Given the need to put hundreds of studies into context, one would expect an extensive review. However, the authors only identified four “Core Trials” – performed in 1968, 1969, 1970, and 1979 – as suitable for consideration in reaching their conclusion. When the results of just these four studies are combined, the authors can demonstrate a statistical correlation between replacing saturated fats with polyunsaturated fats and reducing the “primary endpoint” related to cardiovascular disease defined by each trial.
In summary, randomized controlled trials that lowered intake of dietary saturated fat and replaced it with polyunsaturated vegetable oil reduced CVD by ≈30%, similar to the reduction achieved by statin treatment.
The Pukapuka and Tokelau Island study by Prior et al found a low incidence of CVD in the populations of these two islands, despite a large portion of energy intake (34% among Pukapukans and 63% among Tokelauans) and dietary fat intake being from coconut flesh. It has been reported that the diets of these two populations were low in sugar and high in fiber-rich foods, resulting in low cholesterol levels (4.5mmol/L and 4.6 mmol/L in Pukapukans and Tokelauans, respectively).
Want to improve your lipid profile, and your health? Cut out the sugar, and eat real food.