Comparison of a Mediterranean to a low-fat diet intervention in adults with type 1 diabetes and metabolic syndrome: A 6-month randomized trial.

BACKGROUND AND AIMS: The metabolic syndrome (MS) is an emerging complication in patients with type 1 diabetes (T1D), with no preventive or therapeutic treatment reported yet. We wanted to compare the impact of two 6-month nutritional interventions, based on a Mediterranean (MED) or a low-fat diet, on waist circumference, anthropometric and metabolic outcomes in patients with both T1D and the MS. METHODS AND RESULTS: Participants were randomized into 2 intervention groups: 1) MED-diet or 2) low-fat diet. The 6-month study included 9 teaching sessions with a registered dietitian. Anthropometric (primary outcome: waist circumference), metabolic and nutritional assessments were performed at inclusion, 3 and 6-month. We used mixed effects models to assess the effects of both interventions. 28 participants were included (50.9 ± 10.3 years old) with a mean BMI of 30.7 ± 3.3 kg/m2 and a waist circumference of 105.5 ± 8.9 cm at inclusion. A trend towards a greater reduction of dietary fat intakes in the low-fat diet group was observed (P-interaction = 0.09). Waist circumference was reduced at 6-month in both groups (-3.5 cm low-fat; -1.5 cm MED-diet) with no significant difference between groups (P-interaction = 0.43). Body mass index also significantly decreased in both groups (-0.7 kg/m2 low-fat; -1.1 kg/m2 MED-diet; P-interaction = 0.56). No significant differences between groups were observed for other metabolic parameters. CONCLUSIONS: This study suggests that a 6-month non-restrictive dietary intervention in patients with T1D and MS could contribute to weight management, without significant differences between interventions for anthropometric and metabolic parameters. Further studies should investigate the long-term benefits of these diets. CLINICAL TRIAL REGISTRY: NCT02821585 (https://clinicaltrials.gov/).

Validation of the omega-3 fatty acid intake measured by a web-based food frequency questionnaire against omega-3 fatty acids in red blood cells in men with prostate cancer.

BACKGROUND/OBJECTIVES: The objective of this study was to evaluate the ability of a web-based self-administered food frequency questionnaire (web-FFQ) to assess the omega-3 (ω-3) fatty acids (FAs) intake of men affected with prostate cancer (PCa) against a biomarker. SUBJECTS/METHODS: The study presented herein is a sub-study from a phase II clinical trial. Enrolled patients afflicted with PCa were included in the sub-study analysis if the FA profiles from the red blood cell (RBC) membranes and FA intakes at baseline were both determined at the time of the data analysis (n=60). Spearman's correlation coefficients were calculated to estimate the correlations between FA intakes and their proportions in the RBC membranes. RESULTS: Intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were highly correlated with their respective proportions in the RBC membranes (both rs=0.593, P<0.0001). Correlation between alpha-linolenic acid (ALA) intake and its proportion in RBC was not significant (rs=0.130, P=0.332). Correlations were observed between fatty fish intake and total ω-3 FAs (rs=0.304, P=0.02), total long-chain ω-3 FAs (rs=0.290, P=0.03) and DHA (rs=0.328, P=0.01) in RBC membranes. CONCLUSIONS: This study has shown that the web-FFQ is an accurate tool to assess total long-chain ω-3 FAs, EPA and DHA but not ALA intake in clinical trials and epidemiological studies carried out in men with PCa.

Quality of diet is associated with insulin resistance in the Cree (Eeyouch) indigenous population of northern Québec.

BACKGROUND AND AIMS: Indigenous people worldwide have a greater disease burden than their non-aboriginal counterparts with health challenges that include increased obesity and higher prevalence of diabetes. We investigate the relationships of dietary patterns with nutritional biomarkers, selected environmental contaminants and measures of insulin resistance in the Cree (Eeyouch) of northern Québec Canada. METHODS AND RESULTS: The cross-sectional 'Nituuchischaayihitaau Aschii: A Multi-Community Environment-and-Health Study in Eeyou Istchee' recruited 835 adult participants (≥18 y) from 7 communities in the James Bay region of northern Québec. The three dietary patterns identified by principal component analysis (PCA) were: inland and coastal patterns with loadings on traditional foods, and a junk food pattern with high-fat and high-sugar foods. We investigated dietary patterns scores (in quantiles) in relation with nutritional biomarkers, environmental contaminants, anthropometry, blood pressure, fasting plasma glucose and insulin, and insulin resistance. Homeostatic model assessment (HOMA-IR) was used as surrogate markers of insulin resistance. ANCOVA ascertained relationships between dietary patterns relationship and outcomes. Greater scores for the traditional patterns were associated with higher levels of n-3 fatty acids, mercury and polychlorinated biphenyls (PCBs) (P trend <0.001). Higher scores for the junk food pattern were associated with lower levels of PCBs and Vitamin D, but higher fasting plasma insulin and HOMA-IR. CONCLUSION: Our results suggest that poor diet quality accompanied greater insulin resistance. Impacts of diet quality on insulin resistance, as a sign of metabolism perturbation, deserve more attention in this indigenous population with high rates of obesity and diabetes.

Docosahexaenoic acid-enriched canola oil increases adiponectin concentrations: a randomized crossover controlled intervention trial.

BACKGROUND AND AIMS: Little is known about the effect of various dietary fatty acids on pro- and anti-inflammatory processes. We investigated the effect of 5 oils containing various amounts of alpha-linolenic acid (ALA), linoleic acid (LA), oleic acid (OA) and docosahexaenoic acid (DHA) on plasma inflammatory biomarkers and expression levels of key inflammatory genes and transcription factors in whole blood cells. METHODS AND RESULTS: In a randomized, crossover controlled nutrition intervention, 114 adult men and women with abdominal obesity and at least one other criterion for the metabolic syndrome consumed 5 experimental isoenergetic diets for 4 weeks each, separated by 4-week washout periods. Each diet provided 60 g/3000 kcal of different oils: 1) control corn/safflower oil blend (CornSaff; LA-rich), 2) flax/safflower oil blend (FlaxSaff; ALA-rich), 3) conventional canola oil (Canola; OA-rich), 4) high oleic canola oil (CanolaOleic; highest OA content), 5) DHA-enriched high oleic canola oil (CanolaDHA; OA- and DHA-rich). Gene expression in whole blood cells was assessed in a subset of 62 subjects. CanolaDHA increased plasma adiponectin concentrations compared with the control CornSaff oil treatment (+4.5%, P = 0.04) and FlaxSaff (+6.9%, P = 0.0008). CanolaDHA also reduced relative expression levels of interleukin (IL)1B compared with CornSaff and Canola (-11% and -13%, respectively, both P = 0.03). High-sensitivity C-reactive protein concentrations were lower after Canola than after FlaxSaff (-17.8%, P = 0.047). CONCLUSION: DHA-enriched canola oil exerts anti-inflammatory effects compared with polyunsaturated fatty acids from plant sources.

Association of red blood cell n-3 polyunsaturated fatty acids with plasma inflammatory biomarkers among the Quebec Cree population.

BACKGROUND/OBJECTIVES: We examined the prevalence of elevated plasma high-sensitivity C-reactive protein (hs-CRP) concentrations and associations with red blood cell (RBC) long-chain n-3 polyunsaturated fatty acids (LCn-3PUFA) in the James Bay Cree population from the province of Quebec (Canada). SUBJECTS/METHODS: A total of 744 Cree adults (18-91 years) from seven communities of Eastern James Bay were included in these cross-sectional analyses. Associations between RBC LCn-3PUFA and proinflammatory markers (hs-CRP, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α)) were assessed by using multivariate general linear models with adjustment for sex, age and waist circumference. An arbitrary inflammation score was defined based on the sum of the quartiles of hs-CRP, IL-6 and TNF-α concentrations (range=3-12). RESULTS: Elevated hs-CRP concentrations (>3 mg/l) were present in 46.9% (95% confidence interval (CI) 43.3-50.5) of the James Bay Cree population. RBC docosapentaenoic acid (DPAn-3; C22:5n-3) was inversely associated with hs-CRP, TNF-α and the inflammation score (all P trend<0.02), whereas eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3) in RBC were not associated with inflammation (all P trend>0.18). Among participants with RBC DPAn-3 levels above the median of the population, odds ratio of having an elevated inflammation score (≥9) was 0.67 (95% CI, 0.48-0.93) compared with participants below the median. CONCLUSIONS: RESULTS indicate that low-grade systemic inflammation is highly prevalent and that higher RBC DPAn-3 levels are associated with a lower risk of systemic inflammation in the James Bay Cree population.

Validity and reproducibility of a web-based, self-administered food frequency questionnaire.

BACKGROUND/OBJECTIVES: To assess the validity and the reproducibility of a newly developed web-based, self-administered food frequency questionnaire (web-FFQ). SUBJECTS/METHODS: A total of 74 healthy subjects (34 men and 40 women) from the Québec City metropolitan area were asked to complete, in random order, the web-FFQ, a validated interviewer-administered FFQ (IA-FFQ) and a 3-day food record (3-day FR). RESULTS: Mean intakes of 17/22 nutrients assessed between the web-FFQ and the 3-day FR were not significantly different (differences <10%, P≥0.11). Sex and energy-adjusted de-attenuated Pearson correlation coefficients for each nutrient varied from 0.12-0.98 (mean R=0.55, 95% confidence interval 0.46; 0.63) between the web-FFQ and the 3-day FR. All correlations were significant (P≤0.01) and above 0.34 (mean R=0.59, 95% confidence interval 0.54; 0.65) between the web-FFQ and the IA-FFQ, except for sodium (R=0.17, P=0.14). Cross-classification analysis revealed that on average, 77% of subjects were classified in the same or adjacent quartile of nutrient intake between the web-FFQ and the 3-day FR. Correlation coefficients for reproducibility of the web-FFQ tested 4-6 weeks apart in the same individuals were all equal or above 0.48 (P≤0.0001; mean R=0.72, 95% confidence interval 0.68; 0.76). More than 90% of the subjects were classified in the same or adjacent quartile between the two administrations of the web-FFQ, while only 0.8% was misclassified. CONCLUSIONS: These data demonstrate that the newly developed web-based FFQ appears to have reasonable validity and good reproducibility for assessing nutrient intakes at the group and individual levels in a population of healthy adults.