Nothing jolts the body into action in the morning like a strong cup of coffee. However, people concerned about heart health may want to limit their intake, a new trial suggests.
Several oily coffee-bean components can elevate cholesterol in a person's blood. Although the paper filters of drip coffeemakers largely eliminate those oils (SN: 2/4/95, p. 72), drinking even filtered coffee can increase blood concentrations of the amino acid homocysteine, another risk indicator (SN: 1/11/97, p. 22).
Norwegian scientists have now investigated these coffee-borne factors in a 6-week trial of 191 nonsmokers. All had been downing an average of 5 cups of coffee daily.
Benedicte Christensen of Ullevl University Hospital in Oslo and her colleagues randomly assigned equal numbers of these people to give up coffee altogether, to limit their intake to 1 to 3 cups of filtered coffee per day, or to drink at least 4 cups daily. At the beginning, middle, and end of the trial, Christensen's team measured cholesterol and other heart-risk indicators in the participants' blood.
Only those who went cold turkey on coffee showed a significant change–a drop–in two key indicators, Christensen's team reports in the September American Journal of Clinical Nutrition.
During the trial, blood cholesterol fell an average of 5 percent in the no-coffee group; homocysteine fell 12 percent.
According to the researchers, calculations from previous studies have indicated that a cholesterol drop of this magnitude could cut the incidence of heart disease by about 15 percent. The observed homocysteine drop corresponds to a 10 percent decrease in heart risk.
So far, studies of coffee drinking and heart attacks have had conflicting results. The new study doesn't directly link coffee to disease. Even so, Christensen speculates that java could be part of the complex equation behind heart disease, including other risk factors and a person's overall health.
Department of Medical Genetics
Ullevl University Hospital
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