I found that butter made me faster at arithmetic. This contradicted the usual view that butter is unhealthy. However, there is plenty of evidence that the usual view is wrong. The latest issue of the American Journal of Clinical Nutrition contains another example. An epidemiological article titled “Dietary intake of saturated fat by food source and incident cardiovascular disease: the Multi-Ethnic Study of Atherosclerosis” found a negative correlation between dairy fat and heart disease:
Although dietary recommendations have focused on restricting saturated fat (SF) consumption to reduce cardiovascular disease (CVD) risk, evidence from prospective studies has not supported a strong link between total SF intake and CVD events. . . . After adjustment for demographics, lifestyle, and dietary confounders, a higher intake of dairy SF was associated with lower CVD risk [HR (95% CI) for +5 g/d and +5% of energy from dairy SF: 0.79 (0.68, 0.92) and 0.62 (0.47, 0.82), respectively].
However, saturated fat from meat was associated with more heart disease:
In contrast, a higher intake of meat SF was associated with greater CVD risk [HR (95% CI) for +5 g/d and a +5% of energy from meat SF: 1.26 (1.02, 1.54) and 1.48 (0.98, 2.23), respectively].
It isn’t obvious how to explain the interaction (the direction of association of saturated fat depends on whether it is in dairy or meat). The authors conclude:
Associations of SF with health may depend on food-specific fatty acids or other nutrient constituents in foods that contain SF, in addition to SF
This recent article also questions the idea that dairy fat causes heart disease. One more reason to question conventional nutritional advice.