Sweet dreams: can you treat sugar as an addiction?

Drugs normally used to treat smoking and alcohol problems can reduce sugar cravings, a new study finds

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Putting down that doughnut can be a struggle when the reward pathways in your brain are egging you on, but medicating overeating like any other addiction could make this easier, a new study suggests.

A team of researchers at the Queensland University of Technology (QUT) are the latest group to apply anti-addiction drugs to the obesity problem. Their study, published in PLOS ONE on 30 March, shows for the first time that an FDA-approved smoking cessation drug, varenicline (or Champix), can lower sugar consumption in rats.

In the study, rats on a high-sugar diet reduced their intake of sucrose solution when administered with varenicline. This effect was particularly pronounced over the long-term, with rats significantly reducing their sucrose consumption by 12 weeks.

The drug is normally used to reduce nicotine cravings in humans by altering the mesolimbic reward pathway. Varenicline attaches to dopamine receptors in the brain, stimulating lower, more stable dopamine production.

This in turn blocks nicotine from binding to receptors, which would cause a spike in dopamine levels. QUT’s research suggests that the same mechanism could be used to dull the brain’s chemical reward for consuming sugar.

Professor Brian Oldfield, a metabolic neuroscientist at Monash University, said the study was an important proof of concept.

The use of a well-established drug such as varenicline gave the treatment an edge over newly approved medications, Professor Oldfield said. “[Varenicline] has been around for a while, presumably without any ill effects,” he said. “I would say that’s a plus. That’s a thumbs up for this.”

New weight loss drugs using similar mechanisms have been pulled off the shelves in the past due to serious side effects. One-time popular drug Rimonabant, for instance, was withdrawn in 2009 after it was linked to increased risk of depression and suicide.

Professor John Dixon, the head of the Clinical Obesity Laboratory, was more sceptical about associating obesity with addictive behaviour. While there were no doubt specific cases of food addiction, “that would be a long way from suggesting that obesity is driven by addiction for food”, he said.

Research had demonstrated that there were no patterns of addictive behaviour in obese populations. Also, addictive eating behaviour was often a manifestation of a different problem, such as insufficient protein in the diet, Professor Dixon said.

Giving overweight people insight into how their diet was aggravating their health problems was usually enough to induce a change. But treating obese people as addicts stigmatised them further and caused them to lose motivation to maintain a healthy diet, he said.

“Treating it as a physical addiction and to use drugs that do that may some have some efficacy, but they also may have some significant downsides.”