Staying in Shape is Difficult for Older Women

A new study urges older women to eat more protein to help replace muscle lost during the aging process.

The study was conducted by researchers at the University of Nottingham in the UK and Washington University School of Medicine in the US.  It found that differences in the way male and females bodies metabolize food makes women use protein less effectively to maintain muscle mass. The researchers suggest that women over 65 should eat plenty of high-protein foods such as eggs and meat, along with performing resistance exercises, to minimize age-related muscle loss.

In conducting the study, the Nottingham and Washington team examined 29 men and women aged 65 to 80, and found that after performing resistance exercise like weight lifting, women did not build up muscle in the same way their male counterparts did. It seemed the male body was able to store protein in the muscle and use this to make them stronger.

The researchers speculated that the inability of the female body to perform this function as effectively as the men is linked to declining estrogen levels during menopause. The hormone is known to help maintain bone mass, and the researchers believe it may perform a similar role in the preservation of muscle.

Previous studies found little difference in the way younger men and women build up muscle in the body, suggesting the changes seen in the new study do not kick in until menopause.

"Nobody has ever discovered any mechanistic differences between men and women in muscle loss before," Michael Rennie, professor of clinical physiology at the University of Nottingham, told BBC News.

"This is a significant finding for the maintenance of better health in old age and reducing demands on the National Health Service."

People typically lose up to 0.4% of muscle mass every year after age 50, which can cause them to be less mobile and more prone to falls.   Indeed, half of all elderly people who suffer a serious fall will die within two years.

Women are thought to be particularly at risk, as even in early middle-age they tend to have more fat and less muscle than men of equal age.

"We know that women tend to have less muscle bulk than men as they enter old age so the advice to eat more protein is very sensible indeed," Jackie Lowdon, a British Dietetic Association spokesman, told BBC News.

"Many elderly people subsist on toast and biscuits – food that is easy to make – and there needs to be a much greater focus than there is at present on improving the diets of those who are already vulnerable."

The study was published in the journal Public Library of Science One. The full report can  be viewed here.