Treating sugar addiction to reverse obesity prevalence

Carbonated drinks - Photo R. Prasad

Like nicotine and cocaine, excess sugar consumption elevates dopamine levels, which control the brain’s reward and pleasure centres. – Photo: R. Prasad

In the last 30 years, the number of obese people in the world has been steadily increasing. According to the World Health Organisation, in 2014, more than 1.9 billion adults, 18 years and older, were overweight. Of these, over 600 million were obese. And 42 million children under the age of 5 were overweight or obese in 2013. In terms of percentage, 39 per cent of adults older than 18 years were overweight in 2014, and 13 per cent were obese.

A paper published in The Lancet on April 2, 2016 found that between 1975 and 2014 the age-standardised mean body mass index (BMI) in adults in 186 countries increased in both men and women.  The mean BMI in men increased from 21.7 kg/m² in 1975 to 24.2 kg/m² in 2014.  In the case of women, it increased from 22.7 kg/m² in 1975 to 24·4 kg/m² in 2014.

If excess sugar consumption has been shown to contribute directly to weight gain, thus leading to the obesity epidemic, researchers have found a novel strategy to reduce sugar consumption. A paper published on March 30, 2016 in PLOS ONE shows that, at least in mice, it might be possible to reduce sugar consumption by using certain medicines generally used for treating nicotine addiction to treat for sugar addiction.

Excess sugar consumption has been shown to behave the same way nicotine, cocaine and morphine work; it elevates dopamine levels, which control the brain’s reward and pleasure centres.

Like in the case of nicotine, long-term consumption of sugar tends to lower the dopamine levels thereby encouraging people to increase the amount of sugar consumed to achieve the same level of reward. And like nicotine and cocaine, withdrawing or stopping chronic sugar consumption can produce the same withdrawal symptoms as it results in imbalance in dopamine levels in the brain.

In the study, Masroor Sharff, the first author from the Queensland University of Technology at Translational Research Institute, Brisbane, Australia, and others used varenicline drug, which is used for treating nicotine addiction, for treating sugar addiction in animals.

Varenicline is an FDA-approved nicotinic acetylcholine receptor (nAChR) that reduces nicotine cravings and withdrawal symptoms. During the study, the researchers found that the drug significantly reduces sucrose consumption by modulating dopamine in the brain.

The animals in the study had access to sucrose either intermittently or continuously. Though further studies are warranted, the researchers note that only intermittent access to sucrose contributes to neurological changes.  And the varenicline drug was found to be effective in reducing sucrose craving when sucrose was made available intermittently.

Interestingly, the drug not only reduced sucrose consumption but also saccharin (artificial sweetener) consumption. “Our study also found that artificial sweeteners such as saccharin could produce effects similar to those we  obtained with table sugar, highlighting the importance of reevaluating our relationship with sweetened food per se,” said Dr. Shariff said in a release.

The researchers got similar results when other drugs such as mecamylamine and cytosine were used.