Dietary intake of polychlorinated dibenzo-p-dioxins and furans, adiposity and obesity status

Association between dietary intake estimated levels of PCDD/Fs and human sperm quality

This study aimed to investigate the association between estimated dietary intake of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and human sperm quality. This study cross-sectionally assessed the associations between estimated dietary intake of PCDD/Fs and sperm quality parameters in 200 participants aged 18-40 years from the Led-Fertyl study. Linear regression models, accounting for potential confounding variables, were employed to evaluate the relationships. To estimate the PCDD/Fs exposure, food frequency questionnaires and the latest data on PCDD/Fs concentrations in food, primarily from Spanish sources, were used. Our findings indicate that, in comparison to participants in the lowest tertile, those in the highest tertile (T3) of PCDD/Fs dietary intake exhibited significantly elevated body mass index, increased consumption of meat, fish and eggs, and decreased consumption of nuts. Furthermore, individuals in T3 demonstrated a higher percentage of sperm head abnormalities (4.65 % [0.10; 9.24]; p-trend= 0.037) and a corresponding increase per 1-SD increment in energy-adjusted total PCDD/Fs dietary intake (1.84 % [0.38; 3.68]). No significant associations for other sperm parameters were found. Minimal research exists on PCDD/F dietary exposure and human sperm quality. This study shows significant direct association between higher PCDD/Fs intake and the percentage of sperm head abnormalities which potentially may compromise human reproductive health.

Evidence of a positive association between dietary exposure to polychlorinated biphenyl (PCB) and weight gain among women in the E3N prospective cohort

BACKGROUND

Polychlorinated biphenyls (PCB) and dioxins are persistent organic pollutants found in food and known for their ability to bioaccumulate. Various animal studies have highlighted obesogenic effects related to the exposure to PCB and dioxins, nevertheless human studies have led to inconsistent results. The present study aims to investigate the associations between dietary intakes of PCB and dioxins and the risk of weight gain, overweight and obesity in the French E3N cohort (Étude Épidémiologique auprès de femmes de la mutuelle générale de l'Éducation Nationale).

METHODS

The present study included 63,758 women with a mean age of 52.9 years, who completed a food frequency questionnaire in 1993 and were followed for 23 years. Dietary intakes to the sum of dioxins and dioxin-like PCB (DL-PCB) and to non-dioxin-like PCB (NDL-PCB) were estimated using food consumption data combined with food contamination levels from the French Agency for Food, Environmental and Occupational Health and Safety (ANSES). Adjusted Cox proportional hazard models were used to estimate hazard ratios (HR) and their 95 % confidence intervals for the risk of obesity, overweight and weight gain >10 kg during follow-up.

RESULTS

Our results suggest a positive and linear association between dietary intakes of dioxins + DL-PCB and intakes of NDL-PCB and the risk of weight gain (HRdioxins+DL-PCB = 1.07 (1.05-1.1), HRNDL-PCB = 1.08 (1.06-1.1)), overweight (HRdioxins+DL-PCB = 1.03 (1.01-1.05), HRNDL-PCB = 1.05 (1.03-1.06)), and obesity (HRdioxins+DL-PCB = 1.08 (1.04-1.12), HRNDL-PCB = 1.09 (1.06-1.12)). In sensitivity analyses adjusting for diet, the association between dioxins + DL-PCB dietary intake and obesity was no longer observed. Results remained unchanged or were attenuated but still significant regarding the association between dietary intake of NDL-PCB and obesity risk in all sensitivity analyses. Similar results were observed for the risks of weight gain and overweight.

DISCUSSION

This study suggests a positive and linear association between dietary intakes of NDL-PCB and the risk of obesity, a major risk factor for most non communicable diseases. Further studies are needed to confirm these results in other populations and to better understand the biological mechanisms underlying this association.

Serum metabolism distribution in individuals exposed to dioxins: A case study of residents near the municipal solid waste incinerators in China

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) have attracted considerable attention owing to their environmental persistence, bioaccumulation, and high toxicity. This study aimed to investigate changes in serum metabolites following exposure to PCDD/Fs and to reveal a novel pathogenesis of PCDD/Fs. Serum samples were collected from 75 residents living near a municipal solid waste incinerator in China to analyse the relationship between PCDD/Fs and serum metabolic components. The serum level in the low-exposure group [19.07 (13.44-23.89) pg-TEQ/L] was significantly lower than that in the high-exposure group [115.60 (52.28-592.65) pg-TEQ/L]. Non-targeted metabolomic studies based on liquid chromatography-high resolution mass spectrometry have been applied to the metabolomic analysis of serum. Thirty-seven metabolites with significant differences among the different groups were identified as biomarkers. Pathway analysis revealed that high dioxin exposure perturbed various biological processes, including glycerol phospholipid metabolism and the interconversion of pentose and glucuronate. The results of a population health survey showed that the serum dioxin concentration in patients with diabetes was significantly higher than that in the control population. These findings suggest that dioxin exposure is associated with several potential adverse health risks, including inflammation, diabetes, and cardiovascular disease, through metabolic changes.

Dioxins and furans maternal transfer: A study of breast milk and cord serum levels among Lebanese mothers and associations with newborn anthropometric measurements

Dioxins and furans (PCDD/Fs) are anthropogenic pollutants that persist in the environment for long years, bioaccumulating in food & contaminating humans. In pregnancy, they can transfer through the placenta and reach the fetus, which negatively affects fetal growth. They can also reach newborns through breastfeeding. In this study, we focused on this critical subpopulation and identified the presence of PCDD/Fs among pregnant women in breast milk (n = 41) and cord serum (n = 49); we assessed the correlation between different matrices, evaluated the predictors and associations with newborn anthropometric measurements. Over 70.7 % of PCDD/Fs were detected in breast milk and 46.9-55.1 % in cord serum. Cord/maternal serum and breast milk to maternal serum ratios were > 1 with a significant positive Spearman correlation (0.669-0.729). Breast milk & maternal serum PCDD/Fs were associated inversely with age and positively with red meat intake. Cord serum PCDD/Fs were inversely associated with pre-pregnancy weight loss and passive smoking. Parity and gestational weight gain showed positive associations with Z-scores at birth. Z-score differences showed negative and positive associations with passive smoking and pre-pregnancy BMI respectively.