June 2006
Cut calories for a longer life
Amid the sea of modern-day excess, a small group of dedicated souls is committed to eating less in hopes of living a longer,
healthier life. Founded in 1994, the U.S.-based Calorie Restriction Society (CRS) has about 500 dues-paying members. U.S.
and Italian scientists recruited CRS members for a study to see whether calorie reduction, which research has shown extends
the life of everything from fish to rats, also works for humans.
Researchers matched CRS members, who had followed a nutrient-rich diet of less than 2,000 calories each day for between 3 and 15 years, with controls, who consumed a typical American diet of up to 3,500 daily calories. The most recent study, published in the Jan. 17, 2006, issue of the Journal of the American College of Cardiology, looked at the heart functions that typically decline with age. Results showed that hearts of the 25 CRS members functioned like those of people up to 15 years younger.
A previous study of CRS members found that compared with controls, the 18 subjects who practiced calorie restriction scored better on every measure of cardiovascular health, including body fat, cholesterol, blood sugar, and blood pressure. Medical records of CRS members reveal that before changing their eating habits, their cholesterol and blood pressure levels were similar to that of the American-diet group.
It's impossible to say whether calorie restriction itself, or some secondary effect such as lower weight or blood pressure, is responsible for the apparently youthful hearts of CRS members. However, calorie restriction appears to be the only factor that has consistently been shown to slow the aging process in lab-animal studies. And it apparently works independent of weight or the amount of exercise.
There is, of course, a point of diminished returns. When their calories are cut by more than half, lab rodents die sooner. And population studies show that people who are either underweight or obese have an increased risk of mortality compared with those whose weight falls in the normal range.
"Cutting your calories in half doesn't mean eating half your hamburger, French fries, and sugary drink," said Luigi Fontana, M.D., Ph.D., assistant professor of medicine at Washington University in St. Louis, one of the study authors. CRS members carefully select foods based on nutritional value. "In fact, you automatically restrict calories when you cut out the junk and instead focus on healthy foods--fruits, vegetables, beans, whole grains, fish, and lean meat," Fontana said.
Researchers matched CRS members, who had followed a nutrient-rich diet of less than 2,000 calories each day for between 3 and 15 years, with controls, who consumed a typical American diet of up to 3,500 daily calories. The most recent study, published in the Jan. 17, 2006, issue of the Journal of the American College of Cardiology, looked at the heart functions that typically decline with age. Results showed that hearts of the 25 CRS members functioned like those of people up to 15 years younger.
A previous study of CRS members found that compared with controls, the 18 subjects who practiced calorie restriction scored better on every measure of cardiovascular health, including body fat, cholesterol, blood sugar, and blood pressure. Medical records of CRS members reveal that before changing their eating habits, their cholesterol and blood pressure levels were similar to that of the American-diet group.
It's impossible to say whether calorie restriction itself, or some secondary effect such as lower weight or blood pressure, is responsible for the apparently youthful hearts of CRS members. However, calorie restriction appears to be the only factor that has consistently been shown to slow the aging process in lab-animal studies. And it apparently works independent of weight or the amount of exercise.
There is, of course, a point of diminished returns. When their calories are cut by more than half, lab rodents die sooner. And population studies show that people who are either underweight or obese have an increased risk of mortality compared with those whose weight falls in the normal range.
"Cutting your calories in half doesn't mean eating half your hamburger, French fries, and sugary drink," said Luigi Fontana, M.D., Ph.D., assistant professor of medicine at Washington University in St. Louis, one of the study authors. CRS members carefully select foods based on nutritional value. "In fact, you automatically restrict calories when you cut out the junk and instead focus on healthy foods--fruits, vegetables, beans, whole grains, fish, and lean meat," Fontana said.
