Your diet is the first line of defense against catching miserable colds this winter -- there are specific vitamins and nutrients that you can eat to help bolster your immune system. "Think of nutritious foods as part of your cold-season armor," says Jeannie Moloo, PhD, registered dietitian and a spokesperson for the American Dietetic Association. "A healthy diet full of whole grains, fruits, veggies, and low-fat meat will certainly help ward off those nasty colds."

Water is also a key ingredient in your anti-cold diet, says Moloo. "Drinking plenty of fluids, preferably water and decaffeinated drinks, gives your body what it needs to stay healthy," she says. "If you're dehydrated you're more susceptible to catching cold." So, keep bottles of water on hand, and add these items to your shopping list this winter:

Research shows that one cup of yogurt a day may work to keep the gastrointestinal track healthier, which can help ward off colds, says Moloo. Even better, some new studies indicate that regular dairy consumption may help you maintain a healthy weight, or even shed a couple pounds. Make sure the label says your yogurt has live cultures, as the cultures are what have the positive effect on your GI track.

Recommended serving size: Plain low-fat, one cup, 112 calories Low-fat with fruit, one cup, 122 calories

Trade in your sugary breakfast cereal for a bowl of muesli, a whole grain oat-based cereal with dried fruit, nuts, and seeds. Whole grain foods like muesli contain more nutrients than highly processed foods, specifically zinc and selenium, which help keep your immune system strong. If muesli is not your thing, try a whole grain oatmeal instead for similar health benefits.

Recommended Serving Size: Muesli, scant 2/3 cup, 183 calories

It's no surprise that oranges made our Superfoods list because of their high vitamin C content, a common cold-fighter. Just one orange a day provides your recommended daily allowance of vitamin C. In fact, eating a whole orange is preferable to drinking a glass of orange juice, because it doesn't have the added sugars and preservatives that processed juice often contains. An easy and inexpensive fruit to find during the winter, oranges are also rich in flavonoids that may have an antioxidant effect.

Recommended Serving Size: One orange, 60 calories

Go heavy on the garlic this winter in your dinner recipes. This flavor-packed vegetable is also packed with allicin, an antibiotic that has been shown to prevent complications from a cold in some research. According to Moloo, some studies recommend as much as one clove a day. So if you don't already own a garlic mincer, now is the time to get one. Add fresh minced garlic to some plain hummus for a quick snack, or rub it on a steak for a burst of flavor.

Recommended Serving Size: One clove, 3 calories

A good source of protein, zinc, and selenium, lean ground beef can help keep your cells healthy and fight off illness. Flavor your lean ground beef with a little garlic, shape into hamburgers, and serve on whole grain rolls for the ultimate cold-fighting dinner for your family. Add a tomato for some extra vitamin C!

Recommended Serving Size: Lean ground chunk, raw, scant cup, 137 calories

One of the best vegetable sources of vitamin C, green bell peppers are a great item to include in your salads and dinner entrees when it comes to fighting off colds. Flavonoids found in the peppers actually are thought to enhance the antioxidant action of the vitamin C. Green peppers also contain a natural painkiller, capsaicin, that is clinically proven to be effective when rubbed on joints in a cream form. Saute some green peppers and onions and serve as a side with steak, burgers, or chicken. Or slice fresh peppers into strips and dip them into that garlic-flavored hummus for an afternoon snack. Your stuffed-up head will thank you for it.

Recommended Serving Size: Raw, cut into strips, one cup, 15 calories

Originally published on BHG.com, November 2004.