Resveratrol Studies

Auburn, Sept. 16, 2003 --- Just as Ponce de Leon searched for a fountain of youth, scientists have worked for decades to identify chemicals that may prolong human life.

Now, they think they have found one, and it may be as close as the nearest bottle of red wine, though they’re among the first to caution that drinking red wine is no guarantee you will get adequate amounts of this substance.

“We already know that maintaining body weight and doing other things such exercising daily will probably help you live longer, but you won’t live past the normal lifespan of about 110 years,” said Dr. Robert Keith, an Alabama Cooperative Extension System nutritionist and Auburn University professor of nutrition and foods who has been closely following the issue.

But the substance isolated in red wine, known as resveratrol, may offer humans something more: the chance to live beyond the normal human lifespan.

Scientists have discovered that resveratrol could possibly prolong the normal human lifespan by mimicking the effects of a calorie-restricted diet, a regimen that has already been tried with smaller mammals, such as mice and rats, with stunning effects. Laboratory animals placed on this diet, which restricts calories to between two-thirds and three-fourths of what they normally would receive in the course of their lives, though intakes such as vitamins and minerals remain the same, have lived as long as 50 percent beyond their normal lifespan. In human terms, this amounts to about 160 years.

“There have been various theories and guesses as to how this happens,” Keith observed. “One is that it slows down metabolism. Scientists have known that damage from substances known as free radicals is one of the causes of aging. But if you slow down metabolism and take in less oxygen, you produce fewer free radicals and live longer.”

This may be one contributor, Keith said, though scientists also suspect that the stress associated with lack of calories may activate genes that enable animals, possibly including humans, to live longer. It is a process that apparently was hardwired into various species in the course of evolution. The specter of starvation appears to trigger certain genes in the body that produce a chemical effect that increases lifespan so that reproduction is more likely to occur.

“They found the genes being turned on in response to this stress were shared by all of the organisms tested, from yeast all the way to mice and rats,” Keith said. “And through these observations, they have been able to construct a model that shows which genes within these organisms’ bodies are turned on when this restriction occurs.”

Once scientists isolated the cluster of genes affected by caloric restriction, they then began identifying the specific chemicals that activate them.

“What they’re finding is that some of the compounds found in fruits and vegetables we’re already urging people to eat may be associated with this process,” Keith said.

Resveratrol, from a class of chemicals known as polyphenols, is one of the most promising of several chemicals associated with this genetic process. Resveratrol is commonly found in grape skins, though the amounts in red wine tend to be almost 10 times higher than those found in white wine. Resveratrol appears to be especially abundant in red wines produced in cooler regions with heavier disease pressure, such as Burgundy and New York, rather than in drier climates, such as Australia and California, where pressure is not as intense.

Polyphenols and other plant compounds are produced by plants under stress, which may account for why red wines produced in areas of heavy disease pressure possess more abundant amounts of reservatrol than wines produced within less challenging conditions, Keith said.

Scientists have also discovered that flavones, found abundantly in olive oil and other vegetables, also produce the same effect.

Researchers involved in resveratrol studies are hopeful the chemical eventually can be synthesized and sold as a life-expanding drug. Even so, they contend that there is no guarantee the results already observed in lower animals can be produced in humans. Red wine consumption is no guarantee either.

And besides, Keith said, even if scientists come up with a magic bullet in the form of a pill, there is no proof that it alone will prolong life significantly.

“One thing they’ve learned about caloric restriction is that in addition to turning on certain genes that prolong life, it also results in smaller bodies. Animals on these calorie-restricted diets are smaller and possess far less body fat.

“So it may be that having smaller bodies and possessing less fat is just as critical a factor as genetic effects in prolonging life.”

(Source: Dr. Robert Keith, Extension Nutrition and Auburn University Professor of Nutrition and Foods, 334-844-3273.)

Article in MS Word

Article in Text