Fending Off Flu With Food

The best ways to protect yourself from the flu are vaccination, regular hand washing and getting enough sleep. But eating a well-balanced diet with some key nutrients may thwart flu as well. (And it may surprise you that vitamin C is not one of them.)

Vitamin D

Add bolstering immunity to the growing list of this vitamin's perks. In one study, people with low blood levels of vitamin D were somewhat more likely to have had an upper respiratory tract infection than people with higher levels. It appears that this vitamin helps the body produce an antimicrobial substance that defends against infections.

How to Consume Enough: Eat fatty fish like salmon, herring and light tuna canned in oil. Also, drink D-fortified low-fat milk and orange juice. Yet even if you have these items, you may still fall short with the optimal vitamin D amount recommended. So supplement with 1,000 units of this vitamin (preferably the D3 version) -- especially during the remaining winter months when access to sunlight is scarce.

Protein

If you don't eat adequate protein, your body has to break down its own tissue to make some of this necessary nutrient. This can impede immunity. Sufficient protein ensures a decent supply of circulating white blood cells and antibodies, which are essential to a highly functional immune system.

How to Consume Enough: Eat two to three servings a day of low-fat dairy foods, soy foods, nuts or dried beans, plus up to a daily serving (three ounces) of fish, skinless poultry or lean meat. This makes you more likely to meet the Recommended Dietary Allowance (RDA) for protein: 63 grams a day for men and 50 for women.

Unsaturated Fat

Omega-3 fatty acids may enhance immunity by squelching inflammation. They may also boost white blood cells. Other research has found that a higher intake of a specific monounsaturated fat, called oleic acid, decreased pneumonia risk. It, too, acts by controlling the immune system.

How to Consume Enough: Eat fatty fish (such as those mentioned above), omega-3 enhanced eggs, tofu, walnuts and ground flaxseed. Choose canola and olive oils as your main oils. And if you don't eat fish, consider an omega-3 supplement -- one that has a combined 1,000-milligram total of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Zinc

This mineral is crucial for supporting healthy immune cells. Zinc's effective anti-inflammatory and antioxidant properties help fight viruses. In a study of older individuals, those with lower than ideal blood levels of zinc were more likely to get and die from pneumonia.

How to Consume Enough: Eat beans, lean red meat and nuts, such as cashews and peanuts. It is not necessary -- and perhaps not even helpful -- to rely on zinc lozenges. Evidence regarding efficacy has been contradictory and often weak. It may be worthwhile to take a multivitamin supplement -- especially during flu season -- as most brands provide the recommended daily value of 15 milligrams. Avoid single high-dose zinc supplements, as too much of this nutrient can actually interfere with immunity.

What About Herbs?

There's no shortage of herbs linked to combating colds and fighting flu. Among the most popular are echinacea, ginseng, garlic and elderberry. Studies involving these herbs are either not well-designed or have conflicting or unclear results. Fortunately, many of these same herbs don't have a high safety risk.

Certainly, there are no guarantees that you won't come down with the flu this season. However, reducing your risk of flu is within your reach if you adopt a lifestyle that includes getting your flu vaccine, using good personal hygiene, eating healthy foods, being physically active, managing stress levels and not shortchanging yourself on sleep.