Page URL:

Inuit have unique genes for metabolising omega-3 fats

21 September 2015
Appeared in BioNews 820

Decades of advice on the protective effects of omega-3 fatty acids are being challenged by a study of the genomes of the Inuit population in Greenland.

The traditional diet of the Inuit primarily consists of proteins and fat from fish, with a comparatively low amount of vegetables and carbohydrates as a result of the extremely cold climate and sparse vegetation of the Arctic. The rate of heart attack and stroke is low among Arctic peoples, and this has lead health experts to conclude that omega-3 fatty acids are protective.

A new study has investigated whether this protection against heart attack might also be genetic. Researchers compared the genomes of 191 Inuit in Greenland, 60 Europeans and 44 ethnic Chinese to look for genetic changes that could benefit the Inuit population in their harsh environment.

'When we did that, it pointed directly to one group of genes where we had an extremely strong signal. They regulate how much of these omega-3s and omega-6s you make yourself naturally,' said Professor Rasmus Nielsen from the University of California, Berkeley, one of the authors of the paper, which was published in the journal Science.

Almost every Inuit in the study had variations in enzymes called fatty acid desaturases (FADS). These modulate fatty-acid composition, which may also affect the regulation of growth hormones. In contrast, only 25 percent of Chinese and two percent of Europeans had the same variations. Inuit people who had two copies of this variant gene not only had different levels of fatty acids in their blood, they were also, on average, one inch shorter and ten pounds lighter than those without the gene.

These variations may help to explain why some people are able to metabolise fats more effectively than others and what effects the same diet may have on different populations.

'The genetic network is rewired to make fewer of these [fatty acids] themselves,' Professor Nielsen told the New York Times. 'This clearly shows that you can't extrapolate [dietary effects] from the Inuit to other populations.'

Further research will be needed to show the full implications of having these variations, said Professor Nielsen. 'The regulation of fats in your body is a really complex network. You turn one knob, and it just changes everything everywhere else.'

Greenlandic Inuit show genetic signatures of diet and climate adaptation
Science |  18 September 2015
Human genes adapted to life in the Arctic
Eurekalert (press release) |  17 September 2015
Inuit Study Adds Twist to Omega-3 Fatty Acids’ Health Story
New York Times |  17 September 2015
Team Characterizes Genetic Adaptations to Diet, Cold in Greenland's Inuit Population
genomeweb |  18 September 2015
The Secret To The Inuit High-Fat Diet May Be Good Genes
npr |  17 September 2015
9 May 2016 - by Dr Özge Özkaya 
A study of ancient DNA obtained from prehistoric human remains has revealed details about modern humans before farming began, going back to their arrival in Europe around 45,000 years ago...
4 April 2016 - by Anastassia Bolotkova 
Researchers have found a genetic variant in populations that have favoured vegetarian diets over many generations...
2 November 2015 - by Klaus Mitchell 
How will the human race evolve over the next few hundred years? This is an interesting question that divides opinion among biologists. One such scientist, Professor Steve Jones, the famed British geneticist, recently discussed this topic with presenter Peter Snow on BBC Radio 4...
30 March 2015 - by Dr Meghna Kataria 
Scientists in Iceland have produced a comprehensive portrait of the nation's genetic makeup...
19 January 2015 - by Kirsty Oswald 
A twin study has shown that the majority of variation in immunity between individuals is due to non-genetic factors.
20 August 2012 - by Emma Stoye 
Eating two handfuls of walnuts every day can improve sperm quality in healthy young men, researchers have found...
19 March 2012 - by Sarah Pritchard 
Men who consume a diet rich in saturated fat - the type found in junk food - have lower sperm counts than men whose diets contain low levels of such fats, according to scientists...
11 October 2010 - by Matthew Smart 
Researchers in the US have shown that a gene-based test designed to predict the risk of Coronary Artery Disease (CAD) is only marginally better than existing methods....
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.