Exercise can reduce risk of infection

Q. Does physical activity protect against catching a cold or wear down your resistance?A. Regular moderate physical activity reduces the risk of respiratory infections, according to the American College of Sports Medicine.The common cold is an upper respiratory infection caused by a virus. Whether you get sick with a cold after you've been exposed to the virus depends on many influences on your immune system, such as how well you're eating and whether you've been getting enough sleep, as well as age, stress and tobacco use. Physical activity seems to be among those important influences, too.A few randomized controlled studies have shown that people walking 35-45 minutes five days a week reported about half as many days with cold symptoms as inactive people in the studies. Part of this protection may come from promotion of healthy IgA levels, antibodies particularly linked with fighting colds and other respiratory infections.In several studies of seniors aged 65 and above, those assigned to an aerobic exercise group showed higher IgA levels than did a control group. However, while regular moderate exercise seems to strengthen immune function, intense heavy exercise (as in marathon runners and elite athletes) may decrease immune function and leave people more vulnerable when exposed to cold viruses.Q. Is kosher food more healthful than other food?A. Kosher food is one of the fastest growing categories of food in the U.S., and people who are not Jewish purchase most of it.A national survey found that the majority of people who purchase kosher food do so because they perceive it to be healthy, safe and better quality#173;#173;#173;-not because they adhere to the Jewish religious rules about food.But perception is not necessarily reality. Kosher rules for meat allow only certain animals slaughtered following specific guidelines; pork and rabbit are not considered kosher. Kosher rules also govern how food can be prepared and served; meat and dairy ingredients cannot be combined or prepared with the same equipment, for example. Processed foods must be produced under a rabbi's supervision.Foods may be certified by one of several different agencies, such as the Orthodox Union that indicates approval with an O-U mark. However, this certification does not mean that foods such as potato chips and zero-nutrient sugar-laden drinks are healthy.Whether or not meat processed following kosher law is less likely to contribute to food-borne bacterial illness has not been established. In fact, some may purchase kosher foods because of the philosophies that govern production, such as ethical treatment of animals.Of course kosher food can be a great part of a healthful diet, but don't assume that a kosher symbol automatically makes a food healthful.bull; Provided by the American Institute for Cancer Research. Learn more about the group and its New American Plate program at aicr.org.