40-Year-Old Data Cast Doubt on Dietary-Fat Guidance

By Joe Elia

Data recovered from an old trial confirm the increased risks of substituting dietary omega-6 linoleic acid (ω-6 LA) for saturated fats, calling American Heart Association advice into question. The data appear in BMJ.

Cardiovascular outcome data from the 1966–1973 Sydney Diet Heart Study were analyzed for the first time. The trial, conducted among some 450 men with recent coronary events, tested the effect of replacing dietary saturated fats with ω-6 LA. Reports after the end of the trial showed increased all-cause mortality among those receiving ω-6 LA. The recovered data, which had been stored on tape, also show increased risks for mortality from cardiovascular disease (hazard ratio, 1.70) and coronary disease (1.74).

An editorialist writes: "These findings argue against the 'saturated fat bad, omega-6 [polyunsaturated fatty acid] good' dogma."