Dr. David Diamond is a neural scientist who has got himself into a second career of researching on cardiovascular diseases (CVD) and cholesterol. This was because he found in 1999 that his triglyceride (TG) was about 800, his HDL was about 30, and thus his CVD risk is much much higher than regular people. In order to get back his own health, he started to exercise like crazy and followed dietary guidelines, but only found that he had even higher TG, lower HDL and gained more weight at 2007. Since then he started a long journey of digging into thousands of papers on CVD research and made himself an expert in this area. His gave a talk at the 2019 CrossFit Health Conference titled "Deception of Cholesterol Research: Separating Truth from Profitable Fiction". Here are some interesting points he pointed out.
Does dietary saturated fat cause CVD? The answer is no. An 1961 paper compared the same patient's plasma under high-carb diet and high-fat diet. The plasma is fatty with high-carb diet, while it is clear under high-fat diet. So eating more fat does not put more fat in the blood stream.
Does cholesterol, especially LDL-C cause CVD? The answer is also no. Revisiting the very important 1985's paper on MRFIT study, he found that although the relative risk (red bars in graph) was said to be 4x higher with cholesterol level of 290mg/dL or higher, than with cholesterol level of 150mg/dL, the absolute difference was only 1%. The original data in blue show that people who did not die from CVD were 99.7% at low end vs. 98.7% at high end. Thus, people who died from CVD were 0.3% vs. 1.3%. Taking the ratio between 1.3% and 0.3%, the relative risk of 4X is obtained. So the risk is exaggerated.
Does high cholesterol limit people's lifespan? Not really. Norway, Honolulu and other studies show elder people with higher cholesterol live longer than the ones with lower cholesterol. Interesting!
To be continued.
Comments