Dietary n-3 alpha-linolenic and n-6 linoleic acids modestly lower serum lipoprotein(a) concentration but differentially influence other atherogenic lipoprotein traits: A randomized trial.
Study Goal
The researchers aimed to compare the effects of dietary alpha-linolenic acid (ALA) and linoleic acid (LA) on lipoprotein(a) [Lp(a)] and other atherogenic lipids, and to examine whether FADS1 rs174550 genotype modifies these responses.
Results Summary
ALA lowered serum Lp(a) by 7.3% and reduced LDL cholesterol, non-HDL-C, remnant-C, and apolipoprotein B more effectively than LA. Both diets showed greater absolute decreases in individuals with higher baseline Lp(a), but FADS1 genotype did not influence responses.
Population
118 men homozygous for FADS1 rs174550 SNP (TT or CC).
Effective Dosage
30-50 mL/day of Camelina sativa oil (ALA diet) or sunflower oil (LA diet), adjusted by BMI.
Duration
8-week intervention following a 4-week run-in period.
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
Camelina sativa oil (ALA diet) | decrease | serum Lp(a) concentration | 118 men homozygous for FADS1 rs174550 SNP (TT or CC) | 7.3% | lowered | #1 |
sunflower oil (LA diet) | decrease | serum Lp(a) concentration | 118 men homozygous for FADS1 rs174550 SNP (TT or CC) | 9.5% | lowered | #2 |
ALA diet | decrease | LDL cholesterol (LDL-C) | 118 men homozygous for FADS1 rs174550 SNP (TT or CC) | - | lowered | #3 |
ALA diet | decrease | non-HDL-C | 118 men homozygous for FADS1 rs174550 SNP (TT or CC) | - | lowered | #4 |
ALA diet | decrease | remnant-C | 118 men homozygous for FADS1 rs174550 SNP (TT or CC) | - | lowered | #5 |
ALA diet | decrease | apolipoprotein B | 118 men homozygous for FADS1 rs174550 SNP (TT or CC) | - | lowered | #6 |
FADS1 rs174550 genotype | no change | Lipid or lipoprotein responses | 118 men homozygous for FADS1 rs174550 SNP (TT or CC) | - | were not modified | #7 |
BACKGROUND AND AIMS: Lipoprotein(a) [Lp(a)] is a causal, genetically determined cardiovascular risk factor. Limited evidence suggests that dietary unsaturated fat may increase serum Lp(a) concentration by 10-15 %. Linoleic acid may increase Lp(a) concentration through its endogenous conversion to arachidonic acid, a process regulated by the fatty acid desaturase (FADS) gene cluster. We aimed to compare the Lp(a) and other lipoprotein trait-modulating effects of dietary alpha-linolenic (ALA) and linoleic acids (LA). Additionally, we examined whether FADS1 rs174550 genotype modifies Lp(a) responses. METHODS: A genotype-based randomized trial was performed in 118 men homozygous for FADS1 rs174550 SNP (TT or CC). After a 4-week run-in period, the participants were randomized to 8-week intervention diets enriched with either Camelina sativa oil (ALA diet) or sunflower oil (LA diet) 30-50 mL/day based on their BMI. Serum lipid profile was measured at baseline and at the end of the intervention. RESULTS: ALA diet lowered serum Lp(a) concentration by 7.3 % (p = 0.003) and LA diet by 9.5 % (p < 0.001) (p = 0.089 for between-diet difference). Both diets led to greater absolute decreases in individuals with higher baseline Lp(a) concentration (p < 0.001). Concentrations of LDL cholesterol (LDL-C), non-HDL-C, remnant-C, and apolipoprotein B were lowered more by the ALA diet (p < 0.01). Lipid or lipoprotein responses were not modified by the FADS1 rs174550 genotype. CONCLUSIONS: A considerable increase in either dietary ALA or LA from vegetable oils has a similar Lp(a)-lowering effect, whereas ALA may lower other major atherogenic lipids and lipoproteins to a greater extent than LA. Genetic differences in endogenous PUFA conversion may not influence serum Lp(a) concentration.