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Diet for a Strong Immune System

by Betty Holt

About Betty Holt

Betty Holt began writing professionally in 1966 as co-editor of a summer mimeographed newspaper, "The Galax News." She has written for "Grit," "Mountain Living," "Atlanta Weekly" and others. Holt received a Bachelor of Arts in psychology and Master of Education from the University of North Carolina-Chapel Hill. Her articles specialize in health, fitness, nutrition and mental health.


A healthy immune system is key to fighting off would-be invaders in the form of bacteria, viruses and even cancer. A lifestyle that includes nourishing food, exercise and adequate rest helps maintain a functioning immune system. The foods you eat as well as the ones you avoid play an important role in the health of this system. Certain vitamins can also enhance immune function.

The Immune System

According to "Prescription for Natural Healing," the immune system is a series of complex interactions involving many different organs, structures and substances. It includes white blood cells, the lymphatic vessels and organs, bone marrow, specialized cells in various body tissues and specialized substances called serum factors in the blood. In short, the immune system's job is to categorize those things that are "self," or naturally occurring in the body, and "nonself" which are foreign to the body, and to either neutralize or destroy those that are "nonself." In the case of autoimmune reactions, the body actually turns on itself and begins to destroy its own tissue inappropriately.

What To Eat

The Cleveland Clinic recommends a diet high in antioxidants. Antioxidants scavenge free radicals created from converting food into energy as well as pollution, cigarette smoke and other environmental factors. Foods containing antioxidants include berries, spinach, whole grains, tomatoes, carrots, soy, tea and green leafy vegetables, such as broccoli. Many types of cancers have been connected to diets lacking in antioxidants. Fresh fruits and lightly cooked vegetables and whole grains, which add fiber to the diet, are good sources. Drinking plenty of water to flush out toxins is also helpful.

What Not to Eat

Red meat should be eliminated or severely limited, according to the Cleveland Clinic. Fried meats can be replaced with fish such as salmon, which contains omega-3 fatty acids, a natural anti-inflammatory. Cooking oils other than olive and canola should not be used due to their negative effect on the immune system. The Cleveland Clinic recommends a diet in which no more than 30 percent of daily calories come from fat, and only 7 percent should be saturated, with less than 200 mg per day of cholesterol.


According to "Disease Prevention and Treatment," vitamin A supports immunity by helping maintain the integrity of the body's mucosal surfaces. Beta-carotene, a form of vitamin A, has been shown to boost natural killer cell activity in elderly men. Vitamin E also helps NK cell activity and cell-mediated immunity. The antioxidant vitamin C is especially important to healthy lungs and for "cleaning up" free radicals left behind after killing activity. Vitamin B6 deficiencies have been associated with noticeable immune depression. The minerals zinc, copper, manganese and selenium function as cofactors of antioxidant enzymes and protect against free radicals produced during oxidative stress. Probiotics like lactobacillus acidophilus help create a positive environment in the GI tract for enhanced immunity. Because of its immunostimulatory potential, coenzyme Q10 has been used as an adjuvant therapy in patients with various types of cancer.

Other Factors

Prolonged stress can suppress the immune system, so it is best, as much as possible, to avoid stress and get sufficient sleep. Regular moderate exercise increases T lymphocyte production and has a positive effect on immune response, according to "Prescription for Natural Healing." Overeating, smoking and consuming alcoholic beverages can be detrimental to immune response.

References (2)

Resources (1)

  • "Prescription for Natural Healing;" Phyllis A. Balch, CNC, and James F. Balch, MD; 2000

Photo Credits:

  • John Block/Stockbyte/Getty Images

This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.