Implications For Diet: Dietary Lipids and LDL Levels
An early incarnation of the lipid hypothesis which focused on hypercholesterolemia lead to the suggestion that mortality from CHD might be reduced by controlling dietary input of cholesterol. Studies have demonstrated that increasing dietary cholesterol leads to an increase in both total cholesterol (TC) and LDL Cholesterol (LDL-C), however it also leads to increases in the level of high-density lipoprotein cholesterol (HDL-C), offsetting the effect of the increase in LDL-C. Epidemological studies which attempted to correlate dietary cholesterol with risk of mortality in CHD have produced mixed results.
Recent studies have focused more on the ratio of saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) in the diet. It has been demonstrated that intake of SFA raises TC in humans, whereas PUFA lowers TC; however SFA also increases the level of HDL-C, once more offsetting the effect of increased TC. Studies of individual fatty acids show that some SFAs, e.g. stearic acid and palmitic acid have little effect of LDL-C levels; stearic acid actually lowers the LDL/HDL ratio due to a greater increase of HDL-C levels relative to TC.
Epidemiological studies designed to test the relationship between high SFA/PUFA ratios and CHD mortality have tended to produce mixed results. Two recent studies provide an example of this lack of consensus: a study from Poland correlated a decline in CHD mortality with a decrease in the ratio of SFA to PUFA in the population's diet following the collapse of communism. Yet a large population study from Sweden covering roughly the same time period showed no association between fat intake and CHD.
Read more about this topic: Chronic Endothelial Injury Hypothesis
Famous quotes containing the words implications and/or levels:
“Philosophical questions are not by their nature insoluble. They are, indeed, radically different from scientific questions, because they concern the implications and other interrelations of ideas, not the order of physical events; their answers are interpretations instead of factual reports, and their function is to increase not our knowledge of nature, but our understanding of what we know.”
—Susanne K. Langer (1895–1985)
“The word which gives the key to the national vice is waste. And people who are wasteful are not wise, neither can they remain young and vigorous. In order to transmute energy to higher and more subtle levels one must first conserve it.”
—Henry Miller (1891–1980)