Consumption of whole grain reduces risk of deteriorating glucose tolerance, including progression to prediabetes
ABSTRACT BACKGROUND: High whole-grain intake has been reportedly associated with reduced risk of developing type 2 diabetes (T2D), which is an effect possibly subject to genetic effect modification. Confirmation in prospective studies and investigations on the impact on prediabetes is needed. OBJECTIVES: In a prospective population-based study, we investigated whether a higher intake of whole grain protects against the development of prediabetes and T2D and tested for modulation by polymorphisms of the TCF7L2 gene. DESIGN: We examined the 8-10-y incidence of prediabetes (impaired glucose tolerance, impaired fasting glucose, or the combination of both) and T2D in relation to the intake of whole grain. Baseline data were available for 3180 women and 2297 men aged 35-56 y. RESULTS: A higher intake of whole grain (>59.1 compared with <30.6 g/d) was associated with a 34% lower risk to deteriorate in glucose tolerance (to prediabetes or T2D; women and men combined). The association remained after adjustments for age, family history of diabetes, BMI, physical activity, smoking, education, and blood pressure (OR: 0.78; 95% CI: 0.63, 0.96). Risk reduction was significant in men (OR: 0.65; 95% CI: 0.49, 0.85) but not in women. Associations were significant for prediabetes per se (all, OR: 0.73; 95% CI: 0.56, 0.94; men, OR: 0.57; 95% CI: 0.40, 0.80). The intake of whole grain correlated inversely with insulin resistance (HOMA-IR). The impact of whole-grain intake was undetectable in men who harbored diabetogenic polymorphisms of the TCF7L2 gene. CONCLUSIONS: A higher intake of whole grain is associated with decreased risk of deteriorating glucose tolerance including progression from normal glucose tolerance to prediabetes by mechanisms likely tied to effects on insulin sensitivity. Effect modifications by TCF7L2 genetic polymorphisms are supported.
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ABSTRACT: Previously, a healthy Nordic diet (ND) has been shown to have beneficial health effects close to those of Mediterranean diets. The objective was to explore whether the ND has an impact on gene expression in abdominal subcutaneous adipose tissue (SAT) and whether changes in gene expression are associated with clinical and biochemical effects. Obese adults with features of the metabolic syndrome underwent an 18- to 24-wk randomized intervention study comparing the ND with the control diet (CD) (the SYSDIET study, carried out within Nordic Centre of Excellence of the Systems Biology in Controlled Dietary Interventions and Cohort Studies). The present study included participants from 3 Nordic SYSDIET centers [Kuopio (n = 20), Lund (n = 18), and Oulu (n = 18)] with a maximum weight change of ±4 kg, highly sensitive C-reactive protein concentration <10 mg/L at the beginning and the end of the intervention, and baseline body mass index (in kg/m(2)) <38. SAT biopsy specimens were obtained before and after the intervention and subjected to global transcriptome analysis with Gene 1.1 ST Arrays (Affymetrix). Altogether, 128 genes were differentially expressed in SAT between the ND and CD (nominal P < 0.01; false discovery rate, 25%). These genes were overrepresented in pathways related to immune response (adjusted P = 0.0076), resulting mainly from slightly decreased expression in the ND and increased expression in the CD. Immune-related pathways included leukocyte trafficking and macrophage recruitment (e.g., interferon regulatory factor 1, CD97), adaptive immune response (interleukin32, interleukin 6 receptor), and reactive oxygen species (neutrophil cytosolic factor 1). Interestingly, the regulatory region of the 128 genes was overrepresented for binding sites for the nuclear transcription factor κB. A healthy Nordic diet reduces inflammatory gene expression in SAT compared with a control diet independently of body weight change in individuals with features of the metabolic syndrome. The study was registered at clinicaltrials.gov as NCT00992641. © 2015 American Society for Nutrition.American Journal of Clinical Nutrition 01/2015; 101(1):228-39. DOI:10.3945/ajcn.114.092783 · 6.92 Impact Factor
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ABSTRACT: Type 2 diabetes (T2D) is thought to arise from an interaction between susceptibility genes and a diabetogenic environment. This review summarizes progress pertaining specifically to gene-diet interactions. Recent efforts have been population-based and have focused on established genetic and dietary risk factors for T2D. TCF7L2 × carbohydrate-quality and IRS1 × macronutrient-composition interactions are promising factors, but most studies of gene-diet interactions are conflicting or need follow-up. T2D genetic risk scores are powerful predictors of developing T2D, but whether they can be combined with dietary risk factors merits further study. Lack of statistical power, imprecise diet measures, and conceptual issues surrounding replication all challenge our efforts to characterize interactions. Collaborations are needed for optimal study designs in both hypothesis-testing and hypothesis-generating contexts. Continued investment in studies of gene-diet interactions may lead to novel mechanistic insights into T2D, opportunities for risk stratification, and ultimately to personalized nutrition to prevent the disease.12/2014; 3(4). DOI:10.1007/s13668-014-0095-1
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ABSTRACT: There is evidence that dietary habits contribute to the presence and severity of non-alcoholic fatty liver disease (NAFLD). The aim of the present study was to explore any associations between consumption of grains and the development and severity of NAFLD. Seventy-three consecutive NAFLD patients were enrolled. Additionally, 58 controls matched for age, sex and body mass index with 58 patients were also included. Consumption of grains was estimated through a semi-quantitative food frequency questionnaire. Medical history, anthropometric indices, body composition analysis, physical activity data, biochemical and inflammatory markers were available for all the participants. Liver stiffness measurement by transient elastography was performed in 58 and liver biopsy in 34 patients. In patients, consumption of whole grains was associated with lower abdominal fat level (β = -0.24, p = 0.02) and lower levels of insulin resistance index (β = -0.28, p = 0.009), while it also correlated inversely with interleukin-6 levels (ρ = -0.23, p = 0.05). Consumption of whole grains was associated with lower likelihood of having histological steatohepatitis (OR 0.97, 95 % CI 0.94-1.000), after adjusting for sex and energy intake, but the association became weaker after further adjusting for abdominal fat or interleukin-6 levels. In the case-control analysis, consumption of refined grains was associated with higher odds of having NAFLD (OR 1.021, 95 % CI 1.001-1.042), after adjusting for age, sex, energy intake, abdominal fat level, HOMA-IR, LDL, adiponectin and TNF-α. Although refined grain consumption increased the likelihood of having NAFLD, whole-grain consumption favorably affected clinical characteristics of patients with NAFLD and tended to be associated with less severe disease.European Journal of Nutrition 03/2014; 53(8). DOI:10.1007/s00394-014-0679-y · 3.84 Impact Factor