It
could help you burn fat, study suggests
Oregon State University, Science
Daily
Drinking red grape juice or wine -- in moderation -- could
improve the health of overweight people by helping them burn fat better,
according to a new study coauthored by an Oregon State University researcher.
The findings suggest that consuming dark-colored grapes, whether
eating them or drinking juice or wine, might help people better manage obesity
and related metabolic disorders such as fatty liver.
One of the chemicals, ellagic acid, proved particularly potent:
It dramatically slowed the growth of existing fat cells and formation of new
ones, and it boosted metabolism of fatty acids in liver cells.
These plant chemicals are not a weight-loss miracle, cautions
Shay. "We didn't find, and we didn't expect to, that these compounds would
improve body weight," he said. But by boosting the burning of fat,
especially in the liver, they may improve liver function in overweight people.
"If we could develop a dietary strategy for reducing the
harmful accumulation of fat in the liver, using common foods like grapes,"
Shay said, "that would be good news."
The study, which Shay conducted with colleagues at the
University of Florida and University of Nebraska, complements work with mice he
leads at his OSU laboratory. In one 2013 trial, he and his graduate students
supplemented the diets of overweight mice with extracts from Pinot noir grapes
harvested from Corvallis-area vineyards.
Some of the mice were fed a normal diet of "mouse
chow," as Shay calls it, containing 10 percent fat. The rest were fed a
diet of 60 percent fat -- the sort of unhealthy diet that would pile excess
pounds on a human frame.
"Our mice like that high-fat diet," said Shay,
"and they overconsume it. So they're a good model for the sedentary person
who eats too much snack food and doesn't get enough exercise."
The grape extracts, scaled down to a mouse's nutritional needs,
were about the equivalent of one and a half cups of grapes a day for a person.
"The portions are reasonable," said Shay, "which makes our
results more applicable to the human diet."
Over a 10-week trial, the high-fat-fed mice developed fatty
liver and diabetic symptoms -- "the same metabolic consequences we see in
many overweight, sedentary people," Shay said.
But the chubby mice that got the extracts accumulated less fat
in their livers, and they had lower blood sugar, than those that consumed the
high-fat diet alone. Ellagic acid proved to be a powerhouse in this experiment,
too, lowering the high-fat-fed mice's blood sugar to nearly the levels of the
lean, normally fed mice.
When Shay and his colleagues analyzed the tissues of the fat
mice that ate the supplements, they noted higher activity levels of PPAR-alpha
and PPAR-gamma, two proteins that work within cells to metabolize fat and
sugar.
Shay hypothesizes that the ellagic acid and other chemicals bind
to these PPAR-alpha and PPAR-gamma nuclear hormone receptors, causing them to
switch on the genes that trigger the metabolism of dietary fat and glucose.
Commonly prescribed drugs for lowering blood sugar and triglycerides act in
this way, Shay said.
The goal of his work, he added, is not to replace needed
medications but to guide people in choosing common, widely available foods that
have particular health benefits, including boosting metabolic function.
"We are trying to validate the specific contributions of
certain foods for health benefits," he said. "If you're out food
shopping, and if you know a certain kind of fruit is good for a health
condition you have, wouldn't you want to buy that fruit?"
The research was supported by the Institute of Food and
Agricultural Science at the University of Florida and Florida Department of
Agriculture and Consumer Services. The study appears in the January issue of
the Journal of Nutritional Biochemistry.
Shay's research with mice was supported by the Blue Mountain
Horticultural Society, the Erath Family Foundation, and the OSU College of
Agricultural Sciences.
Story Source:
The above story is based on materials provided by Oregon State University. The original article was written by
Gail Wells. Note: Materials may be edited for content and length.
Journal Reference:
Meshail Okla, Inhae Kang, Da Mi Kim, Vishnupriya Gourineni, Neil
Shay, Liwei Gu, Soonkyu Chung. Ellagic acid modulates lipid accumulation
in primary human adipocytes and human hepatoma Huh7 cells via discrete
mechanisms. The Journal of Nutritional Biochemistry, 2015; 26 (1):
82 DOI:10.1016/j.jnutbio.2014.09.010
Cite This Page:
Oregon State University. "Another reason to drink wine: It
could help you burn fat, study suggests." Science Daily,
6 February 2015.
<www.sciencedaily.com/releases/2015/02/150206111702.htm>.