Staying Healthy This Winter

It's wintertime, and germs are everywhere, from the staircase at work to the treadmill at the gym. Some of the best ways to combat these germs—frequent hand-washing, not touching your face, avoiding people who are ill—are well documented. But according to many experts, there are additional preventative measures you can take to avoid catching a cold or flu.

A diet that's loaded with fruits, vegetables, and whole grains is one of your best defenses against illness, according to Patricia Kendall, Ph.D., R.D., a professor of food nutrition at Colorado State University in Fort Collins, Colorado. "People who eat plenty of fruits and vegetables tend to have fewer problems with colds," she says. Unfortunately, the average American consumes just two to three servings of fruits and vegetables daily. In order to actually get the immune-boosting benefits of these foods, one must eat five or more servings a day, explains Kendall. An example of a serving would be one cup of leafy vegetables, one medium-size piece of fruit (such as an apple, banana, or orange), or half a cup of chopped fruits and vegetables.

Many people also swear by high doses of certain supplements, such as zinc, echinacea, and vitamin C, to help ward off illness, but is there any merit to these claims? It depends who you ask. "Researchers disagree on whether your immune system gets an extra boost if you take extra vitamins above the levels recommended for general health," says Kevin Fritsche, Ph.D., an immunity researcher and associate professor at the University of Missouri-Columbia.

Experts who do believe supplements can lessen the duration or severity of illnesses emphasize that zinc and echinacea seem to be most effective when taken at the first sign of illness, although echinacea, in particular, should only be used for short periods of time. Vitamin C has been shown to dry up nasal passages, which can bring some relief to cold sufferers. In addition, taking vitamin C regularly may reduce the number and length of your colds. As you would with medications, remember to talk to your doctor before you start taking any new supplements.

In addition to diet, exercise has been shown to promote immune health. The reason? High levels of fatlike substances in the blood called lipids reduce your resistance to disease, but exercise may reverse this by lowering blood lipid levels. Exercise also helps counteract the effects of stress, another known immune suppressor. "It doesn't take that much exercise to enjoy the benefits," says Fritsche. "You don't have to be a marathoner." At least 30 minutes of vigorous exercise three or more days a week should do the trick, he notes.