Differential effect of high dietary fat intakes on haemorheological parameters in rats

High dietary intake of fats has been thought to be one of the major risk factors for the development of CVD. Less is known about the possible influence of fats from various sources on haemorheological abnormalities, which are considered an important factor in the pathogenesis of these diseases. The goal of the present study was to investigate effects of high-fat diets enriched in unsaturated fatty acids (USFA), SFA or trans-fatty acids (TFA), respectively, on haemorheological parameters in rats. Wistar female rats were divided into four groups and fed diets based on the AIN-93M formulation containing approximately 10 % energy from soyabean oil (control group) or 40 % energy from soyabean oil (USFA), palm oil (SFA) and vegetable shortening (TFA) for 8 weeks. The results showed that rats fed high-fat diets exhibited significant increases in serum TAG levels (P < 0.01), plasma viscosity (P < 0.01), whole blood viscosity (P < 0.01) and internal viscosity (P < 0.01) compared to the controls. The TFA group showed a significant decrease in erythrocyte deformability (P < 0.01) and increase in internal viscosity (P < 0.01) compared with the other groups. In addition, a significant increase in blood levels of free radicals (P < 0.01) was found in the TFA group, suggesting that the attack of oxygen-free radicals could be responsible for the impaired erythrocyte deformability. These impairments could be partly responsible for the development of various circulatory disorders. The present haemorheological study provides additional insights into the potential adverse effects of trans-fat and high-fat diets on haemorheological parameters.