8 Flu-Fighting Foods

Apples

Ever hear of eating an apple a day to keep the doctor away? Apples are one of the best sources of the antioxidant quercetin. (Antioxidant-rich foods strengthen your ability to fight infection and disease.) The fruit may improve immunity and keep you healthy even when you're feeling physically worn down. A group of cyclists took either quercetin supplements or a placebo (a harmless pill) during an intense workout period, as part of a study conducted by researchers at Appalachian State University. Those on the quercetin had a significantly lower chance of developing an upper respiratory tract infection (in the nose, sinuses and throat—such as in the common cold) in the weeks that followed than subjects who took the dummy pill. There's a lot we don't know about supplements, though (such as how much of the nutrient they actually contain), so stick with foods rich in quercetin like apples, citrus fruits, onions, parsley and even red wine.

Rachel Meltzer Warren is a New York City–based nutrition writer, educator and counselor.

Reviewed by Elaine Brown, MD on October 27, 2013