The best thing you can do to boost your immune system through diet is to eat plenty of fruits and vegetables.
Will that ward off all illness? Not by a long shot. Although there is some science behind the guidance, it’s important to remember that the immune system is a complicated thing, and there’s still a lot that researchers don’t understand about exactly what affects its performance. Still, science does provide some evidence that a healthful diet can help.
For example, a British study published in the American Journal of Clinical Nutrition in December 2012 followed 83 volunteers, ages 65 to 85, who normally ate only two servings of fruits and vegetables a day. Half the participants were told to increase their consumption of produce to at least five servings a day. It didn’t matter what kinds of fruits and vegetables they ate — they just needed to eat more, and they were encouraged to eat a wide variety.
For this study, a serving of fruit was defined as 80 grams, or just about three ounces, or three-quarters of a cup of fruit juice. A serving of vegetables was defined as three heaping tablespoons.
After 12 weeks, both groups were given vaccines for pneumonia and for tetanus. No differences between the groups were seen from the tetanus shot. However, participants who ate more produce and who never before had received the pneumonia vaccine — Pneumovax II, commonly used in the United Kingdom — developed significantly more antibodies to fight against pneumonia than the others in the study.
In addition, those who ate more produce reported less illness: 20 percent of the five-servings-a-day group reported recent infections or illnesses, compared with 33 percent in the two-portions-a-day group.
While this study focused on older people, boosting intake of fruits and vegetables isn’t bad advice for anyone.
To learn more, the Harvard Medical School provides detailed information through its Flu Resource Center. It offers guidance on:
- Healthy-living strategies that help all parts of your body, including the immune system, function better.
- How to weigh immunity-boosting claims of supplements and other products.
- The interactions of age, diet, stress and exercise on the immune system.
To read the article, go to www.health.harvard.edu and search for “How to Boost Your Immune System.”
Chow Line is a service of Ohio State University’s College of Food, Agricultural, and Environmental Sciences and its outreach and research arms, Ohio State University Extension and the Ohio Agricultural Research and Development Center. Send questions to Chow Line, c/o Martha Filipic, 2021 Coffey Road, Columbus, OH, 43210-1043, or firstname.lastname@example.org.
Editor: This column was reviewed by Dan Remley, field specialist in Food, Nutrition and Wellness for Ohio State University Extension, the outreach arm of Ohio State’s College of Food, Agricultural, and Environmental Sciences.