Love red wine? Study finds ingredient keeps us young
A SUBSTANCE found in red wine may protect the body against age-related diseases by stimulating an ancient evolutionary defence mechanism that guards human cells against genetic damage, scientists said.
Resveratrol, an organic compound found in grapes, nuts and a variety of other edible plants, has already been linked with extending the healthy life of laboratory animals as well as decreasing the incidence of heart disease and other illnesses in humans.
Because red wine is particularly rich in resveratrol, some researchers have suggested that it could explain the "French paradox" of a relatively high-fat diet but relatively low incidence of coronary heart disease within the wine-drinking population of France.
Nevertheless, scientists have disputed whether the supposed effects of resveratrol on human health are real and, if so, how it could be so beneficial. However, researchers have now come up with a possible answer.
The study found that resveratrol mimics another molecule found naturally in the body that is involved in activating an ancient chemical pathway to limit stress and damage to the DNA of cells - which would otherwise result in ageing and disease.
"This stress response represents a layer of biology that has been largely overlooked, and resveratrol turns out to activate it at much lower concentrations than those used in prior studies," said Professor Paul Schimmel of the Scripps Research Institute in La Jolla, California, who led the study published in the journal Nature.
The researchers found that resveratrol mimics a naturally occurring amino acid called tyrosine, which normally binds to one of a family of enzymes that are thought to have evolved many hundreds of millions of years ago when life existed as simple microbes.
One of these enzymes, known as TyrRS, becomes activated when resveratrol binds to it. This causes the enzyme to move into the cell nucleus where it helps to protect the DNA of the chromosomes against genetic damage, the scientists suggested.
The study found that when the TyrRS enzyme enters the cell nucleus it activates a host of protective genes including an anti-cancer gene called p53, which suppresses tumours, and the so-called "longevity" genes implicated in extending lifespans and combating age-related illnesses.
Relatively small levels of resveratrol caused the response. These concentrations were about a thousand times lower than the doses previous studies suggested would produce an effect, said Matthew Sajish, co-author of the Scripps study.
"With these findings we have a new, fundamental mechanism for the known beneficial effects of resveratrol," Dr Sajish said.
"Based on these results, it is conceivable that moderate consumption of a couple of glasses of red wine would give a person enough resveratrol to evoke a protective effect via this pathway," he said.
The researchers suggest that the reason why resveratrol, a plant compound, can cause such a pronounced effect on animals is that it does much the same thing in plants. They suggested the TyrRS enzyme is part of an ancient defence system that predates the divergence of the animal and plant kingdoms.
"We believe that TyrRS has evolved to act as a top-level switch or activator of a fundamental cell-protecting mechanism that works in virtually all forms of life," Dr Sajish said.
Resveratrol: The "elixir" of youth
Various studies have indicated that resveratrol may be beneficial to health by possessing anti-oxidative, anti-carcinogenic or anti-tumour properties. The full scientific name is trans-3,5,4-trihydroxystilbene and it is found in the vines, roots, seeds and stalks of vine plants, but it becomes particularly concentrated in the skins of grapes, possibly as a defence against fungal attack. Red wine typically contains more resveratrol than white wine because of the habit of leaving grape skins for longer during fermentation. Other foods that contain resveratrol include peanuts and soy.