Population and individual level results for saturated fat, serum cholesterol and CHD in the Zutphen and the Seven Countries Study

In 1960 the average saturated fat intake of the middle-aged men in Zutphen was high and amounted to 18% of energy with a relatively small standard deviation of 3% of energy. Dietary saturated fat was not associated with serum cholesterol and 10-year CHD mortality in the Zutphen Study. But in contrast, among populations of the Seven Countries Study showed that the average saturated fat intake, average serum cholesterol level and 10-year CHD mortality rates in the 16 cohorts were strongly correlated.

Why this difference?

The strong correlations of population levels of dietary saturated fat and serum cholesterol with CHD mortality in the Seven Countries Study overall was due to large variations in average saturated fat intake, average serum cholesterol level and CHD mortality rates among the 16 cohorts. In the Zutphen Study saturated fat intake of individuals was not related to either serum cholesterol or CHD mortality. The zero correlations were the consequence of a small range in dietary saturated fat among the Zutphen men along with the large day-to-day variation within these men (see the graphs and Jacobs et al 1979).

Interpretation

At the individual level multiple saturated fat measurements are needed to obtain positive associations of saturated fat intake with serum cholesterol and CHD.