| Cutting Calories May Keep Heart Young
NEW YORK (Reuters
Health) - Cutting calories may do more
than help people shed excess weight, research suggests. According
to a new report, a low-calorie diet may also slow age-related
changes in the heart's genes that can lead to chronic disease.
In the study, "middle-aged" 14-month-old
mice were fed either a normal diet or one restricted in calories.
When the mice reached 30 months of age, or the equivalent of 90
years of a human life span, the researchers analyzed their heart
The hearts of mice on the low-calorie
diets showed nearly 20% fewer age-related genetic changes and
also appeared to have less DNA damage than those of mice on regular
diets. Restricting calories also inhibited potentially disease-causing
changes in the immune system, and suppressed apoptosis, or programmed
While apoptosis is beneficial in tissues
that undergo rapid DNA replication, such as skin, it can be damaging
in other tissues, Dr. Tomas A. Prolla, the study's lead author,
explained in an interview with Reuters Health.
"In the heart, which largely doesn't
have dividing cells, the process of apoptosis acts to kill cells
that can't be replaced. So in the long term, it is not beneficial,"
said Prolla, a researcher with the University of Wisconsin in
The findings, which appear in this
week's online early edition of the Proceedings of the National
Academy of Sciences, add to a growing body of research demonstrating
the benefit of cutting back on calories. Previous studies have
shown that calorie restriction can slow the aging of the muscles,
brain and heart.
Prolla said a 30% reduction in normal
caloric intake could probably do the trick. A person who normally
consumes about 2,000 calories, for instance, could eat 600 fewer
calories a day.
"As a whole, the data show that it
is highly likely that calorie restriction can retard the aging
process," Prolla said. "Even in middle age, calorie restriction
can reduce rates of aging in the heart."
He cautioned that individuals who
want to try cutting back on their food intake make sure they are
getting enough vitamins and minerals to prevent deficiencies,
and recommended including plenty of whole grains, fruits and vegetables.
SOURCE: Proceedings of the National
Academy of Sciences 2002;10.1073.
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