LONDON, Jul 09 (AP) — Drinking at least one cup of tea a day could cut the risk of heart attack by 44 percent, according to new research presented yesterday.
The study by Dr. Michael Gaziano, a heart specialist at the Harvard Medical School-affiliated Brigham and Women’s Hospital in Boston, shows that tea contains powerful amounts of flavonoids — vitamin-like nutrients that make blood cells less prone to clots, which can cause heart attacks.
Flavonoids also are one of the most powerful antioxidants, which offset the damaging effects of oxygen in the body, such as fatty deposits in the arteries. Scientists have recently become excited about the potential benefits of flavonoids, which number about 4,000 and are also found in fruits, vegetables and are famously connected to the heart-healthy effects of red wine.
While earlier studies have suggested that tea-drinking could be good for the heart, the latest findings, presented Thursday at a Royal Society of Medicine conference in London, are the most comprehensive and indicate the most dramatic effect.
Gaziano found that people who drank one or more cups of tea a day slashed their risk of heart attack by 44 percent, compared with those who did not drink tea.
“This is, in my view, quite an astonishing outcome,” said Dr. Catherine Rice-Evans, an antioxidant researcher at King’s College, London, who was not connected with the study. “These are very exciting results.”
But the study did not compare the benefits of one cup versus two, three or four, and the question of how much tea to drink, and how strong it should be brewed for the greatest benefit is still open to debate.
John Folts, a University of Wisconsin heart specialist who studies the effects of flavonoids on the heart and was not involved in the study, said he thinks it would take more than one cup of tea a day. His studies on dogs have indicated that six cups of tea daily are needed to prevent a blood clot in the coronary artery.
Gaziano’s study examined 340 men and women who had suffered heart attacks and matched them by age, sex and neighborhood with people who had never had a heart attack. It then investigated their coffee- and tea-drinking habits over the course of a year.
The study involved regular tea from black tea leaves, as opposed to green or herbal teas. Scientists say black tea contains more powerful flavonoids than green tea, while herbal teas are not known to contain any flavonoids.
Other studies have shown that it doesn’t matter if milk, sugar or lemon are added to the tea. There also is no difference between drinking it hot or cold, or preparing it with loose tea leaves, tea bags or granulated crystals, said Dr. Paul Quinlan, a biochemist who heads the Brook Bond tea company’s health research unit.
Few of the study subjects drank one beverage exclusively, so they were categorized by their strong preferences. The study was adjusted for factors that could have skewed the results, such as smoking, exercise, alcohol intake and family history of heart trouble. Total calories consumed, intake of fatty foods and body mass index — which compares the girth of people of different heights to determine obesity — was about the same across the board.
Scientists have not compared the flavonoid benefits of tea with those of red wine, made famous by research showing that the French, with red wine as a staple, have lower rates of heart disease despite their penchant for high-fat food. However, Quinlan warned that tea is only part of a regimen for cutting heart attack risk and should not be seen as a substitute for eating fruits and vegetables, giving up smoking, cutting fat intake or other heart-healthy habits.
The study, which was paid for by the U.S. National Heart, Lung and Blood Institute, also found that coffee had no effect on heart attacks, regardless of whether it was decaffeinated.
— Associated Press (2002)