Chapter 3, Problem 3DAA

Effects of Dietary Fats on Lipoprotein Levels

Cholesterol that is made by the liver or that enters the body from food cannot dissolve in blood, so it is carried through the bloodstream in clumps called lipoprotein particles. Low-density lipoprotein (LDL) particles carry cholesterol to body tissues such as artery walls, where they can form deposits associated with cardiovascular disease. Thus, LDL is often called “bad” cholesterol. High-density lipoprotein (HDL) particles carry cholesterol away from tissues to the liver for disposal, so HDL is often called “good” cholesterol. In 1990, Ronald Mensink and Martijn Katan published a study that tested the effects of different dietary fats on blood lipoprotein levels. Their results are shown in FIGURE 3.2.

FIGURE 3.2 Effect of diet on lipoprotein levels. Researchers placed 59 men and women on a diet in which 10 percent of their daily energy intake consisted of cis fatty acids, trans fatty acids, or saturated fats.

The amounts of LDL and HDL in the blood were measured after three weeks on the diet; averaged results are shown in mg/dL (milligrams per deciliter of blood). All subjects were tested on each of the diets. The ratio of LDL to HDL is also shown.

An elevated risk of heart disease has been correlated with increasing LDL-to-HDL ratios. Which group had the highest LDL-to-HDL ratio?