A recent study investigated the effect of green tea and coffee on mortality risk among people with type 2 diabetes. The researchers found that drinking two or more cups of coffee and four or more cups of green tea each day was associated with a 63% lower all-cause mortality.

In the United States, more than 1 in 10 adults have type 2 diabetes. Globally, the disease affects an estimated 422 million people.

Diabetes increases the risk of a range of health conditions, including cancer, bone fractures, dementia, and circulatory diseases.

Although medications can significantly reduce the health risks associated with diabetes, experts also consider lifestyle changes one of the best ways to control type 2 diabetes. These include eating a healthful diet, doing more physical activity, and stopping smoking, if a smoker.

Coffee, green tea, and diabetes

Over the years, many scientists have investigated the potential health benefits of green tea. Some studies have shown a link between the consumption of green tea and a lower risk of developing diabetes.

Other scientists have shown that drinking green tea might improve glucose control and insulin sensitivity. However, until now, few researchers have examined how green tea might benefit people with type 2 diabetes, specifically.

Coffee has also enjoyed a great deal of scientific attention over the years. There is some evidence that a high coffee consumption leads to a lower risk of type 2 diabetes compared with a low consumption.

Beyond diabetes, there is some evidence that coffee consumption is linked with a reduced risk of mortality. However, as with green tea, few scientists have investigated this association in individuals who have diabetes.

Although there are inherent difficulties in studying the effects of specific foods on health conditions, evidence that green tea and coffee might benefit certain aspects of health is mounting.

Recently, researchers from Kyushu University, Fukuoka Dental College, and Hakujyuji Hospital, all in Japan, set out to investigate the effect of coffee and green tea on the death risk of people with diabetes. They recently published their results in BMJ Open Diabetes Research & Care.

The findings

Individuals who drank more than one cup of green tea or coffee per day had lower odds of dying from any cause in comparison with those who drank neither. The lowest odds were associated with drinking higher quantities of both green tea and coffee.

Even after accounting for variables that might have influenced their analysis, the authors conclude:

“[H]igher green tea and coffee consumption was significantly associated with decreased all-cause mortality in [people] with type 2 diabetes.”

The authors explain that “the combination of higher green tea and coffee consumption significantly reduced all-cause mortality risk by 63%” over a median follow-up period of 5.3 years.

Looking at coffee alone, the researchers found that drinking two or more cups per day was associated with 41% lower odds of dying during follow-up.

When calculating the odds of dying among green tea-drinkers, they found that drinking four or more cups each day was associated with 40% lower odds.

However, drinking both beverages each day produced the largest effects:

  • two to three cups of green tea plus two or more cups of coffee — 51% lower
  • four or more cups of green tea plus one cup of coffee — 58% lower
  • four or more cups of green tea and two or more cups of coffee — 63% lower

Medical reference: Medical News Today