‘Tis the season to feel lousy. The cold season, which began last Fall, peaks this month — flu too. Most Americans average two to six colds a year, a frequency which helps drive the $132 million market for echinacea, an herbal supplement which promises to reduce the duration and severity of colds. But is that money well spent? Probably not, according to a recent study — one of the larger and better designed investigations to date.

Researchers from the University of Wisconsin administered either echinacea, placebos, or nothing at all to a group of 719 patients with colds. The echinacea group got a 10-gram dose on the first day of their colds, and 5 grams daily for four days thereafter. The result: Scores for severity and duration of colds were statistically the same across all groups. So if echinacea has little measurable benefit, what can we do to help support the body’s immune function?

Eat a wide variety of fruit and vegetables, especially top sources of nutrients such as vitamin A (sweet potatoes, carrots, kale), vitamin C (pineapple, broccoli, kiwis), vitamin E (sunflower seeds, almonds), selenium (Brazil nuts, oysters) and zinc (crab, clams). Stay active and watch Dr. Nieman speak on the exercise and immunity research being done at the North Carolina Research Campus). An active lifestyle and healthy diet can also help you avoid excess weight gain, which has been linked to higher rates of hospital infection and viral susceptibility.

Bonus: Don’t sniffle, be happy! A study at Carnegie Mellon University found that subjects who scored highest on the happiness scale were far less likely to develop a cold.

 Published February 1, 2011