and ongoing isolation is linked with sadness, depression, and diminished immunity. You don’t have to become an overnight social butterfly. Small doses of human contact can boost resistance, and even hugging can lessen stress and improve immunity. And if you’re in a relationship, regular intimacy increases levels of pathogen-fighting compounds—weekly sex seems to have the greatest effect.

3. The wrong fat-to-protein ratio

Keto and other low-carb plans offer plenty of benefits. But too much dietary fat—namely overly processed fats—may affect cellular immune health and dampen resistance. Some research also shows that saturated fats from conventionally raised meat, butter, and cheese (not organic, grass-fed varieties) can disrupt gut bacteria, critical for a healthy immune response and resistance to pathogens. Heavy consumption of animal protein, especially conventionally raised red meat, can also disrupt the microbiome. The same goes for sugar alcohols commonly used in low-carb diets. If you’re following a Keto diet, focus on clean fats  and protein sources, and emphasize fiber to support beneficial gut bacteria. Also consider cutting back on sugar alcohols or using stevia or monk fruit instead.

4. Way too much time spent indoors

If you’re still working from home—and getting about as much sunshine as the average vampire—it’s time to head outside to protect your immune health. Exposure to the sun’s rays triggers vitamin D production, crucial for resistance to infection. In addition to boosting D, sunlight activates T cells that play a central role in human immunity. Plus, plants, trees ,and other green things produce compounds that appear to increase the number and activity of white blood cells. Just don’t get too much sun—exposure to UV light (even enough for a mild sunburn) suppresses immune response. In the summer, 5–15 minutes of sunlight each day is enough. In the fall and winter, you may need more. Or cover your bases with a supplement—research suggests that 500 IU per day of oral vitamin D3 is as effective as sunlight.

5. An 80-hour work week

Movers, shakers, and captains of industry might want to dial it down a notch. Chronic stress suppresses the immune system, decreasing protective cells and prompting inflammation. Some research shows that demanding, stressful careers have a measurable, detrimental impact on immune parameters, reducing natural killer cell activity and increasing markers of inflammation. The effect is even more pronounced if you’re dissatisfied with your job. Any sources of stress (tense relationships, financial woes, or a high-anxiety lifestyle) can have the same consequences. And ongoing anxiety disrupts gut bacteria, reducing overall diversity and harming immune health. If you need to tone it down, stress-busting supplements like L-theanine, valerian, and lemon balm can help.

6. Fierce workouts

Exercise is generally good for immunity. Regular physical activity activates the immune system’s pathogen-fighting potential, and studies show that a couch-potato lifestyle significantly diminishes the body’s ability to ward off infection. But strenuous or excessive workouts can backfire. Overtraining without alternating rest and recovery can impair immune function, and research suggests that prolonged, intensive bouts of training can increase the risk of infections, especially of the upper respiratory tract. So exercise, but be balanced. Shoot for 30–60 minutes a day of moderate-intensity activities, and give yourself time to rest between rigorous workouts.

7. Excess alcohol

The occasional happy hour cocktail probably won’t hurt—but regular, heavy drinking promotes inflammation and damages immune health. Alcohol is broken down into acetaldehyde, a toxic compound that interferes with immune-cell activity and with the lungs’ ability to sweep out bacteria and viruses. In fact, one night of excessive drinking can significantly impact immunity. Alcohol also disrupts gut bacteria, further lowering resistance. It’s even worse if your nightly party routine includes smoking or vaping. Nicotine weakens the body’s pathogen- fighting potential, and chemicals in e-cigarettes impair immune responses to bacteria and viruses and can damage lungs, making them more vulnerable to infection (smoking pot also harms the respiratory system and impacts immunity). Put your party animal back in its cage, drink alcohol in moderation, and if you smoke or vape, stop now.

8. Being too clean

Good hygiene is vital for preventing the spread of colds and flu—but obsessively disinfecting every doorknob, counter, and light switch can backfire. Some research suggests that an over-sterile environment confuses the immune system and increases the risk of allergies and autoimmune conditions. That’s especially important if you have kids, who rely on exposure to the occasional germ to develop robust immunity. And scrubbing your whole body with antibacterial soaps and washes disrupts beneficial skin bacteria responsible for fending off harmful organisms. Just keep your home normally clean, wash your hands frequently with regular soap, and minimize contact with anyone who’s sick. And if there’s ever a time to unleash your inner OCD, it’s with your cell phone. Some studies suggest that the average mobile device is 10 times more germy than a toilet seat.

9. Ice cream (and cookies, and peanut butter cups)

That quarantine-inspired sugar addiction may be harming your immune health. Sweet treats boost the body’s release of pro-inflammatory compounds and impair immunity, and some research shows that sugar significantly decreases the capacity of infection-fighting cells for at least five hours. Honey, agave nectar, and other natural alternatives have the same effects. So curb your sweet tooth. Make cookies and cakes an occasional treat, not an everyday event, and swap sugar for stevia and monk fruit. Some studies suggest that stevia enhances the body’s immune response, and compounds in monk fruit promote immune cell proliferation.

10. Late-night Netflix binges

If you’re staying up past midnight to watch just one more episode of that gripping series, you may be lowering your resistance. Exposure to blue light from televisions, tablets, and other devices seriously disturbs restful sleep—important, since your body releases pathogen-fighting cells during slumber, and research links lack of sleep with increased susceptibility to infection. In one study, people who got less than seven hours of shut-eye were nearly three times more likely to catch a cold, and even two nights of sleep deprivation disrupts gut bacteria involved in immune function. Turn off the TV, make a cup of chamomile tea, and unwind before bed. And if you struggle with sleep, try melatonin. Besides supporting slumber, it enhances resistance to viral infections.