An active compound found in dark-colored grapes and a variety of other fruits and vegetables could help the body burn fat better and decrease the production of fatty acids in the liver, according to new research. But before you pick up that bottle of red wine, the results don’t mean that sipping Shiraz is an effective weight loss tool. However, they could suggest that consuming foods containing high levels of this compound may help people manage obesity and related metabolic disorders, such as fatty liver.
Muscadine grapes, a dark variety native to southeastern U.S., are known to be rich in a variety of nutrients and health-promoting compounds such as polyphenols, which have potent antioxidant and anti-inflammatory properties. Interestingly, previous research by scientists at Oregon State University found that consuming muscadine grape extracts reduced lipid (fat) accumulation in mice fed a high fat diet. At this stage, it was unclear which active compound was exerting these effects, but the researchers had their suspicions that it may have been the work of one particular polyphenol called ellagic acid.
Ellagic acid, a natural antioxidant found in berries, pomegranates and various other plant foods, has received a fair amount of attention as an agent that might help prevent various diseases because of its antioxidant and anti-proliferative properties in cell culture. To find out whether this compound, or something else in muscadine grapes, could also have this apparent lipid-lowering property, scientists scrutinized its effects on cells in a dish.
For the investigation, which has been published in The Journal of Nutritional Biochemistry, researchers exposed both human liver and fat cells to extracts of four natural active compounds found in these grapes. They found that, among the chemicals, ellagic acid seemed to exert a variety of positive effects. Not only did it slow the growth of fat cells and reduce new fat cell formation, but it also reduced the synthesis of fatty acids in adipose tissue, or fat. Furthermore, it also increased the oxidation of fatty acids in the liver cells, meaning it boosted their metabolism.
Although this could suggest that foods containing high levels of ellagic acid may help boost the burning of fat, especially in the liver, which could help improve liver function in obese people, the results don’t mean that this compound is some wonder weight loss tool. “We didn’t find, and we didn’t expect to, that these compounds would improve body weight,” lead researchers Neil Shay said in a news release. “If we could develop a dietary strategy for reducing harmful accumulation of fat in the liver, using common foods like grapes, that would be good news.”
This research also backs up Shay’s previous work in mice which involved supplementing the diets of overweight animals with grape extracts, roughly the equivalent of one and a half cups a day for a human. Half the mice were fed a high-fat diet, whereas the rest were fed a normal diet. Although all the mice on the high-fat diet developed fatty liver and diabetic symptoms, those supplemented with grape extracts accumulated less fat in their livers and had lower blood sugar. Interestingly, these mice also had increased levels of two proteins that are known to metabolize fat and sugar. Of course, this doesn’t necessarily mean the same thing will happen in humans, so further research is warranted.
