Coffee, Tea or Stroke?

Stroke risk may be reduced by regular consumption of coffee or green tea

Enjoy coffee or green tea in the morning? Now you may have more reason to pour a cup. Although there are still conflicting opinions, a huge study found these beverages may be stroke reducers.

Over the past few years, scientists have been debating the advantages of drinking coffee and tea.

In fact, previous research from Harvard Medical School in February revealed that coffee and tea did not have an effect on stroke reduction.

But a new study found that coffee and green tea may lower stroke risk, especially if they are part of a regular diet.

Eat foods rich in antioxidants.

Yoshihiro Kokubo, MD, Division of Preventive Cardiology at Japan’s National Cerebral and Cardiovascular Center in Osaka, led the investigation, which asked 83,269 Japanese adults about their green tea and coffee drinking habits.

Participants were between the ages of 45 and 74 and almost evenly divided in terms of gender. All were free from cancer and cardiovascular disease.

Over the course of 13 years, Dr. Kokubo and his team reviewed participants’ hospital medical records and death certificates, collecting data about heart disease, strokes and causes of death.

Overall, researchers found that the more green tea and coffee people drank, the lower their stroke risk. Some of the study highlights included:

  • People who drank at least one cup of coffee daily had about a 20 percent lower risk of stroke compared to those who rarely drank it.
  • People who drank two to three cups of green tea daily had a 14 percent lower risk of stroke, and those who had at least four cups had a 20 percent lower risk, compared to those who rarely drank it.
  • People who drank at least one cup of coffee or two cups of green tea daily had a 32 percent lower risk of intracerebral hemorrhage, compared to those who rarely drank either beverage. Intracerebral hemorrhage happens when a blood vessel bursts and bleeds inside the brain. About 13 percent of strokes are hemorrhagic.

Initial study results did not show benefits of drinking coffee. The authors discovered that drinking more than two cups of coffee daily was linked to increasing rates of coronary heart disease. But after factoring in the effects of cigarette smoking, investigators did not find this link. This finding underscored smoking’s negative impact on heart health and stroke.

“The regular action of drinking tea [and/or] coffee largely benefits cardiovascular health because it partly keeps blood clots from forming,” said Dr. Kokubo.

The study suggests that chlorogenic acid in coffee cuts stroke risks by lowering the chances of developing type 2 diabetes. An antioxidant in green tea called catechins has an anti-inflammatory effect and this may reduce stroke risk.

Deborah Gordon, MD, an integrative physician at Madrona Homeopathy in Ashland, Oregon, and at, pointed out some of the uncertainty surrounding these beverages.

Dr. Gordon told dailyRx News, “The confusion in my clinical practice has stemmed from some people's sensitivity to caffeine. A significant number of people—of all ages, but most prominently past the age of 40—are sensitive to caffeine, exhibiting irregularities of their heart rhythm, sleep disturbances or excessive gastrointestinal stimulation."

"On the other hand," she added, "coffee and tea—especially green tea—are excellent sources of antioxidants. With this additional information about reducing stroke risk, I will continue to screen for caffeine sensitivity and then proceed to recommend two to three cups a day of either beverage. Once the caffeine is removed, there really is not a down side, but various health benefits to the habit.”

The study was published in March in Stroke: Journal of the American Heart Association. The research was supported by Grants-in-Aid for Cancer Research and the Third-Term Comprehensive Ten-Year Strategy for Cancer Control from the Ministry of Health, Labour and Welfare of Japan.