Even Two Cups Coffee A Day Can Be Dangerous For People With Severe Hypertension

Switch to green tea. Drinking two or more cups of coffee daily may double the risk of cardiovascular disease death in people with severe hypertension, warn Japanese researchers.

If you have severe high blood pressure (160/100 mm Hg or higher), it is advisable to avoid drinking coffee. A study from Japan has cautioned that excessive coffee consumption can increase risk of death from cardiovascular disease in people with severe high blood pressure. According to the study recently published in the Journal of the American Heart Association, drinking two or more cups of coffee daily may double the risk of death in these patients.

However, the researchers did not see one cup of coffee a day and daily green tea consumption associated with increased risk of death due to cardiovascular disease across any blood pressure categories.

This is surprising, as both coffee and green tea contain caffeine. As per the FDA estimates, an 8-ounce cup of green or black tea contains 30-50 milligrams of caffeine, while an 8-ounce cup of coffee contains about 80 to 100 milligrams. The researchers believe the presence of polyphenols in green tea may explain its benefits.

Side effects of drinking too much coffee

If taken in moderation, coffee is actually good for health. Previous studies have linked one cup of coffee a day to reduced risk of heart attacks or strokes, as well as found beneficial for heart attack survivors in lowering their risk of death. There are also studies that say drinking coffee regularly may help lower the risk of Type 2 diabetes, some cancers, and depression. However, it is not clear if this beneficial effect is from the caffeine or something else in coffee. On the contrary, too much coffee is associated with high risk of increased blood pressure, anxiety, heart palpitations and sleep problems.

The new study, which included more than 18,600 Japanese men and women, found drinking 2 or more cups of coffee daily associated with increased cardiovascular disease mortality among people with severe hypertension. During the study period, nearly 19 years, 842 cardiovascular-related deaths were documented. Among people whose blood pressure was 160/100 mm Hg or higher, those who drink two or more cups of coffee a day were twice as likely to die due to cardiovascular disease as compared to those who did not drink coffee at all.

Based on their findings, the researchers have advised people with severe hypertension or high blood pressure to avoid drinking excessive coffee as they are more susceptible to the harmful effects of caffeine.

People who drink more coffee also smoke and drink more

Younger people, current smokers and drinkers were mostly likely to drink coffee more. People with more frequent coffee consumption also eat fewer vegetables, have higher total cholesterol levels and lower systolic blood pressure regardless of their blood pressure measurement.

The research team included Hiroyasu Iso, director of the Institute for Global Health Policy Research, Bureau of International Health Cooperation, National Center for Global Health and Medicine in Tokyo, Japan, and professor emeritus at Osaka University.