12 Oct 2017 --- The risk of developing Type 2 diabetes could be significantly reduced by eating a diet rich in omega 6 polyunsaturated fats, a new study suggests. These findings, published in The Lancet Diabetes & Endocrinology, shed new light on the potential health benefits of omega 6, which is found in bean and seed oils such as soybean and sunflower oils and in nuts. They also support clinical recommendations to increase dietary intake of omega 6 rich foods.
“Our findings suggest that a simple change in diet might protect people from developing Type 2 diabetes which has reached alarming levels around the world,” says lead author Dr. Jason Wu of The George Institute for Global Health in Sydney.
“This is striking evidence,” remarks senior author and Professor Dariush Mozaffarian of the Friedman School of Nutrition Science and Policy at Tufts University in Massachusetts.
“The people involved in the study were generally healthy and were not given specific guidance on what to eat. Yet those who had the highest levels of blood omega 6 markers had a much lower chance of developing Type 2 diabetes,” Mozaffarian adds.
Little evidence for negative health effects
Recent studies have raised concerns that omega 6 may have negative health effects, such as inflammation leading to the increased risk of chronic diseases, according to The George Institute for Global Health’s press release.
However, when the global collaboration led by The George Institute explored these concerns in studies from around the world, they found that individuals who had the highest blood level of linoleic acid, the major omega 6 fat, were 35 percent less likely to develop Type 2 diabetes in the future than those who had the least amount.
Researchers analyzed data from 20 studies involving 39,740 adults from 10 countries, in whom 4,347 new cases of diabetes occurred over time. These included adults with a wide range of ages and without any diagnosis of Type 2 diabetes at the onset of the studies, when they were laboratory tested for levels of two key omega-6 markers – linoleic acid and arachidonic acid.
Linoleic acid was associated with lower risk, while levels of arachidonic acid were not significantly associated with either higher or lower risk of diabetes.
“Some scientists have theorized that omega 6 is harmful to health,” says Dr. Wu. “But based on this large global study, we have demonstrated little evidence for harms, and indeed found that the major omega 6 fat is linked to lower risk of Type 2 diabetes.”
Linoleic acid is not formed in the body and can only be obtained from the diet. US dietary guidelines recommend between 5 to 10 percent of energy should be derived from polyunsaturated fats.
“Based on concerns for harm, some countries recommend even lower intakes,” says Dr. Wu. “Our results suggest that eating foods rich in linoleic acid may lower risk of Type 2 diabetes.”
The George Institute for Global Health press release notes that the research combined many large observational studies, and therefore it could not directly determine the effect of raising omega 6 fat levels in a trial.
The institute adds that the study’s strengths include the use of objective blood or tissue biomarkers of fatty acids, that avoid memory errors associated with people's own impressions of their diet; that researchers developed a pre-specified standardized analysis protocol, which increases consistency of the findings; and that data from many countries around the world was included, enhancing the relevance to different populations.
Previous omega 6 studies reported by NutritionInsight have linked omega 6 to lower mortality in older men and protection against schizophrenic symptoms in offspring.