7 Simple Ways to Optimize Your Immune System

Help keep your immune system in peak form with these tips from Michael F. Roizen, MD.

A middle aged man and woman look at a computer tablet and discuss a recipe, while surrounded by fresh fruits and vegetables in a sunny kitchen.

Updated on August 19, 2022.

You may have only a vague concept of DNA and cells. Yet as a “genetic engineer” of sorts, you have the power to help determine, on a daily basis, which of thousands of your genes are turned off or on based on your own choices and behavior. Each healthy act switches on youth-promoting genes and switches off genes that cause you to age.

Science tells us that when you are under the age of six, your genes determine what happens in terms of your health. But by the time you are 55, a greater share of your health is determined by your choices, which dictate which of your genes are on and which are off. So while your genetic component at birth certainly has some influence on your ultimate health and longevity, life outcomes are much more about engineering via your behaviors, choices, and decisions than they are about genes.

How to self-engineer your immune system

We cannot know for certain how quickly new medical advances will happen, what the costs will be, or how accessible these treatments and/or diagnostics will be. (You probably won’t be able to go to a walk-in clinic for a kill-cancer patch in the foreseeable future.) That’s why we advocate for your own preventive behaviors. Because one thing is certain: A higher functioning defense system will be your best protection against cancer and other forms of aggressive disease.

That’s not to say that you can prevent or treat every serious condition by behavior alone—but you will certainly stack the odds in your favor if you do. Here’s what we recommend:

Hunker down in the produce section. The absence of various micronutrients in your diet can decrease your immune function, so diversify your portfolio of leafy greens, cruciferous vegetables, berries, and citrus fruits. Aim to really get a variety. This will help improve the chances that all of your micronutrients—such as vitamins A, B, C, D, as well as minerals like zinc and selenium—are being covered.

Eat (the right) protein. Protein is key, since it’s a building block of antibodies that are integral to your immune function. Salmon’s healthy fats are good for the brain and whole body. You can also get protein from cooked beans and legumes and lean white meats, like chicken or turkey. As much as possible, stay away from red meat and processed meats.

Make the cuts. For improved immune function and to help prevent cancer, it’s best to limit added sugar, added syrups, and simple carbohydrates. But even better, eliminate processed foods and swap in whole foods like fresh vegetables, fruits, whole grains, and lean proteins.

Move, move, move. Get your motor revved. One study that examined older adults found that physical activity was associated with a hearty production of protective T cells. Note here: Don’t overexercise. Overexercising (running, biking, or otherwise training continuously for more than two hours) causes inflammation and depresses your immune system.

Don’t overmedicate. Medication is one of our most important social advances; we have significantly lengthened the human life span with our ability to treat, cure, and prevent disease. That said, overmedicating can be counterproductive, as it has the potential to mess with your immune function (overriding it, in effect).

Though we can’t give guidelines for this because every person’s case is unique, we do recommend that you discuss your medication and supplementation regimen with all of your doctors—and this also goes for any over-the-counter medications and supplements you take regularly.

Get your vaccines. Stay up to date, and get an annual flu shot. The flu increases overall inflammation, and research suggests that getting an annual flu shot for 10 years, from ages 50 to 60, decreases heart attacks and strokes by 50 percent and death in this age group by 25 percent, probably by decreasing the inflammation that accompanies the flu, and the plaque breakage that inflammation causes.

The vaccine for COVID-19 prevention must be added to prevent heart attacks, strokes, memory loss, and kidney disease that may result from COVID-19 inflammation. Taking a multivitamin for several weeks and getting great sleep for several days prior to a flu shot may help boost the flu shot’s success in protecting you from the influenza viruses.

Take time for you. One of the major threats to your immune system is chronic stress; the cascade of hormonal responses it causes weakens your immune function over time. Chronic stress can lead to a buildup of cytokines, which, while fighting infection, can also hurt your own cells in the process. And yet, in some circles, “self-care” is an eight-letter four-letter word.

People pooh-pooh the idea of self-care because, they say either (a) they don’t have time or (b) they’re too tough. (“I don’t need no stinking self-care.”) And we get it; it’s our nature to put others before ourselves. But as the Cleveland Clinic’s great gynecologist, Linda Bradley, MD, says, “You can’t pour from an empty cup!!!”

Think of it this way: If you don’t take time to care for yourself, you won’t be around long enough to be with the people you really want to help and be with anyway.

While there’s no such thing as total stress relief (after all, stress is simply a byproduct of living a fulfilling and challenging life), there are ways to self-engineer the effects that negative and chronic stress can have on your body. These include meditating, practicing deep breathing, maintaining positive social connections, and getting at least 6.5 hours of quality sleep every night.

Excerpted and adapted from the book The Great Age Reboot, by Michael F. Roizen, MD with Peter Linneman, Ph.D. and Albert Ratner. Copyright © 2022 by Michael F. Roizen, MD. Reprinted by permission from National Geographic.

Buy your copy of The Great Age Reboot today.

Article sources open article sources

Christensen K, Holm NV, McGue M, Corder L, Vaupel JW. A Danish population-based twin study on general health in the elderly. J Aging Health. 1999;11(1):49-64.
Bartlett DB, Duggal NA. Moderate physical activity associated with a higher naïve/memory T-cell ratio in healthy old individuals: potential role of IL15. Age Ageing. 2020;49(3):368-373.
Bernat-Adell MD, Collado-Boira EJ, Moles-Julio P, et al. Recovery of Inflammation, Cardiac, and Muscle Damage Biomarkers After Running a Marathon. J Strength Cond Res. 2021;35(3):626-632.
Chiang MH, Wu HH, Shih CJ, Chen YT, Kuo SC, Chen TL. Association between influenza vaccination and reduced risks of major adverse cardiovascular events in elderly patients. Am Heart J. 2017;193:1-7.
Mohseni H, Kiran A, Khorshidi R, Rahimi K. Influenza vaccination and risk of hospitalization in patients with heart failure: a self-controlled case series study. Eur Heart J. 2017;38(5):326-333.
Calder PC, Carr AC, Gombart AF, Eggersdorfer M. Optimal Nutritional Status for a Well-Functioning Immune System Is an Important Factor to Protect against Viral Infections. Nutrients. 2020;12(4):1181. Published 2020 Apr 23.
Spiegel K, Sheridan JF, Van Cauter E. Effect of sleep deprivation on response to immunization. JAMA. 2002;288(12):1471-1472.

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