People vary widely in how their bodies respond to dietary changes. In some people—call them responders—cholesterol levels closely reflect the amount of unhealthy fats in their diets. In others—nonresponders—cholesterol levels more closely reflect how much cholesterol their livers make rather than how much they consume.
A study done in 1997 at the Human Nutrition Research Center on Aging at Tufts University looked at how 120 men and women responded to a low-fat, low-cholesterol diet recommended by the NCEP, called the NCEP Step Two diet. On average, LDL levels dropped. Yet even though everyone ate the same thing—the researchers provided the volunteers with all their food and drink—the average result masked a wide range of LDL responses, ranging from a 55% decrease to a 3% increase among men, and a 39% decrease to a 13% increase among women.
There are two important messages from the research on responses to dietary fat and cholesterol:
Determine whether dietary changes work for you. Say your cholesterol is creeping up into the high range, and your physician suggests that you try a lower-fat, lower-cholesterol diet for three to six months. You make an effort to do so. But at the end of the trial period, a blood test shows that your cholesterol levels haven't budged. Your physician might misinterpret the lack of change and chide you for not sticking with the new diet. But if you have followed the diet carefully, make sure the doctor knows it. You may belong to the nonresponder group and need a different kind of diet, or medication, to control your cholesterol.
One size doesn't fit all. When a friend or relative tells you how much his or her cholesterol level dropped after trying a particular diet, you may be tempted to try the same diet. But if after a few months you discover that the diet has no effect, chalk it up to genetic and physiological differences. There just isn't a one-size-fits-all recommendation for diet or cholesterol consumption, which means you may have to try several different approaches to find one that works for you.