Brown Fat Breakthrough Could Be Key in Fight Against Obesity

Although it may not sound like it, brown fat is vital for your weight loss wellness. It is an energy-burning tissue that is important to your body’s ability to keep warm and regulate temperature, as well as being associated with lower obesity. Now, a new study from researchers at the Ottawa Hospital Research Institute, which was published in the prestigious journal Cell Metabolism, has discovered a way to turn muscle stem cells into brown fat, which could play a critical role in the fight against obesity.

Lead investigator Dr. Michael Rudnicki, senior scientist and director for the Regenerative Medicine Programme and Sprott Centre for Stem Cell Research, as well as a Canada Research Chair in Molecular Genetics and professor in the Faculty of Medicine at the University of Ottawa, commented, ‘This discovery significantly advances our ability to harness this good fat in the battle against bad fat and all the associated health risks that come with being overweight and obese.

Obesity is the fifth leading risk for death worldwide. According to the World Health Organisation (WHO), 2.8 million people die every year from the effects of being overweight or obese, and in Canada, where the study took place, the Public Health Agency of Canada estimates that 25% of Canadian adults are obese. In 2007, a study led by Dr. Rudnicki was the first to prove the existence of adult skeletal muscle stem cells. Now, the scientist has made another vital discovery; that these adult muscle stem cells not only have the ability to produce muscle fibres, but also to become brown fat.

The key to muscle stem cells becoming brown fat is a small gene regulator called microRNA-133, or miR-133. When miR-133 is present, your stem cells turn into muscle fibre, but these stem cells become brown fat when miR-133 is reduced. When the researchers injected mice with an agent to reduce miR-133, called an antisense oligonucleotide or ASO, the mice produced more brown fat, were protected from obesity and had an improved ability to process glucose. Dr commented, ‘While we are very excited by this breakthrough, we acknowledge that it’s a first step. There are still many questions to be answered, such as: Will it help adults who are already obese to lose weight? How should it be administered? How long do the effects last? Are there adverse effects we have not observed yet?’

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