increase the ratio of total to HDL cholesterol (Figure 4). The
products with the most favorable effect on this ratio are oils that
are rich in cis unsaturated fatty acids, such as rapeseed, soybean,
sunflower, and olive oils. The effects of the PUFAs, which
in our analyses consisted mainly of linoleic acid plus some
-linolenic acid, are more favorable than those of MUFAs such
as oleic acid, but the difference is slight. Our study did not
address the effects of n3 PUFAs from fish. Their major effect
on plasma lipids is to lower triacylglycerols (12), but their
favorable effects on CAD mortality may also involve pathways
other than plasma lipoproteins (92).
Apolipoprotein B and LDL particle size
There is evidence that not only the amount of cholesterol transported
by LDL particles but also the size and density of these particles
and their apo B content affect CAD risk (93). Effects of carbohydrates
on apo B were less favorable than those of unsaturated
fatty acids (Table 1), which may agree with the findings of studies
in which high-carbohydrate diets not only increased triacylglycerol
concentrations but also induced a shift toward smaller,
denser LDL particles (93).
Individual saturated fatty acids
Lauric acid markedly increases cholesterol, whereas stearic
acid lowers it somewhat when it is used to replace carbohydrates.
However, the picture reverses if one looks at total:HDL cholesterol:
both lauric and stearic acid are now more favorable than carbohydrates.
Lauric acid—a major component of tropical oils such
as coconut and palm kernel fat—has the largest cholesterol-raising
effect of all fatty acids, but much of this is due to HDL cholesterol.
As a result, lauric acid had a more favorable effect on
total:HDL cholesterol than any other fatty acid, either saturated
or unsaturated.
trans Fatty acids
The trans MUFAs were the most harmful macronutrient in
terms of the ratio of total to HDL cholesterol. If trans MUFAs
constituting 1% of energy are isoenergetically replaced with a
1:1:1 mix of carbohydrates, cis MUFAs, and cis PUFAs, then the