In July 2018 researchers from UK published their review of the medical scientific literature to assess the effect of increasing omega-6 polyunsaturated fatty acids on cardiovascular disease. A total of 19 studies involving 6,461 individuals were included in the review. Results showed that there was no real evidence that increasing omega-6 fats reduced cardiovascular outcomes other than for heart attack, where it was assessed that 53 people may need to increase omega-6 polyunsaturated fatty acid intake to prevent 1 person from experiencing a heart attack. Therefore, although the benefit of omega-6 polyunsaturated fatty acids remains to be proven, increasing them may be of benefit in people at high risk of a heart attack. There was high quality evidence that increased omega-6 polyunsaturated fatty acids reduced total cholesterol levels a little in the long term but they made little or no difference to serum triglycerides, HDL (good)- or LDL (bad)-cholesterol levels. In addition, increasing omega-6 polyunsaturated fatty acids was found to have little or no effect on obesity.
Hooper L et al. Omega-6 fats for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev. 2018 Jul 18;7:CD011094.