Decaf, but not caffeinated, coffee may cause an increase in harmful low-density cholesterol, but may also be beneficial to some overweight people, according to a new study.
The findings, reported Wednesday at the American Heart Association’s annual scientific meeting in Dallas, indicate that decaf coffee seems to increase specific types of blood fat that drive the production of low-density lipoproteins, or “bad” cholesterol, but also seems to boost production of high-density “good” cholesterol in people who are overweight.
The research is the latest in a long line of scientific studies that have considered whether coffee drinking contributes to heart disease, with some finding links, but others concluding there’s no harm from most java consumption.
Dr. Robert Superko, lead author of the study and chairman of preventive cardiology at the Fuqua Heart Center in Atlanta, said the problem with many coffee and health studies has been that they looked only at people’s established coffee-drinking habits and tried to associate them with some disease risk pattern.
His team sought to test coffee in more controlled circumstances. “Our study randomized subjects to a specific type and amount of coffee consumption, brewed in a standardized manner, just like a drug study,” Superko said.
Researchers in the National Institutes of Health-funded study assigned 187 volunteers to three groups: no coffee, three to six cups a day of regular or three to six cups of decaf daily. The coffee drinkers got identical coffee makers and pre-measured bags of Maxwell House, and were required to drink it without cream or sugar. Participants also kept food diaries for a week at the beginning and end of the study to determine if eating habits influenced the results.
After three months, there were no significant changes among the three groups in levels of blood glucose, blood pressure or other major risk factors. But the decaf drinkers did have slightly higher levels _ 8 percent to 18 percent _ of fatty acids, which are the fuel in the blood for LDL cholesterol, and about 8 percent higher levels of apolipoprotein (ApoB), a protein associated with LDL levels.
Superko said that while he doubts there’s a health threat from coffee for most people drinking a couple of cups of any kind of coffee a day, the study did detect a difference in how a steady decaf diet affected people who are overweight. Those with a body mass index of more than 25 increased their HDL cholesterol (the good type) by about 50 percent during the study, while decaf drinkers who were not considered overweight saw HDL levels drop by about 30 percent.
“So those who are overweight and have low levels of HDL but normal levels of ApoB might consider the potential benefit of drinking decaf over caffeinated coffee,” the researcher said. “It’s not a simple story of one coffee is good, one coffee is bad.”
Officially, the Heart Association says the question of whether high caffeine intake raises heart-disease risk is still open, but advises that moderate coffee drinking, of one or two cups a day, doesn’t seem harmful. Then again, coffee drinkers in the United States consume an average of about three cups a day.
The study also adds to the notion that there’s more to the health effects of coffee than just caffeine. Coffee beans contain several hundred different substances, and recent studies have found similar effects on blood pressure, for instance, regardless of whether test subjects drank regular or decaf.
Superko notes that while most regular coffee is made from Arabica beans, decaf uses Robusta coffee beans that are more flavorful, and somewhat higher in some types of fat, to make up for flavonoids and other ingredients that give coffee flavor but are largely washed out in decaffeinating the beans.
On the Net: http://www.americanheart.org
(Contact Lee Bowman at BowmanL(at)SHNS.com)