A jug of jam and thou

For many generations the people of coastal North Carolina have cultivated the muscadine grape to make wine, pies, jellies and jam. The “tar heels” called these grapes scuppernongs, and if they suspected that the foods they made from these grapes had healthy benefits, they certainly had no idea just how healthy they were.

Two years ago, scientists from the United States Department of Agriculture (USDA) reported a study concluding that muscadine grapes contain high levels of resveratrol, an antioxidant that we know can reduce cardiovascular and cancer risks. Now a follow up study from the USDA brings even more good news about the natural health benefits of these and other dark-skinned grapes.
Chemistry detective work

Resveratrol is a compound commonly found in a variety of fruits such as cranberries and blueberries, but is best known for its abundance in dark grapes, such as the muscadine.

In this new study, reported in the June issue of the Journal of Agricultural and Food Chemistry, researchers identified another compound in grapes called pterostilbene as a possible cancer-preventive agent.

The lead investigator for the study, Agnes M. Rimando, Ph.D., had previously tested pterostilbene and found it to be toxic to a human breast cancer cell line. Knowing also that the chemical structure of pterostilbene is similar to resveratrol, Dr. Rimando set out to determine if pterostilbene might therefore have the same sort of anticancer and antioxidant qualities as resveratrol.

In a series of laboratory tests, the USDA team examined cells extracted from mouse mammary glands. Not only did they find that pterostilbene was able to prevent a type of cell damage normally associated with cancer-causing agents, but they also concluded that pterostilbene may be just as potent as resveratrol in its ability to fight and prevent cancer.
The multi-tasking compound

Pterostilbene also has another very important health benefit: it has been shown to lower blood glucose levels. Previous tests on animals have concluded that pterostilbene may be a highly effective antidiabetic agent. In fact, in one study where it was compared to metformin (the drug most often prescribed for type II diabetes), pterostilbene lowered plasma glucose levels in rats with high blood sugar by 42 percent – statistically equal to the performance of metformin in the same study.

Pterostilbene also has antifungal qualities, as does resveratrol, although pterostilbene has been shown to be anywhere from 60 to 100 times more effective than resveratrol as a fungicide.
Put some jam on that

Dr. Rimando hopes that the USDA research leads to the creation of better ways to fight cancer and diabetes. But much more research will be needed, especially with animals and humans, to better understand and then harness the active biological properties of pterostilbene. In the meantime, she is currently investigating other fruits, in search of additional sources of pterostilbene.

So, if you’re on your way out to the produce stand, you can start enjoying the antioxidant health benefits of pterostilbene today by picking up some muscadine grapes, or other dark-skinned grapes, or juice and jelly products made from these grapes. (Green grapes probably contain some of the compound – but far less than the darker grapes.) And if you were thinking of also picking up a bottle of scuppernong wine – well, don’t let me stop you – but you should know that pterostilbene apparently does not survive the wine-making process. But we can keep that just between us. Cheers! And as always

To Your Good Health,

Jenny Thompson
Health Sciences Institute

Sources:

“Compound identified in grapes may fight cancer and diabetes” American Chemical Society