Grapes for Weight Loss and Vision

Exciting News Linking Grapes with Piceatannol to Weight Loss and Better Vision
WEST LAFAYETTE, Ind. – A compound found in grapes and other fruits, and similar in structure to resveratrol, is able to block cellular processes that allow fat cells to develop, opening a door to a potential method to control obesity, according to a Purdue University study.

Kee-Hong Kim, an assistant professor of food science, and Jung Yeon Kwon, a graduate student in Kim’s laboratory, reported in this week’s issue of the Journal of Biological Chemistry that the compound piceatannol blocks an immature fat cell’s ability to develop and grow.

While similar in structure to resveratrol ? the compound found in red wine, grapes and peanuts that is thought to combat cancer, heart disease and neurodegenerative diseases ? piceatannol might be an important weapon against obesity. Resveratrol is converted to piceatannol in humans after consumption.

“Piceatannol actually alters the timing of gene expressions, gene functions and insulin action during adipogenesis, the process in which early stage fat cells become mature fat cells,” Kim said. “In the presence of piceatannol, you can see delay or complete inhibition of adipogenesis.”

Over a period of 10 days or more, immature fat cells, called preadipocytes, go through several stages to become mature fat cells, or adipocytes.

“These precursor cells, even though they have not accumulated lipids, have the potential to become fat cells,” Kim said. “We consider that adipogenesis is an important molecular target to delay or prevent fat cell accumulation and, hopefully, body fat mass gain.”

Kim found that piceatannol binds to insulin receptors of immature fat cells in the first stage of adipogenesis, blocking insulin’s ability to control cell cycles and activate genes that carry out further stages of fat cell formation. Piceatannol essentially blocks the pathways necessary for immature fat cells to mature and grow.

Piceatannol is one of several compounds being studied in Kim’s laboratory for its health benefits, and it is also present in different amounts in red grape seeds and skin, blueberries, passion fruit, and other fruits.

Kim would like to confirm his current finding, which is based on a cell culture system, using an animal model of obesity. His future work would also include determining methods for protecting piceatannol from degrading so that concentrations large enough would be available in the bloodstream to stop adipogenesis or body fat gain.

“We need to work on improving the stability and solubility of piceatannol to create a biological effect,” Kim said.

The Purdue Research Foundation funded the work.

Vine Fruit Fights Vision Loss in 2 Ways

A new study shows one fruit may stop you from going blind in old age. The results are in the early stages but they offer hopeful news in the face of a growing problem.

We’ve told you before how age-related macular degeneration (AMD) is becoming a major health issue. And we’ve given you one nutrient that can reduce your risk of blindness by 43 percent.

But now this new research shows that one vine fruit – with antioxidant properties – may also protect your eyes.

The study was led by Dr. Silvia Finnemann. She’s a top scientist at Fordham University in New York. And you can read about her results in Free Radical Biology and Medicine.

She says the fruit “was remarkable” for protecting eyesight. She also says this fruit can protect your vision in old age?even if you haven’t eaten it since you were a kid.

From the Vine to the Eye

The eye-protecting fruit is the grape. While the study was conducted on animals, these early results are still very hopeful. Adding grapes to your diet certainly won’t hurt you. And they may be able to protect your eyes in old age.

For her study, Dr. Finnemann used mice that were prone to developing retinal damage in old age. She compared three different diets on them to see which one offered the most eye protection.

The three diets were a grape-enriched diet, a normal diet, and a diet with lutein added to it. Lutein, as you may know, is a popular nutrient used in vision supplements. It has plenty of research to prove it works. And that’s where Dr. Finnemann had her breakthrough. Lutein worked pretty well…but grapes worked even better.

Prevents Blindness in 2 Ways

So how do grapes help your eyes? Actually, they do it in two ways. First, they decrease the build-up of lipofuscin. Those are “wear-and-tear” pigments linked to AMD.

Second, they prevent oxidative damage to the retinal pigment epithelium cells (RPE). These cells support photoreceptors in the retina that help convert light to sight.

AMD is a result of oxidative damage over time. So it makes sense that grapes can help. That’s why Dr. Finnemann thinks a lifelong, natural antioxidant diet will benefit your vision.

That’s good news for the aging population. AMD is the leading cause of blindness in this group. So it’s smart to take protective measures, like eating grapes, to prevent AMD from developing.

You can get grapes in any grocery store. Most nutritional experts recommend red grapes for their high antioxidant value. You’ll also find red grapes have decent amounts of resveratrol, quercetin, and catechins.

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