Milk top workout drink

Australian scientists have identified a protein in milk which has been shown to encourage both the growth of extra muscle, and the desire to exercise.

Mice given a condensed dose of the protein were shown to change their muscle to fat ratio, says Professor Ben Cocks.

They also wanted to exercise more, and even mice not put through a fitness regime put on some extra muscle bulk.

"When we fed small amounts of the peptide to mice we found it actually changed their muscle ratio a fair bit," says Prof Cocks, Research Director of Biosciences at Victoria's Department of Primary Industries.

"If it could do that in people it would go a long way to supporting exercise, and avoiding metabolic syndrome."

Metabolic syndrome is the combination of high blood pressure, high blood sugar levels and obesity which increases the risk of developing cardiovascular disease and diabetes, conditions suffered by 30 percent of Australians.

Prof Cocks says cows milk had long been known to be beneficial for people seeking to lose weight while retaining their muscle mass.

"People have hypothesised there was something in bovine milk that helped support muscle to fat ratios, so (this protein) could explain that," he says.

People hoping to derive the same benefits seen in the mice from drinking cows milk will have to wait.

The protein is of extremely low dosage in ordinary cows milk - full fat or fat free - but it is of higher concentration in human milk.

Research into the protein, and how it works on muscle, will continue for about another four years but then an "enriched" version of milk could be released.

Or, Prof Cocks says, it could be made into tablets and sold as an exercise supplement.

"It's more likely to be a supplement than a super-charged milk," he says.

The research was unveiled today at the major BIO2009 conference in Atlanta, USA, and the protein has been named RIPTAC (Regeneration Inducing Peptide for Tissues and Cells).

The work was supported by the Victorian government and MG Nutritionals, a division of dairy farmers collaborative Murray Goulburn Cooperative.