There's often a whiff of snake oil around anti-ageing supplements especially when they feature on the Dr Oz show.

In a 2012 segment Dr Oz declared that the supplement carnosine an amino acid found naturally in muscle can "take your body back ten years", improving wrinkles and lifting energy levels.

But while claims for carnosine's anti-aging effects sprint ahead of the science, some Australian researchers are taking the supplement seriously for other reasons as a potential ally against type 2 diabetes and a way to boost exercise performance.

"Although there's not much evidence in humans for an anti-aging effect, some studies of carnosine in humans have found that it improves insulin resistance, mood and cognition and a 2015 study of people with heart failure found it improved physical performance and quality of life," says Associate Professor Barbora de Courten of Monash University's School of Public Health and Preventive Medicine.

In a small study published last year she found that giving carnosine to people at risk of type 2 diabetes improved their insulin sensitivity and insulin secretion a sign that their bodies were better able to control blood glucose levels. Now she's begun a larger study to see if carnosine can help prevent or manage type 2 diabetes.

Carnosine's appeal is the evidence that it may improve some underlying factors that are common to many chronic diseases such as low-grade inflammation, oxidative stress and glycation a reaction between the body's protein and glucose that, over time, can damage the body's tissues, says de Courten, who's funded by the Heart Foundation.

"When we treat a disease with medication we usually target one specific problem or disease but what's interesting about carnosine is that it targets so many factors that seem to drive chronic diseases like heart disease, type 2 diabetes and dementia," she says.

"There's also evidence that carnosine improves exercise performance. As a doctor when you talk to patients about treating or preventing disease you usually talk about improving lifestyle first it may be that carnosine can also complement lifestyle changes."

But it's with short bouts of intense exercise that the evidence for carnosine is strongest, says sports scientist Dr Phil Bellinger, a senior researcher at Griffith University.

More carnosine on board helps muscles work harder for longer by staving off muscle fatigue caused by breakdown products of lactic acid but rather than taking carnosine itself, the advice is to take a supplement of beta-alanine one of two amino acids that make up carnosine in muscle.

"Beta-alanine intake is the best way to increase carnosine because L-histidine the other amino acid is already easily made by the body,"he says.

What types of exercise are likely to benefit from B-alanine?

"There's currently no proven effect in long distance sports but there's a benefit for short high intensity activities like sprint swimming, rowing, track cycling or middle distance running or activities involving repeated high-intensity effort like team sports, racquet sports and resistance training," says dietitian Tim McMaster of Sports Dietitians Australia.

Phil Bellinger's own research last year found that after four weeks of taking B-alanine daily, well-trained cyclists could train at a higher intensity, leading to better performance compared to cyclists taking a placebo.

"This may also apply to other types of high-intensity interval training and possibly CrossFit as long as the training alternates periods of working 'all out'with recovery periods or complete rest," he says.

Carnosine is also considered safe, although some people experience a tingling sensation in the skin when they take it, according to Sports Dietitians Australia.

But for gym goers and other recreational athletes hoping for a boost from B-alanine, Bellinger suggests checking other things first such as how well you train and eat.

"Before you try to get an advantage from a supplement, ask yourself if your training is as smart and hard as it could be, if you're eating a well-balanced diet and eating at the right time of the day."

Speaking of diet, carnosine is found in meat, poultry and fish but for vegetarians who work out regularly and are thinking of taking carnosine, McMaster says it's more important to make sure levels of other nutrients such as iron and B12 are okay.

But what science is learning about carnosine also underlines why maintaining muscle across the lifespan is so good for us not just to stay strong and independent but to defend against diabetes.

The carnosine in our muscles dwindles with age, kicked along by the loss of muscle fibre that comes with doing less high intensity activity or resistance training, Bellinger says.

"Yet there's evidence from animal studies that muscles high in carnosine have anti-diabetic qualities they can take up glucose more effectively and that helps to control levels of blood glucose."

Do you already have pre-diabetes or type 2 diabetes (controlled with diet or Metformin) and live in Melbourne? You might be interested in taking part in Dr de Courten's study of carnosine and diabetes at Monash Medical Centre. For more information call Josephine Johnson at 03 85722629 or email med-carnosineir@monash.edu

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Could this anti-ageing supplement help prevent diabetes? - The Sydney Morning Herald