Last week it was reported that strawberries may help treat throat cancer, now a new study shows how blueberries may aid in curbing obesity.
Plant polyphenols have been shown to fight adipogenesis, which is the development of fat cell, and induce lipolysis, which is the breakdown of lipids and fat. The study was done to evaluate whether blueberry polyphenols play a role in adipocyte differentiation, the process in which a relatively unspecialized cell acquires specialized features of an adipocyte, an animal connective tissue cell specialized for the synthesis and storage of fat.
Polyphenols occur in all plant foods and contribute to the beneficial health effects of vegetables and fruit. Their contribution to the antioxidant capacity of the human diet is much larger than that of vitamins. The total intake in a person's diet could amount to 1 gram a day, whereas combined intakes of beta-carotene, vitamin C, and vitamin E from food most often is about 100 mg a day.
Phenolic acids account for about one third of the total intake of polyphenols in our diet, and flavonoids account for the remaining two thirds. Flavonoids are further subdivided into several categories.
Shiwani Moghe, a graduate student at Texas Woman's University said:
"The promise is there for blueberries to help reduce adipose tissue from forming in the body I wanted to see if using blueberry polyphenols could inhibit obesity at a molecular stage. We still need to test this dose in humans, to make sure there are no adverse effects, and to see if the doses are as effective. This is a burgeoning area of research. Determining the best dose for humans will be important."
Phenolic acids are simple molecules such as caffeic acid, vanillin, and courmaric acid. Phenolic acids form a diverse group that includes the widely distributed hydroxybenzoic and hydroxycinnamic acids. Phenolic acid compounds seem to be universally distributed in plants. They have been the subject of a great number of chemical, biological, agricultural, and medical studies. Hydroxycinnamic acid compounds (p-coumaric, caffeic acid, ferulic acid) occur most frequently as simple esters with hydroxy carboxylic acids or glucose, while the hydroxybenzoic acid compounds (p-hydroxybenzoic, gallic acid, ellagic acid) are present mainly in the form of glucosides. Ellagic acid is found in Pomegranate.
Furthermore, phenolic acids may occur in food plants as esters or glycosides conjugated with other natural compounds such as flavonoids, alcohols, hydroxyfatty acids, sterols, and glucosides. Coffee is particularly rich in bound phenolic acids, such as caffeic acid, ferulic acid, and p-coumaric acid. Phenolic acids found in blueberries include gallic acid, p-hydroxybenzoic acid, coffeic acid, p-coumaric acid and vanillic acid.
The study was performed in tissue cultures taken from mice. The polyphenols showed a dose-dependent suppression of adipocyte differentiation. The lipid content in the control group was significantly higher than the content of the tissue given three doses of blueberry polyphenols.
The highest dose of blueberry polyphenols yielded a 73% decrease in lipids; the lowest dose showed a 27% decrease.
Red wine also has anthocyanosides, catechins, proanthocyanidins, stilbenes and other phenolics.
Several studies have shown that a group of polyphenol antioxidant compounds found in grapes, green tea, soybeans and wine may lower the risk of a range of cancers, but exactly how these powerful compounds work has remained unclear.
Sources: Experimental Biology and Dr. Ray Sahelian, M.D
Written by Sy Kraft