Soluble phenolics help prevent onset of Type 2 diabetes

By DAN WHEAT

Capital Press

Apples, with their skin, are potentially the most effective natural combatant of the early stages of Type 2 diabetes, according to a study being completed by a University of Massachusetts professor.

That's because apple skin "is loaded" with so much protective antioxidants or natural compounds called soluble phenolics, said Kalidas Shetty, professor of food science at the University of Massachusetts in Amherst.

In a two-year, $93,000 study for the Washington Tree Fruit Research Commission, Shetty evaluated 10 apple varieties for their potential management of Type 2 diabetes. He concluded that Honeycrisp and Red Delicious are 10 to 15 percent higher in soluble phenolics than Gala, Fuji, Golden Delicious, Ginger Gold, Jonagold, Braeburn, Empire and McIntosh.

But it's not so much the variety as eating more apples that has exciting potential to help prevent Type 2 diabetes or chronic disease in general, Shetty said.

Without animal or clinical studies, he said, he cannot compare the benefits of apples to drugs in fighting Type 2 diabetes. But, he said, apples could complement or supplement drug therapy in early stages when diet and exercise also can be effective.

One 200-gram apple contains an average of 40 to 50 milligrams of soluble phenolics or antioxidants, which is more than the average daily per capita intake in the United States, he said.

The soluble phenolics in apples potentially inhibit the higher load of soluble sugars and starch in refined processed foods that have lost their soluble phenolics during processing, he said.

People in Okinawa, Japan, eating natural foods, average 600 to 800 milligrams of soluble phenolics per day and average longer life spans than anyone on Earth, Shetty said.

Adult-onset Type 2 diabetes and other diseases are on the rise in the United States, China, India and other developed or developing nations as people become more sedentary and eat more processed than natural foods, Shetty said.

People can increase their soluble phenolics by eating more fruits, vegetables and whole grains, he said. Apples appear best because of the thickness and color of their skin, he said. Such benefit cannot be gained from apple juice or other common fruits such as bananas and oranges without skin, he said.

A pear can provide 60 to 70 milligrams of soluble phenolics but apparently of a type better suited to promoting good bacteria in the stomach and intestines and inhibiting bad, ulcer-causing bacteria, Shetty said. Apple antioxidants appear better suited in fighting Type 2 diabetes, he said.

Shetty also found that soluble phenolics in apples are maintained and even enhanced when apples are in cold or controlled-atmosphere storage where 1-MCP, a ripening inhibitor is used.

"The next question is: Can we find optimum levels that translates into better human health?" he said. "It opens a whole new door in research.

"We think phenolics produced by apples for their own needs likely are the same ones that will work best in fighting chronic disease in humans and answer why we should eat five to seven servings of fruits and vegetables per day."

A specific soluble phenolic in apple skin called quercetin is believed to potentially improve athletic endurance by fighting fatigue, he said.

More studies are needed to determine if soluble phenolics can be naturally enhanced through breeding or natural treatments at any stage of fruit development, he said.

Shetty has a $40,000 USDA grant to advance community food systems to get more fruits and vegetables into impoverished areas where consumption is low and chronic diseases are high. He has a $2.5 million proposal to expand community food systems pending before the National Institute for Health and is planning proposals for more studies on apples and phenolics.