Researchers have found a fat molecule called ceramide that contains saturated fatty acids helps speed up muscle deterioration in adults.
A recent study of obesity comparing older and younger men conducted at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University indicates a build-up of a fat molecule called ceramide might play a leading role in muscle deterioration in older adults. The study was published by the Journal of Applied Physiology, a publication of the American Physiological Society, and conducted by a team of researchers headed by Donato Rivas, Ph.D., the study's first author and a scientist in the Nutrition, Exercise Physiology and Sarcopenia Laboratory at Tufts University.
Although it has long been known that fat tissue replaces muscle tissue as people grow older, the researchers were trying to understand whether some fat molecules are more damaging to muscle than others. The team said that they suspected the increased storage of ceramide seen in the older men and compounded by the presence of saturated fat, had a part in weakening the anabolic signaling that responds to resistance exercises and helps with building new muscle.
To study the effects of ceramide, the study examined 10 men in their mid-seventies and nine men in their early twenties. What they shared was that none of the men were overweight or had chronic health problems and none had exercised in six months. Ceramide levels were measured in a muscle biopsy before the participants performed three sets of ten repetitions of knee extensions and leg presses, followed by more muscle biopsies used to examine how the exercise impacted muscle growth. Dr. Rivas said “There is a known relationship between elevated ceramide levels and unhealthy muscle in obese adults, but to the best of our knowledge, this had not been studied in healthy weight, older adults.”
The analysis showed the accumulation of ceramide molecules containing saturated fatty acids were 156% and 30% higher in the older men, and that the accumulation of saturated fatty acids was associated with less leg muscle mass in both younger and older men. Although the takeaway was that the deterioration of muscle and loss of muscle strength begins around age 50 and is a major factor in the decrease in mobility most people exhibit as they age. The good news was that the research also suggests that older adults can effectively maintain and build new muscle with even limited amounts of exercise, and the amount of fat the body builds and stores can be reduced with physical activity too.
