Quitting smoking lowers cataract risk slightly

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Quitting smoking lowers cataract risk slightly

By Suzanne Rostler

NEW YORK, Jan 07 (Reuters Health) - Quitting smoking over the long term

can lead to a modest reduction in the risk of developing cataracts, new

research suggests.

Investigators found that individuals who had quit smoking for at least

25 years were 20% less likely to undergo surgery to remove cataracts

than current smokers, regardless of other known risk factors such as

higher body mass index, diabetes and the intake of certain nutrients

that may be protective.

The findings " suggest that any healing from damage due to cigarette

smoking occurs at a very modest pace, and they emphasize the importance

of never starting to smoke or quitting early in life, " according to Dr.

June M. Weintraub and colleagues from Harvard School of Public Health in

Boston, Massachusetts.

Smoking is known to increase a person's risk of developing cataracts, a

leading cause of blindness, in old age. According to the report in the

January issue of the American Journal of Epidemiology, atoms known as

free radicals found in cigarette smoke and other air pollutants can

cause a type of damage known as oxidative stress to the lens of the eye.

" Not only does smoking increase oxidative stress, but the ability to

counter this oxidative stress is diminished by smoking, " Weintraub, who

now works as an epidemiologist at the San Francisco Department of Public

Health, said in an interview. " So with smoking, there is increased

stress and a reduced ability to fight the stress. "

Quitting smoking may therefore slow the progression of cataracts by

removing oxidative stress, by boosting antioxidant activity, or both,

the report indicates.

To investigate whether kicking the habit had any effect on cataract

risk, the team of researchers reviewed medical information on more than

100,000 male and female health professionals participating in two major

US health studies that began in 1976 and 1986.

Smokers had a higher risk of cataracts and the risk rose in tandem with

the number of cigarettes smoked daily. Former smokers were able to

decrease their risk over time, with the likelihood of developing

cataracts declining with the number of years they had quit.

However, the risk reduction was not enough to equal the risk among

people who had never smoked, who were 36% less likely to develop

cataracts than current smokers.

" Our finding that the excess risk of cataract extraction persists after

quitting smoking and only moderately decreases with years since quitting

provides further support for the hypothesis that smoking causes

irreversible damage to the lens, " Weintraub and colleagues conclude.

SOURCE: American Journal of Epidemiology 2002;155:72-79.