12 January - 20 June 2016

Omega-6 PUFA may reduce the risk of developing type 2 diabetes

Scientists are reporting in The Lancet, Diabetes & Endocrinology that consuming a diet rich in omega-6 polyunsaturated fat could significantly reduce the risk of developing type 2 diabetes.

Scientists are reporting in The Lancet, Diabetes & Endocrinology that consuming a diet rich in omega-6 polyunsaturated fat could significantly reduce the risk of developing type 2 diabetes.  Wu et al. report that major guidelines recommend that 5-10% of energy is obtained from linoleic acid, a predominant omega-6 PUFA. However, some researchers predict that linoleic acid might be harmful as it may compete with omega 3 PUFA or its metabolite arachidonic acid and might cause harmful effects, such as inflammation, leading to the increased risk of chronic diseases.

The aim of this current study was to "assess the associations of linoleic acid and arachidonic acid biomarkers with type 2 diabetes, with additional aims to assess factors that might modify these associations."  Wu et al. identified 20 prospective cohort studies that assessed circulating or tissue biomarkers of linoleic acid and arachidonic acid and incidence of type 2 diabetes.  The studies involved 39,740 adults from 10 countries, in whom 4347 new cases of diabetes occurred.  The participants in the studies were aged 18 years and older and did not have type 2 diabetes at baseline. Fourteen cohorts measured fatty acid biomarkers in phospholipids, six measured fatty acid biomarkers in total plasma or serum, four in cholesterol esters and 1 in adipose tissue.  The team report that “the median percentage of linoleic acid in total fatty acid in each cohort ranged from 8.3% in erythrocyte phospholipids to 54.5% in plasma cholesterol esters.  The median percentage of arachidonic acid in total fatty acid ranged from 0.3% in adipose tissue to 17.0% in erythrocyte phospholipids.”

After carrying out numerous statistical analyses, the team found that arachidonic acid biomarkers were not associated with incidence of type 2 diabetes overall.  However, biomarker levels of linoleic acid were inversely associated with incident type 2 diabetes. The scientists carried out categorical analysis and report that "the magnitude of the association between linoleic acid biomarkers and type 2 diabetes was substantial with high linoleic acid levels associated with a 43% lower relative risk of type 2 diabetes across quintiles."  

Wu et al. report that in a meta-analysis of 102 randomised feeding trails, dietary PUFAs were found to improve "glycaemia, insulin resistance and insulin secretion capacity compared with carbohydrate saturated fat and for some endpoints even monounsaturated fat".  Other studies have found that linoleic acid-rich vegetable oil reduced markers of inflammation.  The scientists state that their findings "do not suggest that high levels of dietary omega-6 PUFA are harmful.  Additionally, although omega-3 and omega 6 PUFA has been hypothesised to compete, we did not identify any evidence of a physiologically relevant interaction in this large, well powered consortium analysis".  

The Lancet, Diabetes & Endocrinology have published a comment by Gabriele Riccardi on the study who notes that "although this finding cannot immediately be extrapolated to linoleic acid intake, it seems reasonable to assume that the differences in the linoleic acid biomarker associated with this outcome would be consistent with linoleic acid intake corresponding to one serving of nuts or one spoonful of sunflower or corn oil daily. Epidemiological studies have shown that this amount of linoleic acid is associated with a reduced risk of type 2 diabetes."   

RSSL's Lipids Laboratory, part of the Investigative Analysis Team has expertise in all aspects of fat analysis and fatty acid profiling, including the determination of omega-3 and omega-6 fatty acids. To find out more please contact Customer Services telephone 0118 918 4076 or e-mail enquiries@rssl.com

share this article
RSSL endeavours to check the veracity of news stories cited in this free e-mail bulletin by referring to the primary source, but cannot be held responsible for inaccuracies in the articles so published. RSSL provides links to other World Wide Web sites as a convenience to users, but cannot be held responsible for the content or availability of these sites. This document may be copied and distributed provided the source is cited as RSSL's Food e-News and the information so distributed is not used for profit.

Previous editions

Load more editions

Make an Enquiry