We examine here the effect of cholesterol and triglycerides on the steady state shear blood flow rheology. We use the recent viscosity data of both high and low cholesterol/triglyceride donors reported by Moreno et al. (Korea-Aust Rheol J 27(1):1-10, 2015). We show that while the Casson model describes well the blood rheology, its model parameters need to be significantly modified from their physiological value expressions developed by Apostolidis and Beris (J Rheol 58(3):607-633, 2014). The modifications are parametrized with indices that all ratios: total cholesterol (TC) to high density pipoprotein (HDL), low-density lipoprotein (LDL) to HDL, and total triglyceride to HDL. These ratios, while they arise here naturally in the fitting of the data, they have all been previously identified as important in medical evaluations to cardiovascular diseases such as atherogenesis and stroke. We thus provide additional evidence for plausible causal link between cholesterol/triglycerides and cardiovascular conditions through their impact on blood flow rheology.