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Study unlocks secret of longer life
Discovery of how eating less can prolong lifespan could lead to new drugs designed to slow aging
By Rebecca Lindell, Postmedia News - November 19, 2010
American scientists have discovered the key to how eating less can lead to a longer, healthier life -- an enzyme that curbs cell damage.
The discovery, by scientists at the University of Wisconsin-Madison, could lead to new drugs designed to slow aging and to enhance health in the golden years.
Scientists have studied the relationship between caloric intake and life expectancy for decades; this study, published Thursday in the journal Cell, unveils the cause.
"This study is the first direct proof for a mechanism underlying the anti-aging effects we observe under caloric restriction," said Tomas A. Prolla, a UW-Madison professor of genetics and a senior author of the study.
"It's not just about extending life, it's extending the quality of life," said Russ Hepple, an associate professor at the University of Calgary and former member of the Institute on Aging. "You live to be 80 and you might expect to live 70 of those years in good health. Caloric restriction would allow you to live ... to 100 for example, and 95 of those years in good health."
While studying caloric restriction in hearing impaired mice, the team found that sirtuins, a type of enzyme, are key determinants of the aging process. Of particular importance is a sirtuin called Sirt3.
This particular enzyme works on the cell's mitochondria, which produce energy and a form of oxygen known as free radicals.
Free radicals are naturally occurring in the body, but as people age their levels become excessive, Prolla said. The free radicals damage cells and promote aging, but Sirt3 can curb their release under conditions of reduced caloric intake.
"If we can find drugs or nutritional interventions that activate Sirt3, we may be able to slow down the aging process in mammals," Prolla said, adding that it could take years to get these products on pharmacy shelves.
Scientists first started studying how caloric intake impacts longevity in 1934, when researchers at Cornell University discovered that lab rats who were fed less than normal, while still getting the vitamins and minerals they needed, lived longer than rats eating regularly.
Until scientists figure out a drug or supplement, people wanting to lengthen their lifespan have to decrease their caloric intake by the same percentage.
For example, an extra 10 years requires a 10-per-cent reduction in calories.
Hepple said the problem is humans are only able to tolerate about 20-per-cent calorie reduction because their brains don't adapt to hunger as their bodies do.
Gaining a few extra years through a strict diet may not be fun, warns Dr. Yoni Freedhoff, an Ottawa-based doctor who specializes in weight management and obesity.
"Food is a pleasure in life and denying yourself pleasure from food is certainly a very large price to pay when you've got a whole life to live and now the life is going to be longer," he said.
© Copyright (c) The Vancouver Sun
source: http://www.{censored}/health/Study+unlocks+secret+longer+life/3852851/story.html
Discovery of how eating less can prolong lifespan could lead to new drugs designed to slow aging
By Rebecca Lindell, Postmedia News - November 19, 2010
American scientists have discovered the key to how eating less can lead to a longer, healthier life -- an enzyme that curbs cell damage.
The discovery, by scientists at the University of Wisconsin-Madison, could lead to new drugs designed to slow aging and to enhance health in the golden years.
Scientists have studied the relationship between caloric intake and life expectancy for decades; this study, published Thursday in the journal Cell, unveils the cause.
"This study is the first direct proof for a mechanism underlying the anti-aging effects we observe under caloric restriction," said Tomas A. Prolla, a UW-Madison professor of genetics and a senior author of the study.
"It's not just about extending life, it's extending the quality of life," said Russ Hepple, an associate professor at the University of Calgary and former member of the Institute on Aging. "You live to be 80 and you might expect to live 70 of those years in good health. Caloric restriction would allow you to live ... to 100 for example, and 95 of those years in good health."
While studying caloric restriction in hearing impaired mice, the team found that sirtuins, a type of enzyme, are key determinants of the aging process. Of particular importance is a sirtuin called Sirt3.
This particular enzyme works on the cell's mitochondria, which produce energy and a form of oxygen known as free radicals.
Free radicals are naturally occurring in the body, but as people age their levels become excessive, Prolla said. The free radicals damage cells and promote aging, but Sirt3 can curb their release under conditions of reduced caloric intake.
"If we can find drugs or nutritional interventions that activate Sirt3, we may be able to slow down the aging process in mammals," Prolla said, adding that it could take years to get these products on pharmacy shelves.
Scientists first started studying how caloric intake impacts longevity in 1934, when researchers at Cornell University discovered that lab rats who were fed less than normal, while still getting the vitamins and minerals they needed, lived longer than rats eating regularly.
Until scientists figure out a drug or supplement, people wanting to lengthen their lifespan have to decrease their caloric intake by the same percentage.
For example, an extra 10 years requires a 10-per-cent reduction in calories.
Hepple said the problem is humans are only able to tolerate about 20-per-cent calorie reduction because their brains don't adapt to hunger as their bodies do.
Gaining a few extra years through a strict diet may not be fun, warns Dr. Yoni Freedhoff, an Ottawa-based doctor who specializes in weight management and obesity.
"Food is a pleasure in life and denying yourself pleasure from food is certainly a very large price to pay when you've got a whole life to live and now the life is going to be longer," he said.
© Copyright (c) The Vancouver Sun
source: http://www.{censored}/health/Study+unlocks+secret+longer+life/3852851/story.html
