LDL and apoB
Flaxseed oil lowers small dense LDL alongside CETP and apoB concentrations after twelve weeks in Japanese men (Nutr J 2015)
Original title: Flaxseed oil intake reduces serum small dense low-density lipoprotein concentrations in Japanese men: a randomized, double blind, crossover study
In a randomized, double-blind crossover study, 15 Japanese men took 10 g daily of flaxseed oil (5.49 g alpha-linolenic acid) or corn oil (0.09 g) for 12 weeks each, with lipids and lipoproteins measured at baseline, 4, and 12 weeks. At 12 weeks, CETP and apoB concentrations were significantly lower in the flaxseed oil period than the corn oil period, and small dense LDL cholesterol was significantly reduced during flaxseed oil supplementation at both 4 and 12 weeks, with no effect from corn oil. Among subjects with triglycerides above 100 mg/dL, flaxseed oil markedly reduced small dense LDL at both timepoints compared with baseline, indicating flaxseed oil's cardiovascular benefit includes lowering CETP alongside its established sd-LDL-lowering effect.
Original abstract
Background: The effects of alpha-linolenic acid (ALA) on cardiovascular risk factors considerably vary between published reports. Therefore, we investigated the effects of 12-week supplementation with flaxseed oil (FO), which is a rich source of ALA, on cardiovascular risk factors such as serum small dense low-density lipoprotein (sd-LDL) concentrations.
Methods: In a randomized, double blind, crossover study, 15 subjects ingested 10 g of FO or corn oil (CO), containing 5.49 g and 0.09 g of ALA, respectively, once daily with dinner. Blood samples were collected at 0, 4 and 12 weeks, and were used for analysis of serum lipid, lipid-related proteins, serum fatty acids and serum sd-LDL cholesterol. Differences during the test period were identified using a repeated-measures analysis of variance (ANOVA) for within-group effects. Group differences were identified using paired t-test at each blood sampling time point.
Results: ALA and eicosapentaenoic acid concentrations were significantly higher in the FO period at 4 and 12 weeks than in the CO period. No significant differences in docosahexaenoic acid concentrations were observed between two periods, and cholesteryl ester transfer protein and apolipoprotein B concentrations were significantly lower in the FO period than in the CO period at 12 weeks. FO supplementation was associated with a significant decrease in sd-LDL concentrations at 4 and 12 weeks, and CO supplementation had no effect. Moreover, sd-LDL concentrations were significantly lower in the FO period than in the CO period at 4 weeks. Among subjects with triglyceride (TG) concentrations of >100 mg/dl, FO supplementation markedly reduced sd-LDL concentrations at 4 and 12 weeks compared with baseline. Sd-LDL concentrations significantly differed between the periods at both 4 and 12 weeks.
Conclusion: This study indicates that the FO, which is a rich source of ALA, leads to lower sd-LDL cholesterol concentrations.
Summary written by cetpinhibition.org from the published abstract; figures as published. Page updated 19 August 2026. Methods.