Effect of dietary fish supplementation on lipoprotein levels in patients with hyperlipoproteinemia

Effect of dietary fish was investigated in 51 study group patients and 50 age- and sex-matched control group patients, all with type II-b hyperlipoproteinemia. In the study and control group, 21 and 22 patients, respectively, had well regulated non-insulin dependent diabetes mellitus. Neither the study group nor control group patients smoked or consumed alcohol beverages. Blood pressure was within normal limits (16/11-20/12 kPa) in both groups. During a six-month study period, the study group took 0.5-1 kg breaded pilchard per week, whereas the control group patients were on their standard hypolipoproteinemic diet. The following parameters were determined in both study and control group patients before the study, every 3 months during the study, and 3 months after the completion of the study, total cholesterol, HDL cholesterol (HDL2 and HDL3), LDL cholesterol, VLDL cholesterol, triglycerides, blood glucose and uric acid. Fish intake was found to statistically significantly decrease the levels of total cholesterol (-10.7%), LDL cholesterol (-11.7%), VLDL cholesterol (-14.8%) and triglycerides (-12.3%) (p < 0.05), whereas a statistically significant increase was observed in the levels of HDL cholesterol (+5.3%) and HDL3 (+7.4%) (p < 0.05). Three months after the completion of the study, when the study group patients had resumed their standard hypolipoproteinemic diet without extra fish intake, the levels of lipoprotein fractions returned to those recorded before the study. There were no statistically significant changes in the levels of blood glucose, uric acid and HDL2. In the control group, no statistically significant changes in lipoprotein fractions were recorded. Our findings suggested that dietary intake of 0.5-1 kg fish containing a small amount of omega-3 fatty acids, along with the standard hypolipoproteinemic diet, may decrease the level of atherogenic lipoprotein fractions, and increase the level of lipoprotein protective fractions, thus reducing or at least delaying the development of atherosclerosis.