White blood cells, or leukocytes, defend the body against infections, diseases and foreign materials as part of the immune system. As with all body systems, effective immune system function depends largely on proper nutrition. Maintaining a healthy diet with immune-boosting foods can help your white blood cells perform at their best.
Improving Your Immunity
The Harvard University School of Medicine asserts that no current scientific evidence directly links lifestyle to enhanced immunity. However, the preliminary results of several research studies show the beneficial effects of lifestyle factors on immunity, including supplements, exercise and diet. Health care experts emphasize that an overall healthy lifestyle free of smoking, moderate in alcohol and consistent in good sleep, a balanced diet and regular exercise is the best defense against illness.
Fruits and Vegetables
Fruits and vegetables contain essential fiber, lower blood pressure, reduce the risk of heart disease and improve digestive function. They also provide several nutrients important for immunity. According to Dr. William Sears, vitamin C increases production of white blood cells and antibodies; carotenoids, including beta-carotene, support specialized white blood cells called natural killer cells and helper T-cells; and bioflavonoids aid the immune system by protecting the body from environmental pollutants.
Meat, Fish and Shellfish
Certain cuts of meat, fatty fish and shellfish provide zinc, omega-3 fatty acids and selenium. Zinc increases the growth of white blood cells and might improve their function. Selenium, another mineral, increases natural killer cells. Omega-3 fatty acids promote the activity of phagocytes, a type of white blood cell responsible for digesting bacteria and other immune system waste. Sources of zinc, selenium and omega-3 fatty acids include oysters, crab, dark turkey meat, tuna, mackerel, red snapper, salmon, lobster and lamb.
Nuts, Seeds and Vegetable Oils
Almonds, peanuts, hazelnuts, sunflower seeds and oils made from safflower, corn and soybeans contain vitamin E, an important antioxidant. Vitamin E stimulates the production of natural killer cells and B-cells, another type of white blood cell that produces antibodies. The Harvard University School of Medicine notes research that shows vitamin E significantly improving the antibody response to hepatitis B and tetanus after infection.
Leukopenia
A low white blood cell count, medically known as leukopenia, can indicate a serious illness and make you vulnerable to infection. Causes for leukopenia include viral infections, cancer and autoimmune diseases that damage bone marrow, which produces white blood cells, or an infection that consumes white blood cells faster than the bone marrow can replace them. A healthy diet alone cannot improve chronic leukopenia; you must see your physician for proper management.
References
- "Human Physiology: An Integrated Approach"; Dee Unglaub Silverthorn; 2006
- Harvard University Medical School Publications: How to Boost Your Immune System
- Ask Dr. Sears: 8 Foods that Boost Immunity
- Harvard University School of Public Health: Vegetables and Fruits
- MedlinePlus; "Vitamin E"; June 2011
- MayoClinic.com; "Low White Blood Cell Count"; September 2010
