<P> Fasting serum lipids have been associated with short term verbal memory . In a large sample of middle aged adults, low HDL cholesterol was associated with poor memory and decreasing levels over a five - year follow - up period were associated with decline in memory . </P> <P> While higher HDL levels are correlated with cardiovascular health, no medication used to increase HDL has been proven to improve health . In other words, while high HDL levels might correlate with better cardiovascular health, specifically increasing one's HDL might not increase cardiovascular health . The remaining possibilities are that either good cardiovascular health causes high HDL levels, there is some third factor which causes both, or this is a coincidence with no causal link . </P> <P> HDL lipoprotein particles that bear apolipoprotein C3 are associated with increased, rather than decreased, risk for coronary heart disease . </P> <P> Certain changes in diet and exercise may have a positive impact on raising HDL levels: </P>

What are the functions of hdl cholesterol in the bloodstream