Here’s an easy way to boost your immune system when you begin to feel a cold coming on this winter—lay off the sugar. When you ingest sugar (and yes, that includes sweet beverages, such as fruit juices), your immune system weakens within 30 minutes, and stays that way for more than five hours, says Michael T. Murray, ND, a well-known naturopathic doctor and coauthor of The Encyclopedia of Natural Medicine (Atria). To stay healthy this winter, he recommends that you have no more than 15 to 20 grams (g) of sugar in any three-hour period. Example: A four-ounce glass of juice has about 12 g of sugar.

In Ayurvedic medicine, the herb ashwagandha is used to treat conditions such as fatigue and memory loss. But it also aids your body when it is besieged by stress. Ashwagandha is an adaptogen that helps to bring the body’s physiological processes into balance and enhances the body’s ability to cope with stress. It contains chemicals that help to calm the brain, reduce swelling (inflammation), lower blood pressure and boost the immune system. It is available online and at health-food stores.