GAINESVILLE, Fla. Chemical concoctions can smooth over wrinkles and hide those pesky grays, but what about the signs of aging that aren't so easy to fix, such as losing muscle mass? Cutting calories early could help, say University of Florida researchers who studied the phenomenon in rats.
A restricted-calorie diet, when started in early adulthood, seems to stymie a mitochondrial mishap that may contribute to muscle loss in aging adults, the researchers reported recently in the journal PLoS One.
In rats, the scientists found pockets of excess iron in muscle cell mitochondria, the tiny power plants found in every cell. The excess iron affects the chemistry inside the mitochondria, sparking the formation of harmful free radicals that can lead a mitochondrion straight to the emergency exit, said Christiaan Leeuwenburgh, Ph.D., a UF professor of aging in the UF College of Medicine and the Institute on Aging. Leeuwenburgh was the senior author of the study and of a related report published online this month in Aging Cell that details the damage done by excess iron in mitochondria.
"We become less efficient at an old age and we need to understand why this is," Leeuwenburgh said. "One thing, maybe, is the accumulation of redox-active metals in cells. If the mitochondria become unhappy or are ready to kick the bucket, they have proteins in the inner and outer membranes that they can open up and commit suicide. They're tricky beasts."
The suicidal mitochondria can damage the rest of the muscle cell, leading to cell death and perhaps to muscle wasting, a big problem for adults as they reach their mid-70s, Leeuwenburgh added.
"Muscle is critical for your overall well-being," Leeuwenburgh said. "As you walk, muscle functions partly as a pump to keep your blood going. Muscle is an incredible source of reserves."
The researchers found increasing amounts of iron in the muscle cells of aging rats fed a ty
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University of Florida