| Objective: Polymorphisms of the fatty acid desaturase (FADS) gene cluster have been associated with obesity and
its-related consequences. This cross-sectional study aimed to investigate whether the adherence to dietary nonenzymatic
antioxidant capacity (NEAC), reflecting the antioxidant potential of the whole diet, modifies the association
of FADS2 rs174583 polymorphism with cardio-metabolic risk factors in obese adults.
Methods: The present study included 347 healthy obese adults (aged 20–50 years). Dietary NEAC was assessed by
a validated food frequency questionnaire with 147 items and estimated through total radical-trapping antioxidant
parameters (TRAP), oxygen radical absorbance capacity (ORAC), and ferric reducing ability of plasma (FRAP) with the
use of published databases. FADS2 rs174583 polymorphism was characterized using PCR–RFLP. ANCOVA multivariate
interaction model was used to analyze gene-diet interactions.
Results: after adjustment for the confounding variables (age, physical activity, SES and WC), this study showed
significant interactions between rs174583 polymorphism and adherence to dietary ORAC on the serum cholesterol (P
Interaction = 0.029), LDL-C (P Interaction = 0.025) and HDL-C levels (P Interaction = 0.049) among the male group; minor allele
carriers who had the highest adherence to the NEAC (ORAC) showed a better metabolic profile (lower TG and LDL-C
and higher HDL-C) (P < 0.05). Among women, the dietary ORAC-rs174583 interactions were statistically significant for
the serum insulin concentration (P Interaction = 0.020), QUICKI (P Interaction = 0.023) and HOMA-IR (P Interaction = 0.017); the
highest QUICKI and the lowest HOMA-IR and serum insulin levels were observed in the CC homozygote carriers with
the moderate compliance with the dietary ORAC (P < 0.05). In addition, the dietary TRAP modified the association
between FADS2 variant and change in LDL-C levels (P Interaction = 0.037); the homozygous wild-type (CC) women who
placed in the top tertile of TRAP had significantly the lowest LDL-C levels than those in the second tertile (P < 0.05).
Conclusion: These data indicate that the FADS2 rs174583 polymorphism interacts with the dietary NEAC to influence
cardio-metabolic risk factors in obese subjects. Replication in prospective cohort studies among other populations is
required to confirm the results of our study |