This recent Cochrane review
assessed the effects
of increasing omega-6 fats (linoleic acid, gamma-linolenic acid, dihomo-gamma-linolenic acid and arachidonic acid) on cardiovascular health, mortality,
lipids and adiposity, using previously unpublished data. 19 RCTs, including 6461 participants who were followed for one to eight years, were included.
The authors found no evidence that increasing omega-6 fats reduces cardiovascular outcomes other than myocardial infarction (MI) – where 53 people may
need to increase omega-6 fat intake to prevent 1 person from experiencing MI. High-quality evidence suggests increasing omega-6 fats reduces total serum
cholesterol, but not other blood fat fractions or adiposity.