November 26, 2004

Fight Flu With Good Food Choices ; Boost Immune System With Nutrient Dense and Color-Coded Meals

Stick to the food pyramid.

Eat a rainbow range of foods.

Love thy garlic.

Food scientists, holistic healers and practitioners of folk medicine might differ in their approach to sound nutrition. When it comes to staying healthy in flu season, though, they share a basic belief: Flu, a viral infection, cannot be prevented, but it might be discouraged if you eat foods that enhance the immune system. The same holds true for that other viral scourge, the common cold.

Even if you don't receive a flu shot this season, a healthful diet can only improve your chances of avoiding the nasty bug that causes discomfort at the very least and, in the most extreme cases, death. The United States records 36,000 deaths from flu annually.

"I'm not aware of a strong relationship between a person's diet and the ability to ward off viruses such as the flu, other than a general overall healthy diet to help boost your immune system," says Mark Kantor, associate professor in the nutrition and food science department of the University of Maryland.

If you want to actively work at skipping the flu, start with Kantor's common-sense suggestion: Eat "lots of fruits and vegetables and whole grains, and go easy on the fats and sweets." Then, pay extra attention to the role certain foods and nutrients play in strengthening the body's defense system.

A recent study of elderly individuals found, for example, that vitamins E, B-6 and B-12 "might help boost the body's ammunition against cold and flu," according to a press release from the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University.

"Healthy, nutrient-dense foods are the key to boosting the immune system at every level," says Cindy Heroux, a registered dietitian in Orlando, Fla., and author of "The Manual That Should Have Come With Your Body" (Speaking of Wellness, 2003, $14.95).

Adequate protein (to form antibodies), vitamins B-6 and B-12, as well as vitamins A, C, E, folate (added to fortified cereals), iron, zinc and pantothenic acid found in mushrooms, peanuts and eggs are "the basic nutrients that support your immune system," Heroux says.

For Elena Michaels, a naturopath in Santa Clarita, Calif., a flu- busting meal is as simple as preparing "homemade vegetable soup in a big kettle, with chicken or vegetable broth." Add celery, sweet potatoes, onions and garlic "and it can last all week," Michaels says. "It's very preventive and supports the immune system."

Steering clear of influenza is not about "just taking a multivitamin," says Gretchen Heilman, a Charles Village, Md., holistic health counselor. "A whole array of vitamins can be found in foods of all different colors," she says.

"To keep it simple, I tell people to really eat the whole rainbow." With color-coded eating, you're sure to consume a healthful range of cancer-fighting antioxidants and flavonoids (chemical compounds found in certain fruits, vegetables, teas, wines, nuts, seeds and roots that are antioxidants, she says).

Vitamin A is "very important to the immune system," says Mary Ellen Camire, a food scientist at the University of Maine. Choose squash, spinach, sweet potatoes, vegetables in the dark-orange and dark-green range, she says, adding that they're widely available this time of year.

Nancy Childs, a professor of food marketing at Saint Joseph's University in Philadelphia, is big on orange juice for its high vitamin C content, while Heilman cautions against juice with too much sugar, which, she says, "depresses your immune system."

Heroux discourages consuming large quantities of sugar at the expense of other nutrients people might need.

Flu phobics also may try to front-load their diet with servings of "functional foods," which have been found to lower the risk of certain diseases beyond fulfilling basic nutritional needs.

Garlic, an herb used medicinally since antiquity, "has been shown to have antibiotic and antiviral properties," Heroux says. "You need to eat about two raw cloves a day to get maximum benefit." Although garlic is most effective in its raw state, "you can take it in supplement form, freeze-dried in capsules," Heroux says. By cooking garlic, "you deactivate some of the enzymes," she says.

Kantor, a member of the Institute of Food Technologists in Chicago, also says, "How you cook a food can affect what kinds of biochemicals it has," making it difficult to gauge the potency of cooked garlic.

Yogurt with active or live cultures is another functional food that experts are praising for its ability to promote gastrointestinal health. Friendly bacteria, known as probiotics, can "help to protect the body's defensive barriers by discouraging the growth of infectious bacteria," Heroux says.

Yakult, popular in Asia and Europe, as well as DanActive, available in the United States, are yogurt drinks power-packed with beneficial bacteria. But any yogurt that contains live or active culture also is effective.

"I'm very big on the fermented products," Camire says. "Having those bacteria in our bodies does stimulate our immune system. It helps us to ward off food poisoning and seems to help out the immune system overall."

Other foods with beneficial immune properties that might surpass basic nutritional elements include shellfish, which contain selenium, and salmon, which is rich in omega-3 fatty acids, critical for activating disease-fighting T-cells. Black and green teas are also thought to bolster T-cell production.

Shiitake mushrooms have been used in Japan and China for centuries as an immune booster. More recent studies support their effectiveness in combating colds, flu and other maladies. Reishi mushrooms, ginger, onions and blueberries also are thought to have immune-enhancing properties.

Above all, says Heroux, stay hydrated. Fluids are "really important just to keep the body healthy." Water and other liquids not only "help flush everything through the system," but also prevent nasal passages from drying out, Heroux says, adding that dried-out passages make one more susceptible to invasion by cold or flu viruses.

Water works best, the nutritionist says, followed by herbal teas, regular tea, coffee, fruit juices and other drinks diluted with water and milk.

If the flu still knocks you out, chicken soup remains the ultimate comfort food, even if its legendary curative powers have not been definitively proved. Its steamy broth relieves a congested nose and sinuses, as does a dose of cayenne or chile peppers. And if you make a soup chockablock with carrots, garlic and onions, you're also shoring up your immune system for the next flu season.


Makes 4 servings.

Ginger-Garlic Dressing and Marinade:

1/2 cup oil, preferably soybean or olive

1/2 cup light soy sauce

1/4 cup orange juice or honey

4 tablespoons white or rice vinegar

1/4 cup fresh ginger root, peeled and minced

3 to 4 cloves fresh garlic, minced or pressed

1/4 teaspoon red pepper flakes (optional)


1 pound fresh shrimp

8 cups assorted greens, the darker the color, the better

2 oranges or tangerines, sectioned (or 1 can mandarin orange slices)

2 tomatoes, quartered

1 small red onion, thinly sliced

1 cup sliced or chopped walnuts

Dressing: Make the dressing/marinade by blending ingredients in food processor. Chill 1 cup of the mixture and use the remaining 1/ 2 cup as marinade for the shrimp.

Salad: Peel and devein shrimp and combine with marinade in small covered bowl or airtight bag. Marinate for 1 to 3 hours in refrigerator, then grill.

Wash and dry greens. Top with fruit, vegetables, nuts and shrimp. Serve with chilled dressing.

Nutrients per serving: 556 calories, 29 grams protein, 23 grams carbohydrate, 41 grams fat (66 percent total calories), 168 milligrams cholesterol, 7 grams fiber, 1,734 milligrams sodium.

- Cindy Heroux, "The Manual That Should Have Come With Your Body"