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Study Reveals Red Wine Improves Health of Obese Mice

November 2, 2006 at 7:48 AM EDT
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JIM LEHRER: And finally tonight, the headline-generating story about mice, red wine, and the quest for a longer and healthier life. Jeffrey Brown has our story.

JEFFREY BROWN: Those morning headlines were fun and irresistible. “Yes, red wine holds answer, check dosage.” “Fat, boozey and healthy, another toast to red wine.”

Behind the headlines is an experiment in which mice were put on a high-fat diet, but one group of them was also given high doses of resveratrol, a natural substance found in red wine. Our health correspondent, Susan Dentzer, is here to tell us what happened.

So in short, Susan, the mice who were given this substance were healthier and lived longer.

SUSAN DENTZER, NewsHour Health Correspondent: That’s right.

JEFFREY BROWN: Tell us about it.

SUSAN DENTZER: Exactly right. Resveratrol is a naturally occurring substance that’s found not just in red wine, but also grapes, peanuts, blueberries, even certain kinds of pine trees, although you didn’t see headlines today suggesting that people drink pine pitch to get the benefit.

In essence, it’s been known to be given to various species and extend their lives. It’s been shown to do that in the lowly yeast, in worms, and in flies. The researchers in this study decided to test it in mice. Why? Because mouse genes and human genes overlap by about

90 percent, so if something works in mice, it’s likely it could work in humans.

They divided the mice up into three groups. One group got the standard healthy mouse diet. And the other two groups got the McDonald’s equivalent of a mouse diet, high in fat and high in calories. And one of those high-fat diet groups also got the resveratrol.

What happened was fascinating: In fact, when the mice eventually went on to die, they dissected their livers, and the livers of the mice on the high-fat diet were very fatty. That was not the case with the mice on resveratrol. The mice on the high-fat diet alone were developing the early stages of diabetes, not the case for the other mice.

And in fact, overall, the mice who got the resveratrol seemed to be living about 15 to 20 percent longer, and their risk of dying from the same conditions that eventually would go on to kill the high-fat diet mice was cut by about 30 percent.

Resveratrol's effects on the body

JEFFREY BROWN: So what is the thinking about why or how it would have this impact on the body?

SUSAN DENTZER: It seems to mimic a process known as calorie reduction. We also know from various studies that if you take even human beings and cut what we would consider the normal diet calorie content by about a third, you can extend life. You can do that in humans and in other species.

Why that is the case isn't utterly clear. The hypothesis that many of the researchers in this study have is that it all relates to a gene called sirtuins, and it seems to be that the resveratrol acts on that gene in some way. That gene is associated with enzymes that help to regulate the body's production of insulin in response to diet.

So putting it all together, this gene may have had a role for millions of years in human evolution, helping protect us against the effect of famine by regulating our insulin production. It now looks like it may have a role, through resveratrol kicking it off, in regulating our ability to survive in an era, frankly, of gluttony.

JEFFREY BROWN: Now, as you said, and as we said with those headlines, the focus was on wine, I guess because many of us like to drink red wine. But there's a big but, right? I mean, the dosage involved is impossible.

SUSAN DENTZER: You'd have to drink several hundred glasses a day of red wine to get as much resveratrol as these mice got. Or if you bought it as a supplement over-the-counter, as you can buy resveratrol supplements, you'd have to take several hundred pills a day in order to get the same benefit.

So, really, the headlines aside, nobody is suggesting that you deal with this by drinking a lot of red wine. What is, in fact, going to be done now is much more testing to establish what the effect of this is in very pure doses in humans. And, in fact, that's already under way in some pharmaceutical companies. And, in fact, one of the researchers involved in this study, David Sinclair, has a company, Sirtris, which is testing high doses of resveratrol in patients with diabetes.

Applications for ongoing research

JEFFREY BROWN: So the way to think about this, really, is in terms of ongoing research into health, disease and aging?

SUSAN DENTZER: Absolutely. And the biggest possible near-term implication would be helping to combat the woes of obesity.

In fact, obesity, we know, is correlated with, not just heart disease, but also cancers, as well, and, of course, diabetes.

If we could offset the effect -- and that's really what happened in these mice. The effect of them having a high-fat diet was almost completely offset by the resveratrol. If we could use a drug that was based on resveratrol to have the same effect on obese people, we could go a long way to mitigating the terrible consequences, mortality and otherwise, that appear to be headed our way because of the obesity epidemic.

JEFFREY BROWN: You said a lot more study is required. What are we looking at? I mean, is this over a long, long period? What end result might there be?

SUSAN DENTZER: Well, the simple answer is nobody knows.

These tests are under way now. The same researchers will continue to monitor the effects in mice to see what really happens over a longer time period.

As I say, the tests are already under way in humans. It could be a matter of years, could be sooner. But it's very, very promising, and we shouldn't at all dismiss the results. They are exciting. It's just that it doesn't mean you should lift a glass of red wine and a toast right away to us having found the fountain of youth.

JEFFREY BROWN: Well, in our last minute, though, go back to the wine, because people are always interested in this. There's been a lot of talk, a lot of studies about the benefits of alcohol and wine.

SUSAN DENTZER: And that's the important point. The benefits are not just red wine. The benefits are across-the-board in moderate amounts of alcohol consumption.

If you drink a beer in moderate amounts, it gives you the same benefit. If you drink chardonnay in moderate amounts, it gives you the same benefit, protecting against heart disease. Red wine, again, just to get the resveratrol aspect alone, you'd have to drink gallons and gallons of this. But if you just stick with moderate amounts of alcohol, you will be protected against heart disease to some degree.

JEFFREY BROWN: All right. Susan Dentzer, thanks a lot.

SUSAN DENTZER: Thanks, Jeff.