Eating apples and the mineral selenium may lower one's risk of asthma, which suggests that certain antioxidants may protect the lungs from disease.

Antioxidants help neutralize damaging forms of oxygen that arise from normal metabolism.

These free radicals are unstable compounds that can damage cells and are thought to contribute to chronic disease.

Researchers surveyed nearly 1,500 UK adults about their eating habits during the previous year. They focused particularly on intakes of fruits and vegetables, flavonoid-rich foods like apples, onions, tea and red wine, antioxidant vitamins, and trace elements that act as antioxidant enzymes -- such as selenium, zinc and copper.

The investigators found that people who ate at least two apples per week faced a 22%- to 32% lower asthma risk than those who ate fewer.

And as selenium intake increased. Participants with the highest intakes -- 54 to 90 micrograms a day -- were only about half as likely to have asthma as those who consumed the least selenium, about 23 to 30 micrograms daily. The US recommended daily intake for selenium is 55 micrograms.

The researchers speculate that certain subtypes of flavonoids may be key in this protection since other flavonoid-containing foods did not affect asthma risk or severity. Or, in the case of apples, different compounds altogether may be at work.

As for selenium, they suggest that part of the blame for the UK's rising asthma rates may rest in the nation's declining selenium intake. The researchers note that selenium may protect against asthma by suppressing airway inflammation.

Selenium is found in foods such as Brazil nuts and walnuts, and beef.

American Journal of Respiratory and Critical Care Medicine 2001;164:1823-1828

Dr. Mercola's Comments:

As the other article in this issue states, these improvements were noted in a review of people who obtained vitamin C from foods, NOT from supplements. Many will use these types of studies to justify regular use of vitamin C supplements to obtain similar benefits. While it is clear that vitamin C as a supplement has some benefits, it may not be as profound as obtaining the vitamin C from whole foods. It is so easy to rely on taking supplements rather than whole foods, but if one is persistent and follows the eating plan one will start to reap the harvest of good health. Selenium maybe an exception however, as many trace elements are particularly difficult to obtain from whole food sources unless high quality organic farmers raise the food. Taking a high quality selenium supplement may seem reasonable. Related Articles: Vitamin C One Key to Good Health Vitamin C blocks Exercise-Inducted Asthma Antioxidants: The Good, the Bad and the Evil Vitamin C Levels and Vegetables May Lower Stroke Risk Last Interview With Dr. Pauling