#502: Sydney Diet-Heart Study – Is Linoleic Acid Causing Heart Disease?

Links: Go to episode page (with study links) Subscribe to Premium Past episodes referenced: Episodes 493, 481 & 317 Further reading: How Diet Influences Heart Disease Risk About This Episode: The Sydney Diet-Heart Study was a clinical trial conducted in the 1960s and 1970s that aimed to examine the hypothesis that reducing saturated fat intake in the diet would lead to a reduced risk of heart disease. However, it really only gained attention after a more recent re-analysis by Ramsden et al., which in recent years has been used as supporting evidence for the idea that increased polyunsaturated fat (PUFA), and specifically linoleic acid, in addition to reduced saturated fat intake, can increase heart disease risk. This was based on the findings that substituting linoleic acid in place of saturated fat increased all-cause, CVD and CHD mortality. This is of course counter to prevailing consensus and guidelines in this area, which routinely show reduced risk on replacing SFA with PUFA. Could this trial undermine the common conclusions that replacing saturated fat with polyunsaturated fat decreases heart disease risk? In this episode Alan and Danny discuss some of the crucial aspects to understand about this study and what it means for what conclusions can be made about the impact of PUFA broadly, and linoleic acid specifically, on our health.