Q. I heard recently that eating more fiber is good for the lungs. Is that just marketing hype?

A. It may not be. A recent study of almost 12,000 middle-aged adults suggests that eating more fiber is associated with a slower rate of lung function decline. The study, reported in the American Journal of Epidemiology, found that those with the highest daily fiber intake (27 g per day) had better lung function and were less likely to have COPD than those who had the lowest fiber intake (9.5 g on average). Significant lung benefits were associated with consumption of fiber in cereal and, to a lesser degree, fruit, but not vegetables.

The benefits may be due to the fiber's antioxidant properties. Although most studies of nutrition and lungs have focused on antioxidant vitamins, this is the first major study to suggest that eating more fiber may protect your lungs.

There are many other reasons to increase your fiber intake. Fiber appears to reduce the risk of developing a variety of health conditions, such as heart disease, diabetes, diverticular disease, and constipation. The easiest way to boost your fiber intake is to eat bran cereal: One half cup of 100% bran ready-to-eat cereal can provide as much as 10 g of fiber. Add some fruit to increase your fiber count: One half cup of raspberries has 4.6 g and a medium banana has 3 g. If you are not used to eating fiber, increase your consumption gradually to reduce the risk of gastrointestinal side effects.