Men and women age 55 and younger who drank four or more cups of coffee a day had a 50 percent increased mortality risk from all causes, UPI cited U.S. researchers as saying. Study co-author Dr. Carl J. Lavie of the Department of Cardiovascular Diseases, Ochsner Medical Center in New Orleans said the latest National Coffee Drinking Study found 60 percent of U.S. adults drink coffee every day, consuming on average just over three cups a day. The research team investigated the effect of coffee consumption on death from all causes and deaths from cardiovascular disease in the Aerobics Center Longitudinal Study. From 1979 and 1998, the investigators examined a total of 43,727 participants -- 33,900 men and 9,827 women. During the 17-year median follow-up period there were 2,512 deaths -- 87 percent men, 12 percent women -- 32 percent of these caused by cardiovascular disease. "Significantly, the results did not demonstrate any association between coffee consumption and all-cause mortality among older men and women," said senior investigator Steven H. Blair of the University of South Carolina. "It is also important to note that none of the doses of coffee in either men or women whether younger or older had any significant effects on cardiovascular mortality." Younger men had a higher mortality even at lower consumption and this became significant at about 28 cups per week at which there was a 56 percent increase in mortality from all causes. Younger women who consumed more than 28 cups of coffee per week had a greater than two-fold higher risk of all cause mortality than those who did not drink coffee, the study said. The investigators suggested younger people should avoid heavy coffee consumption of more than 28 cups a week or four cups in a typical day. However, they emphasized further studies were needed in different populations to assess details regarding the effects of long-term coffee consumption and changes in coffee consumption over time on all-cause and cardiovascular disease mortality.