Coffee May Cut Type 2 Diabetes Risk
But Don't Up Your Java Intake Just Yet
Jan. 5, 2004 -- Coffee drinkers seem to have a lower risk of diabetes, a new study suggests. But don't take this news as carte blanche to drink more coffee, researchers caution.
"It is too premature to recommend increased coffee drinking as a means to prevent type 2 diabetes," writes lead researcher Frank B. Hu, MD, PhD, with the Harvard School of Public Health. His study appears in the current Annals of Internal Medicine.
Indeed, the evidence on coffee consumption has been mixed and controversial: Some studies have found blood pressure spikes and more heart-related deaths in coffee drinkers, and caffeine may interfere with insulin's actions in the body.
But other, longer-term studies have uncovered hints of coffee consumption's benefit: the more coffee consumption, the lower the risk of type 2 diabetes.
Also, caffeine stimulates thermogenesis -- the burning of calories -- and may increase metabolism, Hu explains.
But how does a person's coffee intake during the day affect diabetes-related processes?
To answer that question, Hu and his colleagues looked at two large studies involving 126,210 men and women. All had completed dietary and lifestyle surveys every two years for 12 to 18 years.
There were 1,333 new cases of type 2 diabetes in men and 4,085 cases in women, reports Hu.
They found that:
- Coffee intake lowered the risk of type 2 diabetes, and the lowering was independent of a person's age, obesity, and other lifestyle factors that typically increase risk.
- Drinking more coffee had better effects: Those who drank six or more cups per day had the lowest risk of having type 2 diabetes compared with those who drank less coffee.
- Decaffeinated drinks and other caffeine sources had lesser effects on diabetes risk. While decaffeinated coffee seemed to offer some protection, decaffeinated tea did not.
Caffeine may stimulate muscles to burn fat and sugar more efficiently and could trigger the breakdown of fat in other tissue as well, Hu explains. Some studies have shown that caffeine does help with weight loss, he adds.
Also, coffee contains many other ingredients that could have beneficial effects on preventing type 2 diabetes -- such as potassium, niacin, and magnesium, as well as antioxidants.
In fact, Hu says he believes the blood-pressure spikes found with caffeine may be short-term and that the body naturally adjusts to the jolt.
Though his study suggests long-term beneficial effects, it is too preliminary to prove a cause-effect relationship between caffeinated coffee intake and lower type 2 diabetes risk, Hu says. Don't up your java intake -- especially if you already have diabetes or heart disease.