Cutting Calories Can Prolong LifeBy Ed Edelson
People who drastically limit their calorie intake can reduce the risk of diabetes and heart disease and stay young longer, real-life research finds.
The study of obviously dedicated members of an organization called the Caloric Restriction Optimal Nutrition Society found they scored significantly better on such major risk factors as cholesterol, blood pressure and insulin levels. A group led by Dr. John O. Holloszy, a professor of medicine at the Washington University School of Medicine, report the finding in this week's issue of the Proceedings of the National Academy of Sciences.
"For the first time we've shown that calorie restriction is feasible and has a tremendous effect on the risk for atherosclerosis [hardening of the arteries] and diabetes," Holloszy said.
The readings of such factors as blood pressure and cholesterol for these middle-aged Americans were typical of much younger people, he said.
The 18 organization members had been taking in about 1,100 and 1,950 calories a day for about six years, with bigger people logically eating more. They were compared to a matched group of 18 people whose daily intake was between 1,975 and 3,550 calories a day, more typical of Americans.
The calorie-restricted group had blood levels of "bad" LDL cholesterol in the lowest 10 percent of people in their age group. The readings for "good" HDL cholesterol, which carries fats out of the arteries, were in the highest 15 percent of their age group. And their levels of triglycerides, fats that contribute to atherosclerosis, were lower than in 95 percent of Americans half their age.
Those readings, and the ones for other factors such as body mass index and body fat, indicate that the low-calorie consumers "are aging less rapidly than normal," Holloszy said.
The study also deals a blow to the current craze over low-carbohydrate diets. The calorie-restricted group got 46 percent of their calories in the form of carbohydrates, with 26 percent from protein and 28 percent from fat. The comparison group got 50 percent of their calories from carbohydrates, 18 percent from protein and 32 percent from fat.
But the low-calorie people got mostly complex carbohydrates, from such foods as fruits and vegetables. The normal eaters were heavy on the simple carbohydrates found in sugary foods.
This is not a diet for the masses, Holloszy acknowledged. The society from which the participants were recruited has about 150 members, and possibly half of them have the discipline to follow the low-calorie diet, he said. Nevertheless, he said, there is a message for the average American eater.
"We are having an epidemic of obesity," Holloszy said. "Just reducing food intake enough to bring the body mass index into the normal range, losing 20 pounds or so, would produce the same kind of changes in the risk factors that would markedly reduce the risk of developing cardiovascular disease and stroke."
Another new study says people should pay more attention to the amount of trans fatty acids they consume. Trans fatty acids, found in margarine, snack foods and the like, are produced by adding hydrogen to ordinary fatty acids.
A diet heavy in trans fatty acids caused development of the early stages of cardiovascular disease in pigs, whose hearts closely resemble those of humans, University of Missouri researchers reported. They presented their finding on April 19 at the Experimental Biology 2004 meeting in Washington, D.C.
"This is the first time we have studied the effects of trans fatty acids in an animal model," said Dr. James R. Turk, an associate professor of pathology at Missouri and a member of the research team. "What we see is quick development of more severe cardiovascular disease."
The lesson for humans, Turk said, is "to avoid trans fatty acids if possible to reduce the amount of cardiovascular disease."
The U.S. Food and Drug Administration last year ordered manufacturers to start listing trans fatty acid content on food labels, but the regulation will not take effect until 2006.
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