Mélanie Deschasaux

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.

Alcoholic beverages, obesity, physical activity and other nutritional factors, and cancer risk: A review of the evidence

PURPOSE Prevention is a priority in the fight against cancers, especially nutritional prevention. To update the levels of evidence of relationships between 10 nutritional factors and cancer risk, the scientific literature published from 2006 to 2014 was reviewed by an expert group. METHODS Data from 133 meta-analyses, pooled analyses or intervention trials were examined. Nearly 150 relationships between nutritional factors and cancer at various sites were evaluated. RESULTS According to the evidence graded as convincing or probable, these factors were divided in two groups. Factors which increase the risk of cancer are alcoholic beverages, overweight and obesity, red meat and processed meat, salt and salted foods and beta-carotene supplements. Factors which decrease the risk of cancer are physical activity, fruits and vegetables, dietary fiber, dairy products and breastfeeding. CONCLUSION Three main nutritional objectives should be attained to improve cancer prevention: to reduce alcoholic beverages consumption, to have a balanced and diversified diet and to be physically active.

Interpretation of Plasma PTH Concentrations According to 25OHD Status, Gender, Age, Weight Status, and Calcium Intake: Importance of the Reference Values

CONTEXT Reference values for plasma PTH assessment were generally established on small samples of apparently healthy subjects, without considering their 25-hydroxyvitamin D (25OHD) status or other potential modifiers of PTH concentration. OBJECTIVE Our objective was to assess ranges of plasma PTH concentration in a large sample of adults, stratifying by 25OHD status, age, gender, weight status, and calcium intake. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional survey is based on 1824 middle-aged Caucasian adults from the Supplémentation en Vitamines et Minéraux Antioxydants study (1994). MAIN OUTCOME MEASURES Plasma PTH and 25OHD concentrations were measured by an electrochemoluminescent immunoassay. Extreme percentiles of plasma PTH concentrations were assessed specifically in subjects who had plasmatic values of 25OHD of 20 ng/mL or greater and 30 ng/mL or greater. RESULTS Among subjects with 25OHD status of 20 ng/mL or greater, the 97.5th percentile of plasma PTH concentration was 45.5 ng/L. By using this value as a reference, 5% of the subjects with plasma 25OHD less than 20 nmol/L had a high plasma PTH level, reflecting secondary hyperparathyroidism. Among vitamin D-replete subjects (25OHD status of 20 ng/mL or greater), the 97.5th percentile of plasma PTH was higher in overweight/obese subjects (51.9 vs 43.5 ng/L among normal weight subjects). CONCLUSIONS The reference value for plasma PTH defined in this vitamin D-replete population was far below the value currently provided by the manufacturer (65 ng/L) and varied according to overweight status. These results may contribute to improve the diagnosis of primary and secondary hyperparathyroidism and subsequent therapeutic indication.

Dietary Total and Insoluble Fiber Intakes Are Inversely Associated with Prostate Cancer Risk

Although experimental data suggest a potentially protective involvement of dietary fiber in prostate carcinogenesis, very few prospective studies have investigated the relation between dietary fiber intake and prostate cancer risk, and those have had inconsistent results. Our objective was to study the association between dietary fiber intake (overall, insoluble, soluble, and from different sources, such as cereals, vegetables, fruits, and legumes) and prostate cancer risk. Stratifications by excess weight status, insulin-like growth factors, and amount of alcohol intake were also considered. This prospective analysis included 3313 men from the Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) cohort who completed at least 3 24-h dietary records. One hundred thirty-nine incident prostate cancers were diagnosed between 1994 and 2007 (median follow-up of 12.6 y). Associations between quartiles of energy-adjusted dietary fiber intake and prostate cancer risk were characterized by multivariate Cox proportional hazards models. Prostate cancer risk was inversely associated with total dietary fiber intake (HR of quartile 4 vs. quartile 1 = 0.47; 95% CI: 0.27, 0.81; P = 0.001), insoluble (HR = 0.46; 95% CI: 0.27, 0.78; P = 0.001), and legume (HR = 0.55; 95% CI: 0.32, 0.95; P = 0.04) fiber intakes. In contrast, we found no association between prostate cancer risk and soluble (P = 0.1), cereal (P = 0.7), vegetable (P = 0.9), and fruit (P = 0.4) fiber intakes. In conclusion, dietary fiber intake (total, insoluble, and from legumes but not soluble or from cereals, vegetables, and fruits) was inversely associated with prostate cancer risk, consistent with mechanistic data.

A meta-analysis of individual participant data reveals an association between circulating levels of IGF-I and prostate cancer risk

The role of insulin-like growth factors (IGF) in prostate cancer development is not fully understood. To investigate the association between circulating concentrations of IGFs (IGF-I, IGF-II, IGFBP-1, IGFBP-2, and IGFBP-3) and prostate cancer risk, we pooled individual participant data from 17 prospective and two cross-sectional studies, including up to 10,554 prostate cancer cases and 13,618 control participants. Conditional logistic regression was used to estimate the ORs for prostate cancer based on the study-specific fifth of each analyte. Overall, IGF-I, IGF-II, IGFBP-2, and IGFBP-3 concentrations were positively associated with prostate cancer risk (Ptrend all ≤ 0.005), and IGFBP-1 was inversely associated weakly with risk (Ptrend = 0.05). However, heterogeneity between the prospective and cross-sectional studies was evident (Pheterogeneity = 0.03), unless the analyses were restricted to prospective studies (with the exception of IGF-II, Pheterogeneity = 0.02). For prospective studies, the OR for men in the highest versus the lowest fifth of each analyte was 1.29 (95% confidence interval, 1.16-1.43) for IGF-I, 0.81 (0.68-0.96) for IGFBP-1, and 1.25 (1.12-1.40) for IGFBP-3. These associations did not differ significantly by time-to-diagnosis or tumor stage or grade. After mutual adjustment for each of the other analytes, only IGF-I remained associated with risk. Our collaborative study represents the largest pooled analysis of the relationship between prostate cancer risk and circulating concentrations of IGF-I, providing strong evidence that IGF-I is highly likely to be involved in prostate cancer development. Cancer Res; 76(8); 2288-300. ©2016 AACR.

Prospective association between the Dietary Inflammatory Index and mortality: modulation by antioxidant supplementation in the SU.VI.MAX randomized controlled trial

BACKGROUND Chronic inflammation is a central mechanism involved in cardiovascular diseases, cancer, diabetes, and chronic respiratory diseases, 4 leading causes of mortality. Diet is a major source of pro- and anti-inflammatory bioactive compounds. The Dietary Inflammatory Index (DII) was designed to estimate the overall inflammatory potential of the diet. OBJECTIVE Our aim was to study the prospective association between the DII and mortality, as well as assess whether antioxidant supplementation could modulate this association. DESIGN The Supplémentation en Vitamines et Minéraux Antioxydants study was a randomized, double-blind, placebo-controlled trial in which participants received low-dose antioxidants or a placebo from 1994 to 2002. In this observational prospective analysis, 8089 participants (mean ± SD age at baseline: 49.0 ± 6.3 y) were followed between 1994 and 2007 (median: 12.4 y). The DII was calculated from repeated 24-h dietary records; higher scores correspond to more proinflammatory diets. A total of 207 deaths occurred during follow-up, including 123 due to cancer and 41 due to cardiovascular events. Multivariate Cox proportional hazards models were computed. RESULTS Sex-specific tertiles of the DII were positively associated with cardiovascular + cancer mortality (HR for tertile 3 compared with tertile 1 = 1.53; 95% CI: 1.01, 2.32; P-trend = 0.05) and specific cancer mortality (HR for tertile 3 compared with tertile 1 = 1.83; 95% CI: 1.12, 2.99; P-trend = 0.02). The corresponding P value was 0.07 for all-cause mortality. The DII was statistically significantly associated with increased all-cause mortality in the placebo group (HR for tertile 3 compared with tertile 1 = 2.10; 95% CI: 1.15, 3.84; P-trend = 0.02) but not in the antioxidant-supplemented group (P-trend = 0.8; P-interaction = 0.098). CONCLUSION These results suggest that a proinflammatory diet is associated with increased all-cause and cancer mortality and antioxidants may counteract some of the proinflammatory effects of the diet. This trial was registered at clinicaltrials.gov as NCT00272428.

Prospective Association between Dietary Fiber Intake and Breast Cancer Risk

Background Mechanistic hypotheses suggest a potential effect of dietary fiber on breast carcinogenesis through the modulation of insulin-like growth factor bioactivity, estrogen metabolism and inflammation. An association between dietary fiber intake and breast cancer risk has been suggested in epidemiological studies but remains inconclusive. In particular, data is lacking regarding the different types of dietary fibers. Objective The objective was to investigate the prospective relationship between dietary fiber intake and breast cancer risk, taking into account different types of dietary fiber (overall, insoluble, soluble and from different food sources: cereals, vegetables, fruits and legumes). Design 4684 women from the SU.VI.MAX cohort were included in this analysis as they completed at least three 24h-dietary records within the first two years of follow-up. Among them, 167 incident invasive breast cancers were diagnosed during a median follow-up of 12.6 years (between 1994 and 2007). The associations between quartiles of dietary fiber intake and breast cancer risk were characterized using multivariate Cox proportional hazards models. Results Total fiber intake was not associated with breast cancer risk (HRQuartile4vs.Quartile1 = 1.29 (95%CI 0.66–2.50), P-trend = 0.5), nor was fiber intake from cereals (P-trend = 0.1), fruits (P-trend = 0.9) and legumes (P-trend = 0.3). In contrast, vegetable fiber intake was related to a decreased risk of breast cancer (HRQ4vs.Q1 = 0.50 (0.29-0.88), P-trend = 0.03). Overall vegetable intake (in g/day) was not associated with breast cancer risk (P-trend = 0.2). Conclusion This prospective study suggests that vegetable fiber intake may contribute to reduce breast cancer risk, in line with experimental mechanistic data.

Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort

Abstract Objective To assess the prospective associations between consumption of ultra-processed food and risk of cancer. Design Population based cohort study. Setting and participants 104 980 participants aged at least 18 years (median age 42.8 years) from the French NutriNet-Santé cohort (2009-17). Dietary intakes were collected using repeated 24 hour dietary records, designed to register participants’ usual consumption for 3300 different food items. These were categorised according to their degree of processing by the NOVA classification. Main outcome measures Associations between ultra-processed food intake and risk of overall, breast, prostate, and colorectal cancer assessed by multivariable Cox proportional hazard models adjusted for known risk factors. Results Ultra-processed food intake was associated with higher overall cancer risk (n=2228 cases; hazard ratio for a 10% increment in the proportion of ultra-processed food in the diet 1.12 (95% confidence interval 1.06 to 1.18); P for trend<0.001) and breast cancer risk (n=739 cases; hazard ratio 1.11 (1.02 to 1.22); P for trend=0.02). These results remained statistically significant after adjustment for several markers of the nutritional quality of the diet (lipid, sodium, and carbohydrate intakes and/or a Western pattern derived by principal component analysis). Conclusions In this large prospective study, a 10% increase in the proportion of ultra-processed foods in the diet was associated with a significant increase of greater than 10% in risks of overall and breast cancer. Further studies are needed to better understand the relative effect of the various dimensions of processing (nutritional composition, food additives, contact materials, and neoformed contaminants) in these associations. Study registration Clinicaltrials.gov NCT03335644.

Prospective association between a dietary quality index based on a nutrient profiling system and cardiovascular disease risk.

Background Public health strategies are essential to guide consumers’ choices and produce a substantial population impact on cardiovascular disease risk prevention through nutrition. Our aim was to investigate the prospective association between the Food Standards Agency nutrient profiling system dietary index (FSA-NPS DI) and cardiovascular disease risk. The FSA-NPS has been proposed to serve as a basis for a five-colour nutrition label suggested in France to be put on the front of pack of food products. Methods and results A total of 6515 participants to the SU.VI.MAX cohort (1994–2007), who completed at least six 24-hour dietary records during the first two years of the study, were followed for a median of 12.4 years (25th–75th percentiles: 11.0–12.6). Multivariable Cox proportional hazards models were used to characterise the associations between FSA-NPS DI (continuous and sex-specific quartiles) and the incidence of cardiovascular diseases. Interactions with individual characteristics were tested; 181 major cardiovascular events were reported (59 myocardial infarctions, 43 strokes, 79 anginas). A higher FSA-NPS DI, characterising poorer food choices, was associated with an overall increase in cardiovascular disease risk (HRfor a 1-point increment = 1.14 (1.03–1.27); HRQ4vs.Q1 = 1.61 (1.05–2.47), Ptrend Q4-Q1 = 0.03). This association tended to be stronger in smokers (HRfor a 1-point increment = 1.39 (1.11–1.73); Pinteraction = 0.01) and those less physically active (HRfor a 1-point increment = 1.26 (1.08–1.46); Pinteraction = 0.04). Conclusions Our results suggest that poorer food choices, as reflected by a higher FSA-NPS DI, may be associated with a significant increase in cardiovascular risk, especially in at-risk individuals (smokers and physically inactive persons). This score could be a useful tool for public health prevention strategies. Clinical trial registration ClinicalTrials.gov identifier: NCT00272428.

Prospective association between cancer risk and an individual dietary index based on the British Food Standards Agency Nutrient Profiling System.

The Food Standards Agency Nutrient Profiling System (FSA-NPS) constitutes the basis for the Five-Colour Nutrition Label suggested in France to be put on the front-of-pack of food products. At the individual level, a dietary index (FSA-NPS DI) has been derived and validated and corresponds to a weighted mean of all FSA-NPS scores of foods usually consumed by the individual, reflecting the nutritional quality of his/her diet. Our aim was to investigate the association between the FSA-NPS DI and cancer risk in a large cohort. This prospective study included 6435 participants to the SUpplémentation en VItamines et Minéraux AntioXydants cohort (1994-2007) who completed at least six 24 h dietary records during the first 2 years of follow-up. FSA-NPS DI was computed for each subject (higher values representing lower nutritional quality of the diet). After a median follow-up of 12·6 years, 453 incident cancers were diagnosed. Associations were characterised by multivariate Cox proportional hazards models. The FSA-NPS DI was directly associated with overall cancer risk (hazard ratio (HR)for a 1-point increment=1·08 (95 % CI 1·01, 1·15), P trend=0·02; HRQ5 v. Q1=1·34 (95 % CI 1·00, 1·81), P trend=0·03). This association tended to be more specifically observed in subjects with moderate energy intake (≤median, HRfor a 1-point increment=1·10 (95 % CI 1·01-1·20), P trend=0·03). No association was observed in subjects with higher energy intake (P trend=0·3). Results were not statistically significant for breast and prostate cancer risks. For the first time, this study investigated the prospective association between the FSA-NPS individual score and cancer risk. The results suggest that unhealthy food choices may be associated with a 34 % increase in overall cancer risk, supporting the public health relevance of developing front-of-pack nutrition labels based on this score.