Coffee, Heart-disease Debate Brewing

March 08, 1985|By Jon Van, Science writer.

Drinking 2 1/2 to 3 cups of coffee a day may increase a middle-age man`s risk of heart disease, a study published in Friday`s Journal of the American Medical Association suggests.

Previously, foreign studies have linked coffee consumption with elevated levels of cholesterol in the blood, but this study, conducted at Stanford University, is the strongest link between coffee and cholesterol in Americans. The National Coffee Association termed the Stanford study as ``not a significant contribution to the extensive body of literature on coffee intake and cardiovascular disease.`` Most studies, the group said, haven`t found a link between coffee drinking and heart attacks.

The Stanford study followed closely the dietary habits of 77 healthy men 30 to 55 years old for three days. Researchers found no effect on cholesterol levels in men drinking 2 cups of coffee or less daily, but above 2 1/2 cups cholesterol levels were elevated.

The researchers considered several variables, including stress, smoking habits and use of coffee creamers to see if such factors might explain the cholesterol differences associated with coffee consumption. By statistically eliminating the effects of these factors, they found the coffee-cholesterol link actually was strengthened.

Cholesterol is a general term for fatty or lipid materials and proteins that circulate in the blood. Some kinds of cholesterol or lipoproteins are thought to clog arteries while other kinds do not.

It was low-density lipoproteins and apolipoprotein B, two kinds of cholesterol most associated with heart disease, that increased the most in heavy coffee drinkers.

``The significant association observed between coffee and lipoprotein concentrations in these men could not be attributed to effects caused by age, cigarette smoking, adiposity (obesity), aerobic fitness or other dietary factors or to any of the psychological variables,`` the researchers said.

Still, to be absolutely certain coffee directly causes cholesterol to increase, further studies are needed, the researchers cautioned. Those studies will also address what components of coffee, such as caffeine, might be responsible. The Stanford study concerned men who drank mostly regular coffee made from grounds, with few using instant coffee, decaffeinated coffee or tea. Earlier U.S. studies may have missed the coffee-cholesterol link, the researchers said, because they failed to spot heavy coffee drinkers. People who drink less than 2 1/2 cups don`t show any association with cholesterol.

The results of the Stanford research, funded by the federal National Heart, Lung and Blood Institute, support a study of 47,000 men and women published in February`s American Journal of Cardiology.