BMI went down. But sophisticated tests such as magnetic resonance imaging and biochemical studies also showed that their bodies were better able to manage blood sugar levels and that there were beneficial effects on heart muscle cells.
"The news here is that heart muscle in obese diabetic individuals can be mobilized by eating less," said Dr. Heinrich Taegtmeyer, professor of medicine in cardiology at the University of Texas Health Sciences Center in Houston and co-author of an accompanying editorial comment.
To be sure, the mechanism by which dieting helps heart cells "is only vaguely understood," Taegtmeyer said. "It gets very biochemical and very molecular." A simple explanation is that caloric restriction activates an enzyme that prevents fat from being deposited in heart cells, he said.
Whatever the mechanism, the new research provides "one more reason not to be fat," Peterson said. Some obese people have taken comfort from studies indicating that they're more likely to survive a heart attack than thinner people, he noted. The new study indicates that the reason for that better survival is the heart attack in fat people occurs earlier in life, when people are otherwise sturdier, he said.
"If you had your choice, you would choose not to have a heart attack in the first place," Peterson said.
Both Peterson and Taegtmeyer cited animal studies showing that strict caloric restriction lengthens life.
"It has been shown in virtually every organism, from yeast to flies to worms to mammals, that caloric restriction heightens life expectancy," Taegtmeyer said. "The heart functions better with caloric restriction."
Learn more about obesity and its ill effects from the U.S. National Library of Medicine.
SOURCES: Eric D. Peterson, M.D., M.P.
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