Inflammatory response to dietary linoleic acid depends on FADS1 genotype.
Study Goal
The researchers aimed to determine whether the FADS1 rs174550 genotype modifies metabolic responses to dietary linoleic acid (LA) intake, particularly on plasma fatty acid composition, fasting glucose, and hsCRP levels.
Results Summary
The study found that the FADS1 genotype influenced metabolic responses to an LA-enriched diet, with differences in hsCRP, fasting glucose, and arachidonic acid proportions between genotype groups. TT homozygotes showed correlations between plasma eicosanoids, arachidonic acid, and hsCRP, while CC genotypes did not.
Population
1337 men from the Metabolic Syndrome in Men cohort, with 62 healthy men (TT or CC genotype for FADS1 rs174550) in the intervention trial.
Effective Dosage
Not specified
Duration
4 weeks
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
LA-enriched diet | increase | plasma LA proportion | healthy men homozygotes for the TT or CC genotype of the FADS1 rs174550 | - | increased | #1 |
LA-enriched diet | neutral | serum hsCRP concentrations | healthy men homozygotes for the TT or CC genotype of the FADS1 rs174550 | - | responses differed between genotype groups | #2 |
LA-enriched diet | neutral | plasma fasting glucose concentrations | healthy men homozygotes for the TT or CC genotype of the FADS1 rs174550 | - | responses differed between genotype groups | #3 |
LA-enriched diet | neutral | proportion of arachidonic acid (20:4n-6) in plasma phospholipids and cholesteryl esters | healthy men homozygotes for the TT or CC genotype of the FADS1 rs174550 | - | responses differed between genotype groups | #4 |
- | neutral | plasma eicosanoid concentrations | TT homozygous subjects | r = 0.4-0.7 | correlated | #5 |
- | neutral | plasma eicosanoid concentrations | TT homozygous subjects | r = 0.4-0.7 | correlated | #6 |
- | no change | plasma eicosanoid concentrations | CC genotype | - | no correlations | #7 |
BACKGROUND: The health benefits of substituting dietary polyunsaturated fatty acids (PUFAs) for saturated fatty acids are well known. However, limited information exists on how the response to dietary intake of linoleic acid (LA; 18:2n-6) is modified by polymorphisms in the fatty acid desaturase (FADS) gene cluster. OBJECTIVES: The aim of the current study was to test the hypothesis that the FADS1 rs174550 genotype modifies the effect of dietary LA intake on the fatty acid composition of plasma lipids, fasting glucose, and high-sensitivity C-reactive protein (hsCRP). METHODS: Associations were investigated between genotype, plasma PUFAs, fasting glucose, and hsCRP concentrations in the cross-sectional, population-based Metabolic Syndrome in Men cohort (n = 1337). In addition, 62 healthy men from the cohort who were homozygotes for the TT or CC genotype of the FADS1 rs174550 were recruited to a 4-wk intervention (FADSDIET) with an LA-enriched diet. The fatty acid composition of plasma PUFAs and concentrations of plasma fasting glucose, serum hsCRP, and plasma lipid mediators (eicosanoids and related analogs) were measured at the beginning and end of the 4-wk intervention period. RESULTS: In the FADSDIET trial, the plasma LA proportion increased in both genotype groups in response to an LA-enriched diet. Responses in concentrations of serum hsCRP and plasma fasting glucose and the proportion of arachidonic acid (20:4n-6) in plasma phospholipids and cholesteryl esters differed between genotype groups (interaction of diet × genotype, P < 0.05). In TT homozygous subjects, plasma eicosanoid concentrations correlated with the arachidonic acid proportion in plasma and with hsCRP (r = 0.4-0.7, P < 0.05), whereas in the CC genotype there were no correlations. CONCLUSIONS: Our findings show that the FADS1 genotype modifies metabolic responses to dietary LA. The emerging concept that personalized dietary counseling should be modified by the FADS1 genotype needs to be tested in larger randomized trials. The study was registered at clinicaltrials.gov as NCT02543216.