Calorie Restriction Lowers Heart Risk
Study Is First in Humans to Show Protection Against Diseases of Aging
April 19, 2004 -- Severely restricting calories has been shown to slow aging and prolong life in mice and rats. Now early research hints that the same just might be true in humans.
In the small study comparing people who practice calorie restriction as a lifestyle with those who ate a more typical Western diet, the calorie-restricted group had dramatically reduced risks of heart disease and diabetes. Researchers reported that their risk factors were so low they were comparable to those of people who were much younger.
"It is clear that calorie restriction has a powerful protective effect against diseases associated with aging," researcher John O. Holloszy, MD, says. "We don't yet know if these people will live longer, but we known that their risk for these diseases is very low."
Study Findings
The study included 18 people who belong to an organization called the Calorie Restriction Optimal Nutrition Society. The group advocates consuming between 10% and 25% fewer calories than is considered normal while being careful to maintain proper nutrition. Men in the group typically eat fewer than 2,000 calories a day and women eat fewer than 1,500.
The findings are published in the April 27 issue of the Proceedings of the National Academy of Sciences.
Eighteen study participants -- including three women -- on calorie restriction had been following the diet for as little as three years and as long as 15, and their daily intake of calories ranged from about 1,100 to 1,950, depending on height, weight, and gender. They were compared with 18 age- and sex-matched people who ate a typical American diet, consuming between 1,975 and 3,550 calories per day.
To examine heart disease risk, the leading cause of death in the U.S., researchers examined heart disease risk factors such as blood pressure and cholesterol. They also measured blood sugar and insulin levels in the blood to evaluate diabetes risk, one of the most significant heart disease risk factors.
The average blood pressure in the normal diet group was 130/80, which is considered above normal. Last year, researchers linked blood pressure over 120/80, called prehypertension, to an increase in heart disease and stroke. Doctors recommend a healthy diet and exercise to treat prehypertension. A blood pressure of 140/90 is officially considered high.