Since fat has been labeled as a culprit, several preventive health advocates have taken the approach that extreme dietary fat reductions to 10% or less of total caloric intake might be better.

Two recent studies, however, contradict this philosophy.

Knopp et al (JAMA-November 12, 1997) published a study looking at 444 hypercholesterolemic men. He found that a reduction in fat intake below 26-28% total caloric intake not only failed to lower cholesterol further, but was actually less effective in cholesterol reduction than the moderate fat diet. He also found that in many cases the more restrictive low fat diets resulted in a lowering of the good or HDL cholesterol and a rise in triglycerides. Both low HDL levels and high triglycerides have been linked to an increased incidence of coronary heart disease.

Gillman et al (JAMA-December 24, 1997) published a study looking at 832 middle aged men and found that reductions in total fat and, in particular, reductions in saturated and monounsaturated fat were associated with an increased incidence of ischemic strokes. Reduction in polyunsaturated fats did not appear to play a role. These findings are consistent with studies on Japanese men who consume diets with little dietary fat (~10%). These men have low rates of coronary heart disease but a much higher rate of stroke. Examining the data presented by Gillman it appears that the risk of stroke increases significantly when dietary fat intake is reduced below ~32% total caloric intake.

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