Monash University scientist Tony Tiganis may yet hold the key in the fight against obesity. Tiganis and his team have been researching the connection between two naturally occurring hormones, which he says has given scientists new insights into how the brain regulates body fat.
With obesity rates rising, accelerating obesity related illnesses, the push for a cure is becoming increasingly demanding. In Australia alone, approximately two-thirds of the population is overweight, and roughly one-third is obese, costing the economy in excess of $56 billion annually.
The process conjured by Tiganis relates to leptin – a hormone produced by fat acting to suppress hunger – and insulin – produced by the pancreas in response to the levels of glucose in the blood – after a meal.
Both of these hormones convey to the brain the amount of energy stored in the body and how much more is likely to be stored as a result of consumption. Once the energy levels are received by the brain the body converts white fat (storage) into brown fat (energy burn).
Tiganis has seen effective results in studies on mice to suggest that this process may actually be the cause of weight gain and obesity.
“We believe that one potential reason for why we may get fat is that this mechanism of energy balance is altered because the brain does not respond to insulin and leptin and does not effectively promote the conversion of white fat to brown fat.
“In mice we’ve been able to show that if we instruct the brain to convert white fat to brown fat, mice don’t put on weight when they are fed a high fat diet and are metabolically healthy,” Tiganis told Neos Kosmos.
Whilst conclusive evidence is still years away, early signs of a ‘cure’ are positive.
“We’ve generated genetically engineered mice that lack two molecules that inhibit the action of insulin and leptin, and we found the responses were enhanced and the mice had high levels of brown fat and were resistant to diet induced obesity. So we fed them a high fat diet and they simply didn’t put on weight – and this cannot be explained by changes in their activity. They didn’t move around more, they didn’t eat less, this can be explained solely by the increase in brown fat, the conversion of white fat into brown fat and the increase in energy expenditure.”
He said factors behind the energy imbalance in obesity are multifactorial, but hopes to eventually harness the ability to promote the conversion of white fat to brown fat.
One of the stumbling blocks, he said, is the inability to test the human brain according to the same process trialled in mice.
“No-one’s really prepared to give up their brain. So we need to do a lot more work in mice, then we start looking at humans and come up with ways to manipulate this pathway. There’s nothing at this stage to be gained from our studies in terms of helping out individuals,” he said.
With effective obesity drugs still years away, for now Tiganis recommends regular exercise, a good healthy diet and limited carbohydrate intake as the keys to combating fat levels.