Apples, Selenium May Lower Asthma Risk

From: Robina Suwol
Date: 13 Jan 2002
Time: 19:57:25
Remote Name:


NEW YORK, Dec 17 (Reuters Health) - A new UK study links intake of apples and the mineral selenium to a lower risk of asthma, suggesting 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 have speculated that antioxidants may protect lung health, including lowering the risk of asthma. But studies on antioxidants like vitamins C and E have produced conflicting results. And even less is known about other antioxidants, such as plant compounds called flavonoids and trace minerals like selenium, according to Dr. Seif O. Shaheen and colleagues. To see how dietary antioxidants affect asthma risk and severity, Shaheen's team 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, asthma risk declined, according to findings published in a recent issue of the American Journal of Respiratory and Critical Care Medicine. 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. Red wine intake was associated with a reduction in the severity of asthma, according to Shaheen and colleagues from King's College in London and the University of Southampton. ... [Am. J. Respir. Crit. Care Med., Volume 164, Number 10, November 2001, 1823-1828 Dietary Antioxidants and Asthma in Adults Population-based Case-Control Study SEIF O. SHAHEEN, JONATHAN A. C. STERNE, RACHEL L. THOMPSON, CHRISTINA E. SONGHURST, BARRIE M. MARGETTS, and PETER G. J. BURNEY Department of Public Health Sciences, King's College, Capital House, London; and Institute of Human Nutrition, University of Southampton, Southampton, United Kingdom A protective role for dietary antioxidants in asthma has been proposed. However, epidemiological evidence to implicate antioxidant vitamins is weak, and data on the role of flavonoid-rich foods and antioxidant trace elements are lacking. We carried out a population-based case-control study in South London, UK, to investigate whether asthma is less common and less severe in adults who consume more dietary antioxidants. Participants were aged 16-50 yr and registered with 40 general practices. Asthma was defined by positive responses to a standard screening questionnaire in 1996, and complete information about usual diet was obtained by food frequency questionnaire from 607 cases and 864 controls in 1997. After controlling for potential confounding factors and total energy intake, apple consumption was negatively associated with asthma (odds ratio [OR] per increase in frequency group 0.89 [95% confidence interval [CI]: 0.82 to 0.97]; p = 0.006). Intake of selenium was also negatively associated with asthma (OR per quintile increase 0.84 [0.75 to 0.94]; p = 0.002). Red wine intake was negatively associated with asthma severity. The associations between apple and red wine consumption and asthma may indicate a protective effect of flavonoids. The findings for dietary selenium could have implications for health policy in Britain where intake has been declining. -- Gary N. Greenberg, MD MPH Sysop/Moderator Occ- Env-Med-L MailList Duke Occupat, Environ, Int & Fam Medicine OEM-L Maillist Website:

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