London Free Press

Don’t peel those tangerines. A compound found mainly in the pith of the fruit has proven remarkably successful in preventing a range of health problems in mice, from type 2 diabetes to heart disease.

Researchers at the Robarts Institute at the University of Western Ontario have linked flavonoid in tangerines called Nobiletin with disease prevention in mice in a study published in the journal Diabetes.

Two groups of mice were fed a diet designed to make them unhealthy — think of it as fast food for rodents, chock full of fat and sugar.

But one group was also given a powdered form of purified Nobiletin and the results were startling.

Those not getting the supplement became obese, accumulated high levels of insulin and glucose in their blood and developed a fatty liver, type 2 diabetes and liver and atherosclerosis, a condition that underlies most strokes and heart disease.

None of those conditions developed in the group of mice that received Nobiletin.

“The Nobiletin-treated mice were basically protected from obesity,” said Murray Huff, director of the Vascular Biology Research Group at Robarts and vascular biology scientist at the Western’s Schulich School of Medicine & Dentistry.

“In longer-term studies, Nobiletin also protected these animals from atherosclerosis, the buildup of plaque in arteries, which can lead to a heart attack or stroke. This study really paves the way for future studies to see if this is a suitable treatment for metabolic syndrome and related conditions in people,” he said.

Flavonoids in fruit and red wine have long been believed to have beneficial health effects but the study of specific flavonoids is in its infancy, Huff said.

Nobiletin was previously shown to be promising when applied to cultured cells but the London study was the first to show wide-scale benefits in an animal.

Further research in London has already begun: Huff wants to see if Nobiletin not only prevents disease in mice but reverses it where it’s present. He’s hopeful he’ll have an answer within a year, and if the answer is yes, the next step would be to test the safety of various doses on people — what’s called a phase 1 clinical trial.

Huff suspects there’s not nearly enough Nobiletin in tangerines alone to have the dramatic effect shown in mice — supplements would be needed.

As for eating tangerines themselves, he believes there is a more modest benefit.

Just don’t throw out the peel, or more exactly, the bitter, white pith beneath — that’s where the highest concentration of flavonoids is found.

Huff is no stranger to the benefits of fruit. Two years ago, he discovered a flavonoid in grapefruit called Naringenin offered similar protection against obesity and other signs of metabolic syndrome. But in the battle of fruit, at least with theses specific flavonoids, the tangerine is mightier.

“What’s really interesting to us is that Nobiletin is 10 times more potent in its protective effects compared to Naringenin, and this time, we’ve also shown that Nobiletin has the ability to protect against atherosclerosis,“ Huff said.

E-mail jonathan.sher@sunmedia.ca, or follow JSheratLFPress on Twitter.