Karen E. Assmann

Determinants of vitamin D status in Caucasian adults: influence of sun exposure, dietary intake, sociodemographic, lifestyle, anthropometric, and genetic factors.

Very few studies have investigated the determinants of serum vitamin D levels using a set of variables that include simultaneously sun exposure, phototype, dietary intake, sociodemographics, anthropometric, lifestyle data, and genetic polymorphisms. Our objective was to investigate the associations between all these parameters and vitamin D status in a large sample of French adults. This cross-sectional survey was based on 1,828 middle-aged Caucasian adults from the SU.VI.MAX (SUpplémentation en VItamines et Minéraux AntioXydants) study. Plasma 25-hydroxyvitamin D (25OHD) concentration was lower among women (P<0.0001), older subjects (P=0.04), obese/underweight (P<0.0001), those living at higher latitudes (P<0.0001), those whose blood draw occurred in early spring (P<0.0001), less physically active (P<0.0001), with low sun exposure (P<0.0001), and with no-to-low alcohol intake (P=0.0001). Mutant GC rs4588 and rs7041 single nucleotide polymorphisms were associated with lower and higher 25OHD concentrations, respectively (P<0.0001). Dietary intake was not a major determinant of vitamin D status (P=0.7). This study provides an overall picture of determinants of vitamin D status. Several modifiable factors were identified, such as daily-life moderate sun exposure, physical activity, and normal-weight maintenance, which should be targeted by public health policies in order to improve vitamin D status in the general population, while avoiding active/intensive sun exposure, in line with recommendations for skin cancer prevention.

Prospective association between the dietary inflammatory index and metabolic syndrome: Findings from the SU.VI.MAX study

BACKGROUND AND AIMS The prevention of the metabolic syndrome (MetS) is of major concern and nutrition has been shown to modulate at least partly MetS risk. Our objective was to investigate whether a pro-inflammatory diet was associated with a higher risk of MetS and its components in a large cohort of French adults. METHODS AND RESULTS A total of 3726 participants from the Supplémentation en Vitamines et Minéraux AntioXydants (SU.VI.MAX) cohort were included in this study. The MetS status was identified at baseline and after 13 years of follow-up using self-reported medication, data from clinical investigations and biological measurements. The dietary inflammatory index (DII) was computed using repeated 24 h-dietary records (n = 10.1 ± 3.1). Logistic and linear regression analyses were conducted to assess the prospective association of the DII (as Q, quartiles) with the incidence of MetS and with the traits contributing to the MetS-definition (blood pressure, glycaemia, triglycerides, HDL-cholesterol, waist circumference). A diet with pro-inflammatory properties, as expressed by higher DII scores, was significantly associated with a higher risk of developing the MetS (OR comparing Q4 to Q1: 1.39, 95% confidence interval 1.01-1.92, P = 0.047). Moreover, higher DII scores were associated with higher systolic and diastolic blood pressure (Ptrend across quartiles = 0.03 and 0.05, respectively) and triglycerides (Ptrend = 0.01), and with lower HDL-cholesterol (Ptrend = 0.03). CONCLUSION A higher DII score was prospectively associated with a higher risk of MetS, with associations with blood pressure, triglycerides and HDL-cholesterol. Promotion of a healthy diet exhibiting anti-inflammatory properties may contribute to prevent cardio-metabolic disorders.

Prospective Association Between the Dietary Inflammatory Index and Cardiovascular Diseases in the SUpplémentation en VItamines et Minéraux AntioXydants (SU.VI.MAX) Cohort

Background Cardiovascular diseases (CVD) are the leading cause of death in the world, and diet plays a major role in CVD incidence, especially through lipid oxidation mechanisms. This, in turn, leads to tissue inflammation and formation of atheromatous plaques. Methods and Results Our objective was to evaluate the association between the inflammatory potential of the diet and the incidence of overall CVD or its subclasses. We included 7743 participants from the Supplémentation en Vitamines et Minéraux AntioXydants (SU.VI.MAX) cohort. All cardiovascular events were recorded using self‐reported information or clinical visits, and were validated. The dietary inflammatory index (DII) was computed using repeated 24‐hour dietary records (mean=9.5±3.4 records/subject). Hazard ratio and 95% CI for outcomes (CVD and subclasses) were estimated across sex‐specific quartiles of the DII using Cox proportional hazard models. A total of 292 cardiovascular events were recorded and validated during an average of 11.4 years of follow‐up: 93 myocardial infarctions, 58 strokes, 128 angina pectoris and revascularization interventions, and 13 sudden deaths. When considering CVD subclasses, a diet with pro‐inflammatory properties, as expressed by higher DII scores, was significantly associated with a higher risk of myocardial infarction (hazard ratioQuartile 4 versus Quartile 1=2.24, 95% CI: 1.08–4.67). No significant association was observed between the DII score and stroke or both angina pectoris and revascularization intervention. Conclusions A pro‐inflammatory diet, as measured by a higher DII score, was prospectively associated with a higher risk of myocardial infarction. Promotion of a diet exhibiting anti‐inflammatory properties may help prevent myocardial infarctions.

Prospective association of protein intake during puberty with body composition in young adulthood

To examine the association of habitual animal and plant protein intake during the potentially critical period of puberty with body composition in young adulthood.

Healthy Aging 5 Years After a Period of Daily Supplementation With Antioxidant Nutrients: A Post Hoc Analysis of the French Randomized Trial SU.VI.MAX

This studys objective was to investigate healthy aging in older French adults 5 years after a period of daily nutritional-dose supplementation with antioxidant nutrients. The study was based on the double-blind, randomized trial, Supplementation with Antioxidant Vitamins and Minerals (SU.VI.MAX) Study (1994-2002) and the SU.VI.MAX 2 Follow-up Study (2007-2009). During 1994-2002, participants received a daily combination of vitamin C (120 mg), β-carotene (6 mg), vitamin E (30 mg), selenium (100 µg), and zinc (20 mg) or placebo. Healthy aging was assessed in 2007-2009 by using multiple criteria, including the absence of major chronic disease and good physical and cognitive functioning. Data from a subsample of the SU.VI.MAX 2 cohort, initially free of major chronic disease, with a mean age of 65.3 years in 2007-2009 (n = 3,966), were used to calculate relative risks. Supplementation was associated with a greater healthy aging probability among men (relative risk = 1.16, 95% confidence interval: 1.04, 1.29) but not among women (relative risk = 0.98, 95% confidence interval: 0.86, 1.11) or all participants (relative risk = 1.07, 95% confidence interval: 0.99, 1.16). Moreover, exploratory subgroup analyses indicated effect modification by initial serum concentrations of zinc and vitamin C. In conclusion, an adequate supply of antioxidant nutrients (equivalent to quantities provided by a balanced diet rich in fruits and vegetables) may have a beneficial role for healthy aging.

Association Between Adherence to the Mediterranean Diet at Midlife and Healthy Aging in a Cohort of French Adults

Background The Mediterranean diet has been suggested as a key element for the prevention of age-related chronic diseases. However, very few studies have examined its relation with multidimensional concepts of healthy aging (HA). Our objective was thus to investigate the association between adherence to the Mediterranean diet at midlife and HA. Methods We analyzed data from 3,012 participants of the French SUpplémentation en Vitamines et Minéraux AntioXydants (SU.VI.MAX) study aged 45-60 years at baseline (1994-1995) and initially free of major chronic diseases, with available data on HA status in 2007-2009. We defined HA as not developing major chronic disease (cancer, cardiovascular disease, or diabetes), good physical and cognitive functioning (evaluated by validated, standardized tests), independence in instrumental activities of daily living, no depressive symptoms, good social functioning, good self-perceived health, and no function-limiting pain. An index assessing adherence to the Mediterranean diet, the Literature-based Adherence Score to the Mediterranean Diet (LAMD) was calculated using baseline data from repeated 24-hour dietary records. Results In 2007-2009, 38% of participants met the HA criteria. Multivariable logistic regression revealed that higher scores on the LAMD (ORTertile 3 vs Tertile 1: 1.36 [1.12; 1.65]) were associated with higher odds of HA. Supplementary analyses using structural equation modeling revealed a potential mediation of the observed associations by metabolic health-related factors. Conclusions Our results suggest a favorable role of a high adherence to the Mediterranean diet at midlife for maintaining good overall health during aging.

The Inflammatory Potential of the Diet Is Associated with Depressive Symptoms in Different Subgroups of the General Population

Background: Low-grade chronic inflammation, which can be modulated by diet, has been suggested as an important risk factor for depression, but few studies have investigated the association between the inflammatory potential of the diet and depression.Objective: We investigated the prospective association between the inflammatory potential of the diet, measured by the Dietary Inflammatory Index (DII), and incident depressive symptoms and tested the potential modulating effect of sex, age, physical activity, and smoking status.Methods: This study included 3523 participants (aged 35-60 y) from the SU.VI.MAX (Supplémentation en Vitamines et Minéraux Antioxydants) cohort, who were initially free of depressive symptoms. Baseline DII (1994-1996) was computed by using repeated 24-h dietary records. Incident depressive symptoms were defined by a Center for Epidemiologic Studies-Depression Scale score ≥17 for men and ≥23 for women in 2007-2009. We used multivariable logistic regression models to estimate ORs and 95% CIs, and modeled the DII as a continuous variable and as sex-specific quartiles.Results: A total of 172 cases of incident depressive symptoms were identified over a mean follow-up of 12.6 y. The DII was not associated with incident depressive symptoms in the full sample. In sex-specific models, men with a higher DII had a higher risk of incident depressive symptoms (quartile 4 compared with quartile 1-OR: 2.32; 95% CI: 1.01, 5.35), but the association was only marginally significant (P-trend = 0.06). When analyses were performed across smoking status, current and former smokers with a higher DII had a higher risk of incident depressive symptoms (quartile 4 compared with quartile 1-OR: 2.21; 95% CI: 1.08, 4.52). A positive association was also observed among less physically active participants (quartile 4 compared with quartile 1-OR: 2.07; 95% CI: 1.05, 4.07).Conclusion: The promotion of a healthy diet with anti-inflammatory properties may help to prevent depressive symptoms, particularly among men, smokers, or physically inactive individuals. This trial was registered at clinicaltrials.gov as NCT0027242.

Dietary Quality and 6-Year Anthropometric Changes in a Sample of French Middle-Aged Overweight and Obese Adults

Background Understanding the role of dietary quality in the progression of adiposity in populations already affected by overweight or obesity is crucial for the guidance of secondary prevention strategies. Objective To examine the association of diet quality, as reflected by the French Nutrition and Health Programme (Programme National Nutrition Santé, PNNS) – Guideline Score (GS), with 6-year-changes in weight and waist circumference. Design and Methods Subjects were 1029 male and 450 female participants of the SUplémentation en VItamines et Minéraux AntioXydants (SU.VI.MAX) cohort (1994–2002) with anthropometric variables at baseline and follow-up and available data for estimating diet quality at baseline. We employed analysis of variance and covariance models to investigate anthropometric changes (% of the initial value) by categories of the PNNS-GS, which contains both dietary components and a physical activity component, and of a modified score (mPNNS-GS) containing dietary components only. Results In men, a low (<6 points) PNNS-GS was associated with greater 6-year weight gain (adjusted mean: 3.63% [95% confidence interval: 2.87%; 4.39%]) as compared to a high (≥9 points) PNNS-GS (2.10% [1.39%; 2.81%]); p = 0.01. Results for the mPNNS-GS were very similar. In women, no associations between diet scores and weight change were observed. No significant relation between dietary quality and change in waist circumference was present among either men or women. Conclusions These results support a beneficial role of high dietary quality – as characterized by good adherence to official French nutritional guidelines – in secondary obesity prevention, among men.

Animal Protein Intakes during Early Life and Adolescence Differ in Their Relation to the Growth Hormone-Insulin-Like-Growth-Factor Axis in Young Adulthood

Recent studies provide evidence that insulin-like-growth-factor I (IGF-I) and its binding proteins (IGFBP) IGFBP-2 and IGFBP-3 are related to the risk of several common cancers. It remains to be clarified whether their concentrations can be programmed by protein intake from different sources during growth. This study addressed the hypothesis that animal protein intakes during infancy, mid-childhood, and adolescence differ in their relevance for the growth-hormone (GH)-IGF-I axis in young adulthood. Data from the Dortmund Nutritional and Anthropometric Longitudinally Designed Study participants with at least 2 plausible 3-d weighed dietary records during adolescence (age: girls, 9-14 y; boys, 10-15 y; n = 213), around the adiposity rebound (age 4-6 y; n = 179) or early life (age 0.5-2 y; n = 130), and one blood sample in young adulthood were included in the study. Mean serum concentrations of IGF-I, IGFBP-1, IGFBP-2, and IGFBP-3 were compared between tertiles of habitual animal protein intake using multivariable regression analysis. Habitually higher animal protein intakes in females during puberty were related to higher IGF-I (P-trend = 0.005) and IGFBP-3 (P-trend = 0.01) and lower IGFBP-2 (P-trend = 0.04), but not to IGFBP-1 in young adulthood. In turn, IGF-I concentrations in young adulthood were inversely related to animal protein intakes in early life among males only (P-trend = 0.03), but not to animal protein intake around adiposity rebound (P-trend > 0.5). Our data suggest that, among females, a habitually higher animal protein intake during puberty may precipitate an upregulation of the GH-IGF-I axis, which is still discernible in young adulthood. By contrast, among males, higher animal protein intakes in early life may exert a long-term programming of the GH-IGF-I axis.

Long-term associations between inflammatory dietary scores in relation to long-term C-reactive protein status measured 12 years later: findings from the Supplementation en Vitamines et Mineraux Antioxydants (SU.VI.MAX) cohort

Chronic low-grade inflammation has been recognised as a key underlying mechanism for several chronic diseases, including cancer and CVD. Nutrition represents a host of key modifiable factors that influence chronic inflammation. Dietary inflammatory scores were developed to assess the inflammatory potential of the diet and have been associated with inflammatory biomarkers in cross-sectional and short-term longitudinal studies. The objective of this study was to investigate the relationship between the dietary inflammatory index (DII), the alternate dietary inflammatory index (ADII) and long-term C-reactive protein (CRP). We also tested age as an effect modifier of this relationship. Participants were selected in the Supplémentation en Vitamines et Minéraux Antioxydants study, which included subjects aged 45-60 years old for men and 35-60 years old for women in 1994. Participants with ≥3 24-h dietary records at baseline and a CRP measurement at the 12-year follow-up evaluation were included in the present study (n 1980). The relationships between the DII and ADII and elevated CRP (>3 mg/l) were investigated using logistic multivariable regression. All analyses were stratified by age (cut-off at median age=50 years old). The overall associations between DII and ADII and long-term CRP were not statistically significant (P trend across tertiles=0·16 for DII and 0·10 for ADII). A quantitative interaction was found between ADII score and age (P=0·16 for ADII, 0·36 for DII). In stratified analyses the ADII was significantly prospectively associated with CRP only in younger participants: OR tertile 3 v. tertile 1: 1·79 (95 % CI 1·04, 3·07). Pro-inflammatory diets may have long-term effect on CRP only in younger subjects.