Nut intake and 5-year changes in body weight and obesity risk in adults: results from the EPIC-PANACEA study.

PURPOSE: There is inconsistent evidence regarding the relationship between higher intake of nuts, being an energy-dense food, and weight gain. We investigated the relationship between nut intake and changes in weight over 5 years. METHODS: This study includes 373,293 men and women, 25-70 years old, recruited between 1992 and 2000 from 10 European countries in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Habitual intake of nuts including peanuts, together defined as nut intake, was estimated from country-specific validated dietary questionnaires. Body weight was measured at recruitment and self-reported 5 years later. The association between nut intake and body weight change was estimated using multilevel mixed linear regression models with center/country as random effect and nut intake and relevant confounders as fixed effects. The relative risk (RR) of becoming overweight or obese after 5 years was investigated using multivariate Poisson regressions stratified according to baseline body mass index (BMI). RESULTS: On average, study participants gained 2.1 kg (SD 5.0 kg) over 5 years. Compared to non-consumers, subjects in the highest quartile of nut intake had less weight gain over 5 years (-0.07 kg; 95% CI -0.12 to -0.02) (P trend = 0.025) and had 5% lower risk of becoming overweight (RR 0.95; 95% CI 0.92-0.98) or obese (RR 0.95; 95% CI 0.90-0.99) (both P trend <0.008). CONCLUSIONS: Higher intake of nuts is associated with reduced weight gain and a lower risk of becoming overweight or obese.

Main nutrient patterns are associated with prospective weight change in adults from 10 European countries.

PURPOSE: Various food patterns have been associated with weight change in adults, but it is unknown which combinations of nutrients may account for such observations. We investigated associations between main nutrient patterns and prospective weight change in adults. METHODS: This study includes 235,880 participants, 25-70 years old, recruited between 1992 and 2000 in 10 European countries. Intakes of 23 nutrients were estimated from country-specific validated dietary questionnaires using the harmonized EPIC Nutrient DataBase. Four nutrient patterns, explaining 67 % of the total variance of nutrient intakes, were previously identified from principal component analysis. Body weight was measured at recruitment and self-reported 5 years later. The relationship between nutrient patterns and annual weight change was examined separately for men and women using linear mixed models with random effect according to center controlling for confounders. RESULTS: Mean weight gain was 460 g/year (SD 950) and 420 g/year (SD 940) for men and women, respectively. The annual differences in weight gain per one SD increase in the pattern scores were as follows: principal component (PC) 1, characterized by nutrients from plant food sources, was inversely associated with weight gain in men (-22 g/year; 95 % CI -33 to -10) and women (-18 g/year; 95 % CI -26 to -11). In contrast, PC4, characterized by protein, vitamin B2, phosphorus, and calcium, was associated with a weight gain of +41 g/year (95 % CI +2 to +80) and +88 g/year (95 % CI +36 to +140) in men and women, respectively. Associations with PC2, a pattern driven by many micro-nutrients, and with PC3, a pattern driven by vitamin D, were less consistent and/or non-significant. CONCLUSIONS: We identified two main nutrient patterns that are associated with moderate but significant long-term differences in weight gain in adults.

Intake of ruminant trans-fatty acids, assessed by diet history interview, and changes in measured body size, shape and composition.

OBJECTIVE: Studies have suggested that total intake of trans-fatty acids (TFA) is positively associated with changes in body weight and waist circumference, whereas intake of TFA from ruminant dairy and meat products (R-TFA) has not been associated with weight gain. However, these previous studies are limited by self-reported measures of body weight and waist circumference or by a cross-sectional design. The objective of the present study was to investigate if R-TFA intake was associated with subsequent changes in anthropometry (body weight, waist and hip circumference) measured by technicians and body composition (body fat percentage). DESIGN: A 6-year follow-up study. Information on dietary intake was collected through diet history interviews, and anthropometric and bioelectrical impedance measurements were obtained by trained technicians at baseline (1987-1988) and at follow-up (1993-1994). Multiple regression with cubic spline modelling was used to analyse the data. SETTING: Copenhagen County, Denmark. SUBJECTS: Two hundred and sixty-seven men and women aged 35-65 years from the Danish MONICA (MONItoring of trends and determinants in CArdiovascular diseases) cohort. RESULTS: The median R-TFA intake was 1.3 g/d (5th, 95th percentile: 0.4, 2.7 g/d) or 0.6% of the total energy intake (5th, 95th percentile: 0.2, 1.1%). No significant associations were observed between R-TFA intake and changes in body weight, waist and hip circumference or body fat percentage. CONCLUSIONS: R-TFA intake within the range present in the Danish population was not significantly associated with subsequent changes in body size, shape or composition and the 95% confidence intervals indicate that any relevant associations are unlikely to have produced these observations.

Prediagnostic intake of dairy products and dietary calcium and colorectal cancer survival--results from the EPIC cohort study.

BACKGROUND: We investigated whether prediagnostic reported intake of dairy products and dietary calcium is associated with colorectal cancer survival. METHODS: Data from 3,859 subjects with colorectal cancer (42.1% male; mean age at diagnosis, 64.2 ± 8.1 years) in the European Investigation into Cancer and Nutrition cohort were analyzed. Intake of dairy products and dietary calcium was assessed at baseline (1992-2000) using validated, country-specific dietary questionnaires. Multivariable Cox regression models were used to calculate HR and corresponding 95% confidence intervals (CI) for colorectal cancer-specific death (n = 1,028) and all-cause death (n = 1,525) for different quartiles of intake. RESULTS: The consumption of total dairy products was not statistically significantly associated with risk of colorectal cancer-specific death (adjusted HR Q4 vs. Q1, 1.17; 95% CI, 0.97-1.43) nor that of all-cause death (Q4 vs. Q1, 1.16; 95% CI, 0.98-1.36). Multivariable-adjusted HRs for colorectal cancer-specific death (Q4 vs. Q1) were 1.21 (95% CI, 0.99-1.48) for milk, 1.09 (95% CI, 0.88-1.34) for yoghurt, and 0.93 (95% CI, 0.76-1.14) for cheese. The intake of dietary calcium was not associated with the risk of colorectal cancer-specific death (adjusted HR Q4 vs. Q1, 1.01; 95% CI, 0.81-1.26) nor that of all-cause death (Q4 vs. Q1, 1.01; 95% CI, 0.84-1.21). CONCLUSIONS: The prediagnostic reported intake of dairy products and dietary calcium is not associated with disease-specific or all-cause risk of death in patients diagnosed with colorectal cancer. IMPACT: The impact of diet on cancer survival is largely unknown. This study shows that despite its inverse association with colorectal cancer risk, the prediagnostic intake of dairy and dietary calcium does not affect colorectal cancer survival.

Adipose tissue trans-fatty acids and changes in body weight and waist circumference.

Previous studies have suggested that the intake of trans-fatty acids (TFA) plays a role in the development of obesity. The proportions of adipose tissue fatty acids not synthesised endogenously in humans, such as TFA, usually correlate well with the dietary intake. Hence, the use of these biomarkers may provide a more accurate measure of habitual TFA intake than that obtained with dietary questionnaires. The objective of the present study was to investigate the associations between the proportions of specific TFA in adipose tissue and subsequent changes in weight and waist circumference (WC). The relative content of fatty acids in adipose tissue biopsies from a random sample of 996 men and women aged 50-64 years drawn from a Danish cohort study was determined by GC. Baseline data on weight, WC and potential confounders were available together with information on weight and WC 5 years after enrolment. The exposure measures were total trans-octadecenoic acids (18:1t), 18:1 Δ6-10t, vaccenic acid (18:1 Δ11t) and rumenic acid (18:2 Δ9c, 11t). Data were analysed using multiple regression with cubic spline modelling. The median proportion of total adipose tissue 18:1t was 1.52% (90% central range 0.98, 2.19) in men and 1.47% (1.01, 2.19) in women. No significant associations were observed between the proportions of total 18:1t, 18:1 Δ6-10t, vaccenic acid or rumenic acid and changes in weight or WC. The present study suggests that the proportions of specific TFA in adipose tissue are not associated with subsequent changes in weight or WC within the exposure range observed in this population.

Synthesis, pharmacology, and biostructural characterization of novel α4ß2 nicotinic acetylcholine receptor agonists.

In our search for selective agonists for the α(4)ß(2) subtype of the nicotinic acetylcholine receptors (nAChRs), we have synthesized and characterized a series of novel heterocyclic analogues of 3-(dimethylamino)butyl dimethylcarbamate (DMABC, 4). All new heterocyclic analogues, especially N,N-dimethyl-4-(1-methyl-1H-imidazol-2-yloxy)butan-2-amine (7), showed an improved binding selectivity profile in favor of α(4)ß(2) over other nAChR subtypes, primarily due to impaired binding at ß(4) containing receptors. This observation can be rationalized based on cocrystal structures of (R)-4 and (R)-7 bound to acetylcholine binding protein from Lymnaea stagnalis. Functional characterization at both (α(4))(2)(ß(2))(3) and (α(4))(3)(ß(2))(2) receptors using two-electrode voltage clamp techniques in Xenopus laevis oocytes indicates that the investigated compounds interact differently with the two receptor stoichiometries. Compound 7 is an efficacious agonist at both α(4)-ß(2) and α(4)-α(4) binding sites, while the close analogue N,N-dimethyl-4-(1,4-dimethyl-1H-imidazol-2-yloxy)butan-2-amine (9) primarily activates via α(4)-ß(2) binding sites. The results suggest that it may be possible to rationally design compounds with specific stoichiometry preferences.

Carbamoylcholine analogs as nicotinic acetylcholine receptor agonists--structural modifications of 3-(dimethylamino)butyl dimethylcarbamate (DMABC).

Compounds based on the 3-(dimethylamino)butyl dimethylcarbamate (DMABC) scaffold were synthesized and pharmacologically characterized at the alpha(4)beta(2), alpha(3)beta(4,) alpha(4)beta(4) and alpha(7) neuronal nicotinic acetylcholine receptors (nAChRs). The carbamate functionality and a small hydrophobic substituent in the C-3 position were found to be vital for the binding affinity to the nAChRs, whereas the carbamate nitrogen substituents were important for nAChR subtype selectivity. Finally, the compounds were found to be agonists at the alpha(3)beta(4) nAChR.

Novel acetylcholine and carbamoylcholine analogues: development of a functionally selective alpha4beta2 nicotinic acetylcholine receptor agonist.

A series of carbamoylcholine and acetylcholine analogues were synthesized and characterized pharmacologically at neuronal nicotinic acetylcholine receptors (nAChRs). Several of the compounds displayed low nanomolar binding affinities to the alpha4beta2 nAChR and pronounced selectivity for this subtype over alpha3beta4, alpha4beta4, and alpha7 nAChRs. The high nAChR activity of carbamoylcholine analogue 5d was found to reside in its R-enantiomer, a characteristic most likely true for all other compounds in the series. Interestingly, the pronounced alpha4beta2 selectivities exhibited by some of the compounds in the binding assays translated into functional selectivity. Compound 5a was a fairly potent partial alpha4beta2 nAChR agonist with negligible activities at the alpha3beta4 and alpha7 subtypes, thus being one of the few truly functionally selective alpha4beta2 nAChR agonists published to date. Ligand-protein docking experiments using homology models of the amino-terminal domains of alpha4beta2 and alpha3beta4 nAChRs identified residues Val111(beta2)/Ile113(beta4), Phe119(beta2)/Gln121(beta4), and Thr155(alpha4)/Ser150(alpha3) as possible key determinants of the alpha4beta2/alpha3beta4-selectivity displayed by the analogues.

First total synthesis of (+/-)-3-hydroxy-11-norcytisine: structure confirmation and biological characterization.

The first total synthesis of the natural product 3-hydroxy-11-norcytisine (1), structurally related to cytisine (2), a benchmark ligand at neuronal nicotinic acetylcholine receptors (NNRs), has been achieved. The synthesis permits the unambiguous confirmation of the structure originally proposed for 1 and has enabled initial biological characterization of 1 and its related compounds against NNRs.

5-Substituted imidazole-4-acetic acid analogues: synthesis, modeling, and pharmacological characterization of a series of novel gamma-aminobutyric acid(C) receptor agonists.

A series of ring-substituted analogues of imidazole-4-acetic acid (IAA, 4), a partial agonist at both GABAA and GABAC receptors (GABA = gamma-aminobutyric acid), have been synthesized. The synthesized compounds 8a-l have been evaluated as ligands for the alpha1beta2gamma2S GABAA receptors and the rho1 GABAC receptors using the FLIPR membrane potential (FMP) assay and by electrophysiology techniques. None of the tested compounds displayed activity at the GABAA receptors at concentrations up to 1000 microM. However, the 5-Me, 5-Ph, 5-p-Me-Ph, and 5-p-F-Ph IAA analogues, 8a,c,f,g, displayed full agonist activities at the rho1 receptors in the FMP assay (EC50 in the range 22-420 microM). Ligand-protein docking identified the Thr129 in the alpha1 subunit and the corresponding Ser168 residue in rho1 as determinants of the selectivity displayed by the 5-substituted IAA analogues. The fact that GABA, 4, and 8a displayed decreased agonist potencies at a rho1Ser168Thr mutant compared to the WT rho1 receptor strongly supported this hypothesis. However, in contrast to GABA and 4, which exhibited increased agonist potencies at a alpha1(Thr129Ser)beta2gamma2 mutant compared to WT GABAA receptor, the data obtained for 8a at the WT and mutant receptors were nonconclusive.