5 April 2024

When exposed to highly palatable (yummy) foods, some people overeat and have trouble regulating their intake long-term. 

Currently, 2 in 3 Australians are classified as being overweight or obese. This is about 12.5 million adults. Middle aged Australians have the worst statistics, with 8 in 10 men and 7 in 10 women between 45 and 54 years old being overweight or obese. 

Dr Robyn Brown, from the University of Melbourne, works at the challenging intersection of addiction, obesity and eating disorders. A few years ago, Dr Brown observed similarities between substance and food addiction. 

She secured an NHMRC Project Grant to explore how the brain is involved in overeating and potential new ways of treating obesity. As a result of the project, Dr Brown found the first direct evidence of brain impairments in obesity that parallel those observed in animal models of drug addiction. 

In drug addiction, long-term potentiation—the process where synapses strengthen through repetition—is impaired in the nucleus accumbens part of the brain, which is associated with reward and motivation. Dr Brown found that obese rats showed these similar impairments. 

‘Through my research, we have compelling preliminary data that show deficits in the brain associated with addiction are also found in diet-induced obesity. Therefore, strategies used to treat addiction, whether it’s drinking or gambling, can potentially be used to treat obesity,’ said Dr Brown.

The NHMRC grant also funded a preclinical trial of N-acetylcysteine (NAC), known to restore these specific ‘addiction-like’ brain deficits. Dr Brown tested NAC in a rat model and found it reduced compulsive eating of highly palatable foods. 

Her experiences have led her to work with health practitioners and advocate for a change in treatment approach. 

‘If you say to someone who has an addiction-like pathology, “Just stop eating”, it's like saying to someone who has alcohol use disorder, “Just stop drinking”. Change is not as easy as that,’ said Dr Brown.

‘It’s important to me that health practitioners realise that there’s more than choice going on here. Many people can have all the knowledge in the world, but they can’t control their behaviour.’

‘Showing that this is applicable in the obesity field is big because some people have not wanted to believe that the brain is involved. And that's my message: “Believe it; it's real”,’ said Dr Brown.

Findings from the NHMRC project have been incorporated into training for clinicians. And the preclinical findings regarding NAC represent a potential adjunct therapy to assist people to control their eating behaviour when engaging in other weight loss therapies.

‘The idea that we can get pharmacotherapies or strategies informed by addiction neuroscience through to the clinic and test them? That’s exciting,’ said Dr Brown.

Next steps:

Dr Brown is currently conducting a pilot trial of NAC in humans for compulsive eating and has found some positive preliminary results. She is seeking to conduct a larger clinical trial of NAC in humans and to also test a derivative of NAC, with higher bioavailability, preclinically. 

Dr Brown’s research laboratory is also conducting ongoing investigations to further understand:

  • the neurobiology associated with eating behaviours
  • how exposure to highly palatable food affects the brain and behaviour
  • the relationship between stress, emotion and eating behaviour and how it differs between males and females.
CIA

Dr Robyn Brown

Institution

University of Melbourne

Research title

A novel approach for the treatment of obesity: examining the potential of addiction therapeutics

Team

Professor Andrew Lawrence

Professor Peter Kalivas

Dr Diana Sketriene

Grant information

$765,935.00 

2016–2020

Project Grants

See also 10 of the Best.

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