Women's Health is reporting today on the results of a new study, published yesterday in the journal, Stroke. The findings suggest that the consumption of green tea or coffee on a daily basis may lower the risk of suffering a stroke by approximately 20 percent, along with an even greater risk reduction for a specific type of stroke.
Japanese researchers studied approximately 83,000 men and women aged 45 to 74, compiling data on the amount of coffee and/or green tea they consumed on a daily basis. During a 13 year follow-up, researchers collected data from hospital records, death certificates, including specific data about deaths from heart disease and stroke among the study participants.
The study results showed that people who consumed at least one cup of coffee daily lowered their risk of stroke by approximately 20 percent. Additionally, a comparison between green tea drinkers and those who rarely consumed it, found that people who consumed two to three cups daily had a 14 percent lower stroke risk. Those who consumed at least four cups had a 20 percent lower risk for having a stroke.
Of even more significance was the conclusion that the risk for having a hemorrhagic stroke, the type of stroke that involves the bursting of a blood vessel in the brain, was lowered to a whopping 32 percent in people who consumed at least one cup of coffee or two cups of green tea on a daily basis.
Lead researcher, Doctor Yoshihiro Kobuko, chief doctor in the Department of Preventive Cardiology at Osaka's National Cerebral and Cardiovascular Center, said, "The regular action of daily drinking of green tea and coffee is a benefit in preventing stroke. If you cannot readily improve your lifestyle, try to prevent stroke by drinking green tea every day."
Kobuko explained that although the reasons that coffee and green tea lower the risk of stroke, he believes that certain properties contained in both may keep blood from clotting. Green tea has catechins, a property with an anti-inflammatory and antioxidant effect. Kobuko also felt that the chlorogenic acid found in coffee may lower stroke risks by lowering the risks for the development of type 2 diabetes. Additionally, the caffeine in coffee can impact blood pressure and cholesterol levels, and may cause changes in one's sensitivity to insulin, affecting blood glucose levels.
Doctor Ralph Sacco, past president of the American Heart Association and chairman of neurology at the University of Miami Miller School of Medicine, took a cautionary stance, saying, "Such association studies are still limited in the ability to tell whether it is some ingredients in the coffee or tea or some other behavior common to coffee and tea drinkers that is driving the protective effects. There have been other studies, however, that have suggested some beneficial effects of coffee and tea on brain health, so the evidence is accumulating that there are some important simple dietary ways we can improve our health."