Quantification of the major ω-3, ω-6 PUFAs using the Purdie assay and their ratios in different cholesterol types and the effects of gender and cholesterol on PUFA levels

This study used the Purdie assay, a new assay, to quantify the levels of omega-3 (ω-3) and omega-6 (ω-6) polyunsaturated fatty acids (PUFAs) in mol/L and the ratio of ω-6:ω-3 in Total cholesterol (TC), high-density lipoprotein cholesterol, (HDL-C) and low-density lipoprotein cholesterol (LDL-C) (referred to throughout as “non-HDL-C” in this study) fractions in 35 samples of human serum and also assessed the influence of gender and cholesterol types on levels of the analyzed PUFAs.Three principal components explained 89% of the total variance based on the variables measured. The ratio of ω-6:ω-3 PUFAs was significantly influenced by the type of cholesterol (F = 10.84, df = 2, 99, P = < 0.001) but not gender or interaction between gender and type of cholesterol, while the total PUFAs and the levels of ω-3 and ω-6 PUFAs were significantly influenced by gender, but age did not have a significant effect on the levels for total PUFAs.The findings of this study imply that, for males, more focus should be on the ratios of ω-6:ω-3 PUFAs in the non-HDL-C fraction and that the use of the ω-6:ω-3 ratio of PUFAs in serum is a better predictor of coronary heart disease than estimating LDL-C.

► Purdie assay can effectively be used for the analyses and quantification of PUFAs in human serum.
► The levels total cholesterol PUFAs can be used as predictor for good or bad cholesterol.
► ω-6: ω-3 ratio of PUFAs is a better predictor of CHD than estimating LDL-C.
► To the best of our knowledge this study is the first one of the kind.