Webmail: PlaNet www.pl.net
0800 752638
Planet Communications— delivering socially and environmentally conscious internet and media services since 1992.
PlaNet News & Views
|
|
|
Posted on 1-4-08 Stay Strong Into Old Age
From bbc.co.uk, 1 April 2008 Photo shows man in 30s and 101 year old
Maintaining muscle mass is easier when young. Scientists believe they have
found a way to enable the elderly to maintain muscle.
Muscle is constantly being built and broken down, which works to maintain
a balance in young adults. But as people age, the breakdown process is
more successful than the muscle-building action. However French
researchers, writing in the Journal of Physiology, say adding the amino
acid leucine to old people's diets could help them keep muscle.
Leucine is found in meat, soy beans and legumes, among other foods.
Once adults reach 40, they start to lose between 0.5 and 2% of their
muscle each year. People should maintain their protein intake as they age
said Dr Michael Rennie, University of Nottingham Medical School at Derby.
The team from the Human Nutrition Research Centre of Auvergne, in
Clermont-Ferrand, France looked at the behaviour of proteins in muscle. As
in all mammalian tissues, proteins are created (synthesised) from amino
acids and digested (degraded) by enzymes. Straight after a meal, the rate
of synthesis doubles, prompted by the arrival of a large amount of amino
acids. The rate of the breakdown of protein is highest in-between meals.
The difference between the two rates determines how much protein remains
in the muscle. But, in older animals - and, it is believed, humans - the
amino acid stimulus prompting synthesis is less effective, and the process
slows down.
However, the breakdown of proteins is not, leaving older animals with less
protein than their younger counterparts. The researchers compared protein
breakdown in young (eight-month-old) and old (22-month) rats. They
discovered that the slow down in degradation that normally follows a meal
does not occur in old animals, so there is excessive breakdown. But when
the scientists boosted levels of one amino acid, leucine, the balance of
synthesis and breakdown was restored.
Falls danger
The team, led by Dr Didier Attaix, suggest the protein processing
imbalance which comes with age results from defects in the complex
machinery that breaks down muscle protein, and that leucine
supplementation can fully restore correct function. He said: "Preventing
muscle wasting is a major socio-economic and public health issue, that we
may be able to combat with a leucine-rich diet."
Dr Michael Rennie from the University of Nottingham Medical School at
Derby told the BBC News website more research into the finding was needed.
But he said older people could make changes to their diet now which could
help them maintain muscle. "If they don't, they can fall over more easily;
they can trip down stairs or fall in the bath." Dr Rennie said older
people could act now, even before further research had been carried out.
"Leucine is most abundant in meat, so it makes sense in terms of protein
synthesis to eat meat. "As people get older, they tend to need to eat
less. But people should maintain their protein intake as they age."
|
