Additive effect of linseed oil supplementation on the lipid profiles of older adults

Background: Linseed oil has been investigated as a rich source of n-3 series polyunsaturated fatty acids, which mainly produce a non-atherogenic lipid profile. The objective of this study was to investigate the effect of linseed oil supplementation associated with nutritional guidelines on the lipid profiles of older adults, according to the intake of saturated fatty acids (SFA). Methods: We conducted a double-blind, placebo-controlled clinical trial with 110 older adults randomized in two groups: placebo and linseed oil. The linseed oil group received supplementation with 3 g of linseed oil. Both groups received nutritional guidance and were supplemented for 90 days with monthly blood collection for biochemical analysis. The dietary intake of saturated fat was subdivided into low (<7% SFA/day of the total energy value) and high consumption groups (>7% SFA/day of the total energy value). Results: Low SFA (<7% SFA/day of total energy value) consumption was associated with lower total cholesterol concentrations. However, we observed that the linseed oil group, including older adults who consumed >7% SFA/day, had a greater reduction in total cholesterol than the placebo group (P=0.020). The same was observed for low-density lipoprotein (LDL) cholesterol (P<0.050), suggesting an additive effect of linseed oil and diet. High-density lipoprotein (HDL) cholesterol concentrations were increased significantly in only the linseed group, suggesting that the nutritional intervention alone did not improve HDL cholesterol. Conclusion: The results suggest that the nutritional intervention was effective, but linseed oil showed notable effects by increasing the HDL cholesterol concentration. In addition, consumption of <7% SFA/day of the total energy value increased the effect of linseed oil, demonstrating the importance of reducing the consumption of saturated fat.