The more muscle mass people over 65 have the lower their chance of dying. Lean body mass protects as the years pass, write researchers from Umea University in Sweden this month in Age and Ageing.
The Swedish researchers used data on 921 men and women aged between 65 and 89, which they had been collecting since 1991. The researchers determined the men and women's body composition because they were researching osteoporosis. In mid 2009 the researchers found out which men and women were still alive, and then looked to see whether there was a relationship between survival and body composition.
The table below summarises the relationships they found. Among the women the mortality rate was lower the higher their lean body mass, but fat mass also had a protective effect. The gynoid fat in particular seems to have a protective effect. This is the fat that you associate typically with women, such as fat on the hips. People with a lot of gynoid fat have a pear-shaped body.
In the men lean body mass also reduced the mortality rate. When it comes to the amount of fat, it seems that for men there is an optimum amount. Men with very little fat are more likely to die, as are men with a very large amount of fat. Whether that optimal amount of body fat is located in a typically male place – and then we're talking about abdominal fat – or not, makes little difference in men.
If the Swedes have got the right end of the stick, you'd expect strength training to extend life expectancy?
Age Ageing. 2012 Sep;41(5):677-81.