Scientists say green tea and coffee, if made a regular part of the diet, could benefit the heart, according to research conducted in Japan and published in the US. Green tea and coffee may help lower your risk of having a stroke, especially when both are a regular part of your diet, according to research published in Stroke: Journal of the American Heart Association. "This is the first large-scale study to examine the combined effects of both green tea and coffee on stroke risks," said Yoshihiro Kokubo, lead author of the study at Japan's National Cerebral and Cardiovascular Centre. "You may make a small but positive lifestyle change to help lower the risk of stroke by adding daily green tea to your diet." They found that the more green tea or coffee people drink, the lower their stroke risks, reports Science Daily. "The regular action of drinking tea and coffee, largely benefits cardiovascular health because it partly keeps blood clots from forming," Kokubo said. Tea and coffee are the most popular drinks in the world after water, suggesting that these results may apply in other countries too. It's unclear how green tea affects stroke risks. A compound group known as catechins may provide some protection. Catechins have an antioxidant anti-inflammatory effect, increasing plasma antioxidant capacity and anti-thrombogenic (anti-clotting) effects. Some chemicals in coffee include chlorogenic acid, thus cutting stroke risks by lowering the chances of developing type 2 diabetes.Further research could clarify how the interaction between coffee and green tea might help further lower stroke risks, Kokubo said.