Interplay between fatty acid desaturase2 (FADS2) rs174583 genetic variant and dietary antioxidant capacity: cardio-metabolic risk factors in obese individuals.

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 non-enzymatic 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.

Dietary total antioxidant capacity interacts with a variant of chromosome 5q13-14 locus to influence cardio-metabolic risk factors among obese adults.

Background: The association between cocaine- and amphetamine-regulated transcript prepropeptide gene (CARTPT) and obesity-related outcomes has shown in the epidemiological studies. Nevertheless, there is lack of data regarding the CARTPT gene-diet interactions in terms of antioxidant potential of diet. So, this study aimed to test CARTPT gene-dietary non-enzymatic antioxidant capacity (NEAC) interactions on cardio-metabolic risk factors in obese individuals. Methods and material: The present cross-sectional study was carried out among 288 apparently healthy obese adults within age range of 20-50 years. Antioxidant capacity of diet was estimated by calculating the oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), total radical-trapping antioxidant parameter (TRAP) and Trolox equivalent antioxidant capacity (TEAC) using a semiquantitative food frequency questionnaire (FFQ). Genotyping for CARTPT rs2239670 polymorphism was conducted by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: A significant interaction was revealed between CARTPT rs2239670 and dietary ORAC on BMI (PInteraction = 0.048) and fat mass percent (FM%) (PInteraction = 0.008); in A allele carriers, higher adherence to the dietary ORAC was related to lower level of BMI and FM%. And, the significant interactions were observed between FRAP index and rs2239670 in relation to HOMA (PInteraction = 0.049) and QUICKI (PInteraction = 0.048). Moreover, there were significant interactions of rs2239670 with TRAP (PInteraction = 0.029) and TEAC (PInteraction = 0.034) on the serum glucose level; individuals with AG genotype were more respondent to higher intake of TRAP. Conclusion: The present study indicated that the relationships between CARTPT rs2239670 and obesity and its-related metabolic parameters depend on adherence to the dietary NEAC. Large prospective studies are needed to confirm our findings.

Effects of soy intake on circulating levels of TNF-α and interleukin-6: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: Pro-inflammatory mediators, including serum tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), can be used as biomarkers to indicate or monitor disease. This study was designed to ascertain the effects of soy products on TNF-α and IL-6 levels. METHODS: PubMed, EMBASE, Science Direct, Web of Science, Google Scholar and the Cochrane Central Register of Controlled Trials were searched to November 2019 for RCTs around the effects of soy-based products on TNF-α and IL-6. A random effects model was used to calculate overall effect size. RESULTS: In total, 29 eligible publications were considered in the present systematic review, of which 25 were included in this meta-analysis. The overall effect of soy products on TNF-α and IL-6 levels failed to reach statistical significance (MD = - 0.07; 95% CI - 0.22-0.09; I2 50.9; MD = 0.03; 95% CI - 0.07-0.14; I2 42.1, respectively). According to a subgroup analysis, natural soy products led to a reduction in TNF-α concentration compared with processed soy products (MD = - 0.32; 95% CI - 0.45 to - 0.19; I2 0.0). Moreover, IL-6 reduction was stronger in participants who were affected by different diseases (MD = - 0.04; 95% CI - 0.07 to - 0.02; I2 0.0). CONCLUSIONS: A review of RCTs published to November 2019 found that natural soy products are effective in lowering TNF-α levels. While the beneficial effects on reduction of IL-6 appeared stronger in individuals affected by different diseases, this finding cannot be generalized to all individuals affected by different diseases.

The association between different kinds of fat intake and breast cancer risk in women.

So far several animal and case-control studies have confirmed this hypothesis that dietary fat increases the risk of breast cancer. However, cohort studies have not shown this relationship. The aim of this study was to review the studies on the relationship between dietary fat intake and breast cancer risk among women. Electronic database PubMed and Google Scholar were searched using the key words: Breast cancer, dietary fat, serum estrogen, saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). The evidence of the studies regarding to the association of total and subtypes of fat intake with breast cancer risk are inconsistent. Several studies have shown that, among several types of fat, SFAs and w-3 PUFA intake are associated with an increased and reduced risk of breast cancer, respectively. The relationship between MUFAs intake and breast cancer risk is conflicting. Narrow ranges of fat intake among populations, measurement errors, high correlation between specific types of dietary fat, the confounding variables like body fatness and high-energy intake and other dietary components such as fiber and antioxidants might be probable explanations for these inconsistent results. Although we are not at a stage where we can justifiably advise women to reduce their fat intake to decrease the risk of developing breast cancer, it seems the current guidelines to lower total fat consumption and recommendation to consumption of unsaturated fats such as MUFAs and w-3 fatty acids and also reduction of SFAs (meat and dairy products) intake to avoid heart disease is also useful for breast cancer risk.