As levels of obesity and binge drinking continue to soar in Europe, Scottish researchers have discovered Westerners may be genetically programmed to consume fatty foods and alcohol with a greater appetite than those in the East.
Scientists at the 黑料网 have uncovered a genetic 鈥榮witch鈥� which they believe makes Europeans far more likely to opt for high-fat food and alcohol than those in Asia.
Their findings 鈥� which also have implications for the treatment of depression 鈥� could 鈥榦pen up a world of new therapy options鈥� for what is rapidly becoming the 鈥榩lague鈥� of the Western world.
Scientists at the University鈥檚 Kosterlitz Centre compared the DNA of humans to that of mice and birds and found a genetic 鈥榮witch鈥� also known as an enhancer, that has remained unchanged for 300 million years.
This 鈥榮witch鈥� 鈥� a piece of DNA which turns genes on or off within cells 鈥� controls the galanin gene, which, when turned on in an area of the brain called the hypothalamus, regulates appetite and thirst.
Dr Scott Davidson, a native of Peterhead who found the 鈥榮witch鈥� said: 鈥淭here are 25,000 genes in every cell and these are nearly identical in all mammals - what makes us different from other species, and from each other, is when, where and by how much each of these genes are turned on or off during our development as embryos and in our lifetime.
鈥淣ot all cells turn on all genes all at once 鈥� something organises which genes are turned on in different cells and we call them enhancers or switches.鈥�
The team, led by Dr Alasdair MacKenzie, also noticed that the 鈥榮witch鈥� was different in some people and when they compared different racial groups they found that it had mutated and was weaker in 16 per cent of Europeans and 30 per cent of Asians.
Dr MacKenzie said: 鈥淭he switch controls the areas of the brain which allows us to select which foods we would like to eat and if it is turned on too strongly we are more likely to crave fatty foods and alcohol.
鈥淭he fact that the weaker switch is found more frequently in Asians compared to Europeans suggests they are less inclined to select such options.
鈥淭hese results give us a glimpse into early European life where brewing and dairy produce were important sources of calories during the winter months. Thus, a preference for food with a higher fat and alcohol content would have been important for survival. The negative effects of fat and alcohol we see today would not have mattered so much then as life expectancies were between 30-40 years.
鈥淚t is possible that during the winter individuals with the weaker switch may not have survived as well in Europe as those with the stronger switch and as a result those in the west have evolved to favour a high fat and alcohol rich diet.鈥�
The study, published in the respected Journal of Neuropsychopharmocology, also found that changes in the same 鈥榮witch鈥� were linked to depression.
Dr MacKenzie added: 鈥淕alanin is also produced in an area of the brain called the amygdala where it controls fear and anxiety. Thus, changing levels of galanin in the amygdala will have an effect on an individual鈥檚 emotional state. Intriguingly, the switch was also active in the amygdala.
The Aberdeen scientists worked alongside a team based in the Institute of Psychiatry in London led by Prof Peter McGuffin who recently conducted genetic studies on thousands of depressed patients.
鈥淭his study showed that the galanin gene is linked to depression and we show that part of a gene which is linked to depression is strongly linked to our switch.鈥� Dr MacKenzie added
In addition to the genetic studies his team has started to pick apart the machinery that control the switches.
Dr Davidson said: 鈥淭his has already allowed us to identify potential drug targets that will be used to develop a whole new generation of antidepressants as well as drugs to reduce cravings for fatty food and alcohol.鈥�.
Professor Ruth Ross, Head of the Kosterlitz centre was delighted with the findings of the project and said: 鈥淚t is now becoming obvious that the majority of the information in our DNA required for health does not reside in genes but in the vast uncharted areas of our DNA which tell the genes what to do鈥�.
鈥淭his study represents a major advance in our ability to understand how human genetic variation within this huge, murky and unexplored region of DNA contributes to disease susceptibility and places the 黑料网 at the very forefront of the field鈥�.