September 24, 2021

I, Science

The science magazine of Imperial College

There are those among us, myself included, who explain away their inability to say no to one more drink or one more packet of biscuits by proclaiming that they have an ‘addictive personality’ which somehow makes their lack of self control socially acceptable.

Despite using this excuse many times myself, deep down I thought this trait to be purely psychological and just simply explained as an inherent lack of will power. However research at the University of Gothenburg may have identified a biological basis for why some people find alcohol and sugary treats so moreish!

The culprit is a neuropeptide called ghrelin, responsible for activating the brain’s reward system and increasing your appetite. It works like this:

  • Feeling hungry
  • Ghrelin levels increase
  • The brain’s reward system is activated
  • Our motivation to look for food increases

In previous studies, ghrelin has been associated with the development of alcoholism and drug addition. This new research, published in PLoS One, examined the genes of 579 members of the public. Those with certain changes in the ‘ghrelin gene’ were found to consume significantly more sugar and alcohol than other members of the sample population who did not have these specific changes. Blocking ghrelin in rats saw that they dramatically reduced their sugar consumption and were much less motivated to hunt for sugary snacks.

These same researchers had previously found that when the ghrelin system is blocked in humans, the positive effects of addictive drugs are greatly reduced lessening the chances of an individual succumbing to the addictive qualities.  The changes to the ghrelin gene found to be linked to higher levels of sugar consumption have also been associated with weight gain in alcoholics and smoking.

Now the real significance of this study is not just to confirm that my addictive personality may in fact have a biological basis. More importantly, it has brought scientists a step closer to understanding the physiological workings of addictive behaviour. From this research, new drugs can be developed to block the ghrelin system enabling the treatment of patients suffering from alcoholism and binge-eating disorders. On a societal scale, this could also help in persuading society to view alcoholism and other addictions as an illness, easing sufferer’s access to the much-needed treatment they deserve.