Quit Smoking: 10 Overlooked Reasons (cont.)

Colic affects an estimated 5%-28% of babies born in Western countries. Its causes have been attributed to everything from exposure to cow's milk proteins to feeding difficulties to maternal depression or anxiety.

Tobacco smoke appears to raise levels of a gut hormone called motilin in the blood and intestines. Motilin increases the contractions of the stomach and intestines, increasing the movement of food through the gut. "Higher-than-average motilin levels are linked to elevated risks of infantile colic," the researchers write in the October issue of the journal Pediatrics.

An Increased Risk of Impotence

Guys concerned about their performance in the bedroom should stop lighting up, suggests a study that linked smoking to a man's ability to get an erection. The study of nearly 5,000 Chinese men showed that men who smoked more than a pack a day were 60% more likely to suffer erectile dysfunction, compared with men who never smoked cigarettes.

Overall, 15% of past and present smokers had experienced erectile dysfunction, more commonly known as impotence. Among men who had never smoked, 12% had erection problems, according to the study, presented last year at the American Heart Association's annual Conference on Cardiovascular Disease Epidemiology and Prevention in Miami.

Blindness: Smoking Raises Risk of Age-Related Macular Degeneration

Smokers are four times more likely to become blind because of age-related macular degeneration than those who have never smoked. But quitting can lower that risk, other research shows.

Age-related macular degeneration is a severe and progressive condition that results in loss of central vision. It results in blindness because of the inability to use the part of the retina that allows for 'straight-ahead' activities such as reading, sewing, and even driving a vehicle. While all the risk factors are not fully understood, research has pointed to smoking as one major and modifiable cause.

"More than a quarter of all cases of age-related macular degeneration with blindness or visual impairment are attributable to current or past exposure to smoking," Simon P. Kelly, MD, an ophthalmic surgeon with Bolton Hospitals in the U.K, wrote in the March 4, 2004 issue of the BMJ. He came to his conclusion after reviewing three studies involving 12,470 patients.

But other studies show that former smokers have an only slightly increased risk of age-related macular degeneration, compared with never smokers, he writes.

Rheumatoid Arthritis: Genetically Vulnerable Smokers Increase Their Risk Even More

People whose genes make them more susceptible to developing rheumatoid arthritis are even more likely to get the disease if they smoke, say Swedish researchers.