Leucine

[Guest guest]

Members may be interested in the following:

The secret of 'muscular' old age

http://news.bbc.co.uk/1/hi/health/4502862.stm

<<<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.

Slow down Once adults reach 40, they start to lose between 0.5 and 2%

of their muscle each year. 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 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. " >>>>

-------------

Carruthers

Wakefield, UK