Special to CSMS Magazine
For you to stay healthy and to recover quickly from illness, your immune system must be healthy. What can you do to optimize immune function? Exercise and stress reduction help. But evidence suggests that the most important contributor to immune function is what you eat.
The antioxidant shield
By now, you have probably heard about free radicals. These ubiquitous molecules cause cells to break down, speeding the aging process, promoting heart disease and cancer and weakening the immune system. There’s no way to avoid free radicals. They’re produced within the body as result of normal metabolic processes. But certain antioxidant compounds destroy free radicals.
- Vitamin E. This potent antioxidant forestalls the gradual decline in immune function brought on by aging. It boosts synthesis of antibodies and encourages reproduction of key infection-fighting cells called lymphocytes. People who take vitamin E supplements mount a stronger immune reaction against invading viruses and bacteria. They also enjoy a reduced risk for terminal cancer. Good sources of vitamin E: grains, seeds, and vegetables oils.
- Carotenoids. These antioxidants increase the numbers of lymphocytes and natural-killer cells. Supplements are available, but the best sources are fruits and vegetables, especially carrots, kale, tomatoes and cantaloupes.
- Vitamin C. It energizes the immune system to react more vigorously to cancer cells and microbes. Diets rich in vitamin C have been linked to reduce risk for breast, colorectal and prostate cancer. The optimal intake of vitamin C is 200 milligrams (mg) a day. You can get more than enough through your diet. Good sources of vitamin C: citrus fruits, cantaloupes, and green peppers. Caution: Larger doses can cause stomach troubles, kidney stones and in some people problems iron met
Minerals are needs for synthesis of proteins, which are key components of all cells and enzymes in the body…
- Zinc. The most important mineral for immune functions, zinc boosts the number of lymphocytes and helps natural-killer cells attack cancer cells. The average person needs 15 mg of zinc a day. Higher dosages seem to impair immune function. Good sources of zinc: One serving of fortified cereal (check labels) provides all the zinc you need. Meats (especially cooked oysters) and whole grains. Another note: Zinc supplements generally are not necessary.
- Iron. An iron deficiency increases infection risk by weakening many different types of immune cells. Too much iron also impairs immune function. Women of childbearing age need 15 mg of iron a day and men need about 10 mg of iron. Good sources of Iron: Meats, tofu, and beans. Another note: Iron pills are a good idea only if a doctor has found you to be iron-deficient.
- Selenium. This mineral encourages growth of immune cells and stimulates production of antibodies. Good sources of Selenium: Grains, nuts, seeds, and fish.
Another note: Higher dosages of Selenium can cause neurological and digestive problems.
Excess dietary fat impairs your cells’ ability to recognize viruses and bacteria, crippling your immune response. Even a diet that’s moderately high in fat (41% of calories) halves the cancer-killing ability of immune cells.
Self-defense: Limit your intake of all fats to 25% of your local caloric intake. For most people, this means 44 grams (g) to 55 g of fat a day. Avoid whole milk (8 g fat per eight ounces) margarine (11 g per tablespoon) fatty meat (14 g per in three ounces of lean ground beef) and nuts (18 g per ounce of pecans)
Research is beginning to confirm what traditional healers have long known that certain foods and herbs boost immune function…
- Shiitake mushrooms. Studies in Japan show that these mushrooms boost immune function and inhibit viral multiplication. In Japan, a shiitake derivative called lentinan is used as a cancer fighting drug. Shiitakes are tasty in soups, stews, and vegetables dishes. Eat two to six shiitakes a week.
- Reishi mushrooms. These Chinese mushrooms boost reproduction of lymphocytes and trigger production of chemical “messengers” that coordinate immune system activity. Eat two to four resishis per week.
- Garlic. Garlic is a good source of selenium and of certain compounds with anti-infection and anticancer properties. Season food with garlic at least three times a week.
- Echinacea. This popular herb boosts the ability of immune cells to swallow up cells infected with viruses and stimulates production of compounds that coordinate the immune system’s response against yeast infections. Echinacea extract should be taken for no more than three days in a row—when you have a cold or flu, or feel one coming on. The usual dose is 30 drops of Echinacea tincture, twice a day.
Note: Josette Carnash is a nutritionist who lives and works in Suburban San Diego. She wrote this piece, especially for CSMS Magazine.