ed fats and excess consumption of saturated fats and refined carbohy-
drates lower HDL.
More importantly, the recommendation that people substitute
polyunsaturated fats for saturated can be devastating for HDL levels.
If the ratio of polyunsaturated fat to saturated fat exceeds 2 (a ratio of
2:1), HDL levels usually diminish, raising your cardiac risk. If your A,
B and C fats are balanced, as discussed in Chapter 10,you avoid dis-
turbing this ratio. Due to the heavy marketing of polyunsaturated oils
since the 1970s, American diets now contain twice the polyunsaturat-
ed oil compared to diets of the 1950s and 60s. In addition, body-fat
samples today show that levels of linoleic acid (an A fat) are at twice
what they were 40 years ago.
The ‘Bad’ Cholesterol
LDL cholesterol — low-density lipoprotein — is known as the “bad”
cholesterol. A recent trend in preventative medicine is to stress lower-
ing LDL cholesterol with drugs. But it’s really not the LDL itself that
causes the potential harm or risk. It’s only when LDLoxidizes that it
deposits in your arteries. Oxidation of LDLresults from free radicals,
in much the same way that iron rusts. While lowering LDL levels can
make less of it available for oxidation, antioxidants from vegetables
and fruits can help prevent oxidation. In addition, many of the factors
just mentioned that raise HDL also lower LDL, the reason these plant
foods can significantly lower your risk of heart disease. LDL is best
measured when blood is drawn after a 12-hour fast for an accurate
evaluation.
Excess dietary carbohydrates can especially adversely affect LDL
levels. This is due to excess triglycerides from carbohydrates produc-
ing more, smaller, dense, LDL particles, which are even more likely to
clog arteries.
In addition, a lower intake of dietary cholesterol is linked to an
increase of these more dangerous LDL particles. And to make matters
worse, these types of LDL particles are also associated with the inabil-
ity to tolerate moderate to high levels of dietary carbohydrates (i.e.,
insulin resistance) even in relatively healthy individuals.
THE BIG PICTURE OF HEART DISEASE • 317