Why coffee may reduce diabetes risk

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Coffee drinking has been linked with a reduced risk of diabetes, and now Chinese researchers think they may know why.

Three compounds found in coffee seem to block the toxic accumulation of a protein linked with an increased risk of type 2 diabetes.

''We found three major coffee compounds can reverse this toxic process and may explain why coffee drinking is associated with a lower risk of type 2 diabetes," says researcher Kun Huang, PhD, a professor of biological pharmacy at the Huazhong University of Science & Technology.

Previous studies have found that people who drink four or more cups of coffee a day have a 50% lower risk of getting type 2 diabetes.

The new study is published in the Journal of Agricultural and Food Chemistry.

Coffee and Diabetes Risk: Explaining Why It May Work

Type 2 diabetes is the most common type. In those who have it, the body does not have enough insulin or the cells ignore the insulin. The hormone insulin, made by the pancreas, is crucial to move glucose to the cells for energy.

Other researchers have linked the ''misfolding'' of a protein called hIAPP (human islet amyloid polypeptide) with an increased risk of diabetes. HIAPP is similar to the amyloid protein implicated in Alzheimer's disease, Huang says. When these HIAPP deposits accumulate, they can lead to the death of cells in the pancreas, Huang tells WebMD.

The Chinese researchers looked at three major active compounds in coffee and their effect on stopping the toxic accumulation of the protein:

"We exposed hIAPP to coffee extracts, and found caffeine, caffeic acid, and chlorogenic acid all inhibited the formation of toxic hIAPP amyloid and protected the pancreatic cells," Huang tells WebMD.

All three had an effect. However, caffeic acid was best. Caffeine was the least good of the three.

Those results suggest decaf coffee works, too, to reduce risk, Huang says. "In decaffeinated coffee, the percentage contents of caffeic acid and chlorogenic acid are even higher [than in regular coffee], whereas the level of caffeine is greatly reduced."

"We expect that decaffeinated coffee has at least equal or even higher beneficial effect compared to the regular caffeinated types," Huang says.

In patients who already have diabetes, he says, several studies suggest decaf is better for them than regular coffee.

The National Basic Research Program of China, the Natural Science Foundation of China, and other non-industry sources funded the research.

Coffee and Diabetes Risk: Perspective

Explaining the reduced risk of type 2 diabetes among coffee drinkers is an ongoing effort, according to Vivian Fonseca, MD, president for medicine and science for the American Diabetes Association. He is a professor of medicine at Tulane University, New Orleans.

He reviewed the study findings for WebMD. There are many possible mechanisms for explaining the link, he tells WebMD. The Chinese researchers, he says, ''have identified a fairly novel one."

However, he cautions that the study was done in the laboratory. "The next step would be to do studies in animals,'' he says. Next would be studies in people. The lab and animal findings don't always translate to human studies, he says.

Joe Vinson, PhD, a professor of chemistry at the University of Scranton who has researched coffee, also reviewed the study findings. "We know that coffee can help prevent type 2 diabetes and this may be just one of the ways it can do that," he says of the new research. "There may be more."

However, the concentrations of coffee compounds used in the study appear much higher than what the body would get from typical coffee consumption, Vinson says.

Vinson reports being a paid speaker at two National Coffee Association meetings.

Coffee and Diabetes Risk: Take-Homes

There are many measures to take to reduce diabetes risk, Fonseca says.

"Walk 30 minutes a day, lose 5% of your body weight if you are overweight," he says. "While doing that, if you drink a couple of cups of coffee it won't hurt you."

By Kathleen Doheny

Reviewed by Brunilda Nazario, MD

SOURCES:Cheng, B. Journal of Agricultural and Food Chemistry, Dec. 28, 2011.Kun Huang, PhD, professor of biological pharmacy, Huazhong University of Science & Technology, Wuhan, China.Vivian Fonseca, MD, president for medicine and science, American Diabetes Association; professor of medicine, Tulane University, New Orleans.Joe Vinson, PhD, professor of chemistry, University of Scranton, Scranton, Pa.

[kathylue]

I am certainly glad to hear this wonderful news because I drink coffee. It is my motivational juice! It brings a bear out of sleep and hibernation! Coffee drinkers, BEHOLD!!!

[tina322]

It must be true. My grandfather used to drink espresso coffee every single day, even in the evening. He had some kind of diabetes, he never was aware of it because he never visited s doctor, grandpa was a country living guy in a 3rd world country. Every time he was feeling dizzy, he took a spoon of sugar and blamed his worms he believed he had in his stomach. He lived to the age of 89 still riding his bicycle the day before he did his transition. WHAT WE BELIEVE IS WHAT MAKE US SICK. Read Doctor Bruce Lipton's "The Biology of Believe".

[amerilatino]

How happy to hear that decaf works at least just as well, because 4 or more cups of regular a day, and you'll croak from a heart attack or stroke within 5 years.

[Noval53]

If a cup of coffee triggers a heart attack, you're in pathetic shape already.

[swag]

As a Type I diabetic, this reads all like a mental masturbation exercise to me. Drink it because you enjoy it, not because you want to believe it's some snake oil remedy.

[finkfurst4]

How about coffee with 4 spoons of sugar?

[fedup12]

I love it when they find something I like is good for you!

I would do coffee intraveinously if I could :)

[finkfurst4]

If you really mean that then it would be easy - all you need is a syringe. However, it would kill you.

[baileyccc]

What a joke this report is, it is all diet and it is the starches that people eat.