Keeping In Good Shape In Old Age Is Harder For Women Than Men
Women over the age of 65 years have a more difficult time preserving muscle than their male counterparts, which probable impacts their ability to stay as strong and fit, according to new research published on March 26, 2008 in the open-access journal PLoS ONE.
Muscle maintenance is very important in reducing the risk of falls in the elderly, one of the major causes of premature death. After the age of 50, people lose up to 0.4% of their muscle mass every year. This makes them less mobile, more at risk for fracture, and more at risk for potentially life threatening falls.
Of elderly people who suffer a serious fall, one half die within to years. But, it is thought that the number of falls can be curtailed if muscle mass is maintained. This would keep knees and hips more properly supported and strong.
Until now, no differences had been found between men and women in muscle protein synthesis, the process the body uses to build muscle. However, recently, it has been found that the female body's response to food and exercise declines in the mid- to late-60s. Women are at a higher risk for muscle loss because they already tend to have less muscle and more fat than men in early and middle age, so when they reach their 50s and 60s, they are already closer to becoming frail.
Now, scientists have shown for the first time that it is actually more difficult for women to replace naturally lost muscle as they get older, and this difficulty is linked to a key difference in the way men's and women's bodies react to food.
Experts at the Washington University School of Medicine in St Louis, Missouri, USA, and at The University of Nottingham, UK, funded by the US National Institutes of Health, studied 29 men and women aged 65-80 years old who were in good health. They examined the ability to respond to food meant to build muscle mass. It was found that post-menopausal women were less able to respond to this food than men, who were able to store protein in the muscle.
The scientists attribute this change to hormonal adjustments that occur with menopause. Specifically, the suspicion falls on estrogen, which is already known to be necessary in both women and men to help maintain bone mass. According to the researchers, these findings corroborate other preliminary results indicating that women are less able to repsond to build muscle after resistance exercise, such as lifting weights in the gym. Younger men and women, who have not reached menopause, do not seem to show any discrepancy in muscle mass potential.
Regarding this finding, Michael Rennie, Professor of Clinical Physiology at The University of Nottingham, said: "Nobody has ever discovered any mechanistic differences between men and women in muscle loss before. This is a significant finding for the maintenance of better health in old age and reducing demands on the National Health Service."
There is advice for older women to help combat this degeneration. These new results underscore the importance of a diet sufficient in protein, including foods such as eggs, fish, chicken, and lean red meat, as well as resistance exercise.
"Rather than eating more, older people should focus on eating a higher proportion of protein in their everyday diet. In conjunction with resistance exercise, this should help to reduce the loss of muscle mass over time. There is also a case for the beneficial hormonal effect of limited HRT, although this has to be balanced against the other risks associated with such treatment," continues Rennie.
