The results of a nearly 30-year follow-up study show that women who drink alcohol three times a week have a higher risk of breast cancer than those who do not drink alcohol at all. The study, published in the Journal of the American Medical Association on the 2nd, targeted 100,000 healthy American female nurses between the ages of 30 and 55, mostly Caucasians. The study began in 1980 and ended in 2008. Citing the findings, the Associated Press reported that the study subjects drank alcohol an average of three to six times a week and had a 15 percent higher chance of developing breast cancer than non-drinkers. Among women over the age of 50, the chance of developing breast cancer was 2.38 percent, but light drinking increased the number of breast cancer cases by four per 1,000 women. Studies have reported that drinking an additional 10 grams of alcohol per day is associated with a 10 percent increase in the chance of developing breast cancer. A 12-ounce (about 340 grams) bottle of beer or a 4-ounce (about 113 grams) glass of wine contains about 10 grams of alcohol.