Egg yolks may be the answer to warding off obesity

December 31, 2013

By AYAKO SUZUKI/ Staff Writer

GIFU--Researchers here say they may have found a key to stopping obesity.

They did this by injecting chickens with an enzyme so they lay eggs that contain an antibody which inhibits fat absorption.

Early results with mice offer promising results, they said.

The work is being done by Satoshi Nagaoka, professor of food functions at Gifu University, and EW Nutrition Japan, also based in Gifu.

Trials with mice were announced early in December in the online version of the British magazine Nutrition & Metabolism.

People and animals dissolve fat with an enzyme called lipase, and absorb it from their intestines. Inhibiting the functions of lipase stops people from absorbing too much fat and, as a result, becoming obese.

In some countries, medicines to inhibit lipase’s functions are already available. However, side effects such as hepatitis have been reported.

Nagaoka’s team produced a protein (antibody) that can inhibit the functions of lipase by uniting only with the enzyme. The team achieved success using hens.

Nagaoka did this by injecting porcine lipase into hens to get them to produce an antibody against lipase in the egg yolks.

Nagaoka purified the yolks. He then created a feed that contained the purified yolks and one that did not. They were given to two batches of mice--eight for each experiment--for 35 days.

The body fat percentage of the group that ate the special feed was 1.6 percent lower on average compared with the mice raised on the ordinary feed.

His team also tested the effectiveness of the yolks in inhibiting the dissolution of fat. It turned out to be 15 times more effective than catechin contained in green tea and twice that of medicines designed to inhibit lipase’s functions.

EW Nutrition has focused much of its research on getting hens to produce special antibodies. So far, it has succeeded in producing antibodies against rotavirus, the most common cause of severe diarrhea among infants, and periodontal pathogens. The company has sold food that contains those antibodies.

“The antibody is different from other food ingredients in that it impinges on fat in a unique manner,” Nagaoka said.

EW Nutrition plans to conduct human trials using the antibody so it can commercialize it as a health food.

By AYAKO SUZUKI/ Staff Writer
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