Philippine Fassier

Cholesterol and breast cancer risk: a systematic review and meta-analysis of prospective studies.

The objective of the present study was to conduct the first systematic review and meta-analysis of prospective studies investigating the associations between total cholesterol (TC), HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C) levels and the risk of breast cancer. Relevant studies were identified in PubMed (up to January 2014). Inclusion criteria were original peer-reviewed publications with a prospective design. Random-effects models were used to estimate summary hazard ratios (HR) and 95% CI. Distinction was made between studies that did or did not exclude cancer cases diagnosed during the first years of follow-up, thereby eliminating potential preclinical bias. Overall, the summary HR for the association between TC and breast cancer risk was 0.97 (95% CI 0.94, 1.00; dose-response per 1 mmol/l increment, thirteen studies), and that between HDL-C and breast cancer risk was 0.86 (95% CI 0.69, 1.09; dose-response per 1 mmol/l increment, six studies), with high heterogeneity (I2= 67 and 47%, respectively). For studies that eliminated preclinical bias, an inverse association was observed between the risk of breast cancer and TC (dose-response HR 0.94 (95% CI 0.89, 0.99), seven studies, I2= 78%; highest v. lowest HR 0.82 (95% CI 0.66, 1.02), nine studies, I2= 81%) and HDL-C (dose-response HR 0.81 (95% CI 0.65, 1.02), five studies, I2= 30 %; highest v. lowest HR 0.82 (95% CI 0.69, 0.98), five studies, I2= 0%). There was no association observed between LDL-C and the risk of breast cancer (four studies). The present meta-analysis confirms the evidence of a modest but statistically significant inverse association between TC and more specifically HDL-C and the risk of breast cancer, supported by mechanistic plausibility from experimental studies. Further large prospective studies that adequately control for preclinical bias are needed to confirm the results on the role of cholesterol level and its fractions in the aetiology of breast cancer.

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 alcohol intake and hormone-dependent cancer risk: modulation by dietary fiber intake

BACKGROUND Alcohol intake is associated with increased circulating concentrations of sex hormones, which in turn may increase hormone-dependent cancer risk. This association may be modulated by dietary fiber intake, which has been shown to decrease steroid hormone bioavailability (decreased blood concentration and increased sex hormone-binding globulin concentration). However, this potential modulation has not been investigated in any prospective cohort. OBJECTIVES Our objectives were to study the relation between alcohol intake and the risk of hormone-dependent cancers (breast, prostate, ovarian, endometrial, and testicular) and to investigate whether dietary fiber intake modulated these associations. DESIGN This prospective observational analysis included 3771 women and 2771 men who participated in the Supplémentation en Vitamines et Minéraux Antioxydants study (1994-2007) and completed at least 6 valid 24-h dietary records during the first 2 y of follow-up. After a median follow-up of 12.1 y, 297 incident hormone-dependent cancer cases, including 158 breast and 123 prostate cancers, were diagnosed. Associations were tested via multivariate Cox proportional hazards models. RESULTS Overall, alcohol intake was directly associated with the risk of hormone-dependent cancers (tertile 3 vs. tertile 1: HR: 1.36; 95% CI: 1.00, 1.84; P-trend = 0.02) and breast cancer (HR: 1.70; 95% CI: 1.11, 2.61; P-trend = 0.04) but not prostate cancer (P-trend = 0.3). In stratified analyses (by sex-specific median of dietary fiber intake), alcohol intake was directly associated with hormone-dependent cancer (tertile 3 vs. tertile 1: HR: 1.76; 95% CI: 1.10, 2.82; P-trend = 0.002), breast cancer (HR: 2.53; 95% CI: 1.30, 4.95; P-trend = 0.02), and prostate cancer (HR: 1.37; 95% CI: 0.65, 2.89; P-trend = 0.02) risk among individuals with low dietary fiber intake but not among their counterparts with higher dietary fiber intake (P-trend = 0.9, 0.8, and 0.6, respectively). The P-interaction between alcohol and dietary fiber intake was statistically significant for prostate cancer (P = 0.01) but not for overall hormone-dependent (P = 0.2) or breast (P = 0.9) cancer. CONCLUSION In line with mechanistic hypotheses and experimental data, this prospective study suggested that dietary fiber intake might modulate the association between alcohol intake and risk of hormone-dependent cancer. This trial was registered at clinicaltrials.gov as NCT00272428.

What Do People Know and Believe about Vitamin D

People have been exposed to a lot of information regarding vitamin D, with evidence suggesting that vitamin D may be involved in numerous health conditions, subsequently creating concerns about vitamin D insufficiency. As a result, what do people really know or believe about this topic? In this cross-sectional study, we assessed vitamin D-related knowledge and beliefs in 59,273 French adults (NutriNet-Santé cohort) using a specific questionnaire. Answers to this questionnaire were weighted according to the French sociodemographic distribution and compared across individual characteristics, using χ2-tests. Physicians and media were identified as key information providers. Participants did not always accurately cite vitamin D sources (e.g., 72% only for sun exposure, fatty fish: 61%) or established health effects (e.g., bone health: 62%–78%). Conversely, they mentioned incorrect sources and health effects for which there is no consensus yet (e.g., skin cancer). These findings were modulated by age/generational and socioeconomic factors. A strong inconsistency was also observed between participants’ true vitamin D status (plasma 25-hydroxyvitamin D concentration) and their opinion about it. This study, the first in Europe with such a large sample, stresses the need for simple and up-to-date supports of communication for the public and healthcare professionals regarding sources and health effects of vitamin D.

How Computer Literacy and Socioeconomic Status Affect Attitudes Toward a Web-Based Cohort: Results From the NutriNet-Santé Study

Background In spite of the growing literature in the field of e-epidemiology, clear evidence about computer literacy or attitudes toward respondent burden among e-cohort participants is largely lacking. Objective We assessed the computer and Internet skills of participants in the NutriNet-Santé Web-based cohort. We then explored attitudes toward the study demands/respondent burden according to levels of computer literacy and sociodemographic status. Methods Self-reported data from 43,028 e-cohort participants were collected in 2013 via a Web-based questionnaire. We employed unconditional logistic and linear regression analyses. Results Approximately one-quarter of participants (23.79%, 10,235/43,028) reported being inexperienced in terms of computer use. Regarding attitudes toward participant burden, women tended to be more favorable (eg, “The overall website use is easy”) than were men (OR 0.65, 95% CI 0.59-0.71, P<.001), whereas better educated participants (>12 years of schooling) were less likely to accept the demands associated with participation (eg, “I receive questionnaires too often”) compared to their less educated counterparts (OR 1.62, 95% CI 1.48-1.76, P<.001). Conclusions A substantial proportion of participants had low computer/Internet skills, suggesting that this does not represent a barrier to participation in Web-based cohorts. Our study also suggests that several subgroups of participants with lower computer skills (eg, women or those with lower educational level) might more readily accept the demands associated with participation in the Web cohort. These findings can help guide future Web-based research strategies.

Variations of physical activity and sedentary behavior between before and after cancer diagnosis: Results from the prospective population-based NutriNet-Santé cohort.

AbstractPhysical activity (PA) but also reduced sedentary behavior may be associated with better prognosis and lower risk of recurrence in cancer patients. Our aim was to quantify the variations in PA and time spent sedentary between before and after diagnosis, relying on prospective data in French adults. We also investigated sociodemographic and lifestyle factors associated with these variations.Subjects (n = 942) were incident cancer cases diagnosed in the NutriNet-Santé cohort between 2009 and 2015. PA and sedentary behavior were prospectively collected with the 7-day short version of the IPAQ questionnaire every year since subjects’ inclusion (i.e., an average of 2 year before diagnosis). All PA and sitting time points before and after diagnosis was compared by mixed model. Factors associated with decrease in PA and increase in sitting time were investigated using logistic regressions.Overall and vigorous PA decreased after diagnosis (P = 0.006, −32.8 ± 36.8 MET-hour/week on average, in those who decreased their overall PA and P = 0.005, −21.1 ± 36.8 MET-hour/week for vigorous PA, respectively), especially in prostate (−39.5 ± 36.3 MET-hour/week) and skin (−35.9 ± 38 MET-hour/week) cancers, in men (−40.8 ± 46.3MET-hour/week), and in those professionally inactive (−34.2 ± 37.1 MET-hour/week) (all P < 0.05). Patients with higher PA level before diagnosis were more likely to decrease their PA (odds ratio [OR]: 4.67 [3.21–6.81], P < 0.0001). Overweight patients more likely to decrease moderate PA (OR: 1.45 [1.11–1.89], P = 0.006) and walking (OR: 1.30 [1.10–1.70], P = 0.04). Sitting time increased (P = 0.02, +2.44 ± 2.43 hour/day on average, in those who increased their sitting time), especially in women (+2.48 ± 2.48 hour/day), older patients (+2.48 ± 2.57 hour/day), and those professionally inactive (2.41 ± 2.40 hour/day) (all P < 0.05). Patients less sedentary before diagnosis were more likely to increase their sitting time (OR: 3.29 [2.45–4.42], P < 0.0001).This large prospective study suggests that cancer diagnosis is a key period for change in PA and sedentary behavior. It provides insights to target the subgroups of patients who are at higher risk of decreasing PA and increasing sedentary behavior after cancer diagnosis.

Red and processed meat intake and cancer risk: Results from the prospective NutriNet-Santé cohort study.

The International Agency for Research on Cancer (WHO‐IARC) classified red meat and processed meat as probably carcinogenic and carcinogenic for humans, respectively. These conclusions were mainly based on studies concerning colorectal cancer, but scientific evidence is still limited for other cancer locations. In this study, we investigated the prospective associations between red and processed meat intakes and overall, breast, and prostate cancer risk. This prospective study included 61,476 men and women of the French NutriNet‐Santé cohort (2009–2015) aged ≥35 y and who completed at least three 24 hrs dietary records during the first year of follow‐up. The risk of developing cancer was compared across sex‐specific quintiles of red and processed meat intakes by multivariable Cox models. 1,609 first primary incident cancer cases were diagnosed during follow‐up, among which 544 breast cancers and 222 prostate cancers. Red meat intake was associated with increased risk of overall cancers [HRQ5vs.Q1=1.31 (1.10–1.55), ptrend = 0.01) and breast cancer (HRQ5vs.Q1 = 1.83 (1.33–2.51), ptrend = 0.002]. The latter association was observed in both premenopausal [HRQ5vs.Q1=2.04 (1.03–4.06)] and postmenopausal women [HRQ5vs.Q1=1.79 (1.26‐2.55)]. No association was observed between red meat intake and prostate cancer risk. Processed meat intake was relatively low in this study (cut‐offs for the 5th quintile = 46 g/d in men and 29 g/d in women) and was not associated with overall, breast or prostate cancer risk. This large cohort study suggested that red meat may be involved carcinogenesis at several cancer locations (other than colon‐rectum), in particular breast cancer. These results are consistent with mechanistic evidence from experimental studies.

Dietary supplement use among cancer survivors of the NutriNet-Santé cohort study

Dietary supplements (DS) may influence cancer prognosis. Their use in cancer patients has been described in the United States, but data are largely lacking in Europe and notably in France. The present studys objectives were (1) to assess DS use and its sociodemographic, lifestyle, and dietary correlates in a large sample of French cancer survivors; (2) to evaluate the involvement of physicians in such DS use; and (3) to assess the extent of potentially harmful practices. Data were collected by self-administered web-based questionnaires among participants of the NutriNet-Santé cohort. Data on DS use was available for 1081 cancer survivors. DS users were compared to non-users with unconditional logistic regressions. DS use was reported by 62% of women and 29% of men. Vitamins D, B6, C and Mg were the most frequently consumed nutrients. 14% of cancer survivors initiated DS use after diagnosis. For 35% of the DS consumed, subjects did not inform their attending physician. DS use was associated with a healthier lifestyle (normal weight, never smoking and better diet) and substantially contributed to nutrient intake. 18% of DS users had potentially harmful DS use practices, such as the simultaneous use of vitamin E and anticoagulant/antiplatelet agents, the use of β-carotene and smoking or the use of phyto-oestrogens in hormone-dependent cancer patients. The present study suggests that DS use is widespread among cancer survivors, a large amount of that use is performed without any medical supervision and a substantial proportion of that use involves potentially harmful practices. Physicians should be encouraged to more routinely discuss DS use with their cancer patients.

Dietary iron intake and breast cancer risk: modulation by an antioxidant supplementation

Experimental results suggested that iron-induced lipid peroxidation may explain the direct associations observed between red/processed meat intakes and colorectal and breast cancer risk. However, epidemiological evidence is lacking. Thus, we investigated the association between dietary iron intake and breast cancer risk, and its potential modulation by an antioxidant supplementation and lipid intake. This prospective study included 4646 women from the SU.VI.MAX trial (daily low-dose antioxidants vs. placebo). 188 incident breast cancers were diagnosed (median follow-up=12.6y). Dietary iron intake was assessed using repeated 24h dietary records. Multivariable Cox proportional hazards models were computed. Dietary iron intake was associated with an increased breast cancer risk (HRT3vs.T1=1.67 (1.02-2.71), P-trend=0.04). This association was observed in the placebo group (HRT3vs.T1=2.80 (1.42-5.54), P-trend=0.003), but not in the antioxidant-supplemented group (P-trend=0.7, P-interaction=0.1). Besides, in the placebo group, the increased breast cancer risk associated with dietary iron intake was more specifically observed in women with higher lipid intake (P-trend=0.046). These findings suggest that dietary iron intake may be associated with an increased breast cancer risk, especially in women who did not received antioxidants during the trial and who consumed more lipids. This supports the experimental results suggesting that breast cancer risk may be increased by iron-induced lipid peroxidation.

Association between Motives for Dish Choices during Home Meal Preparation and Weight Status in the NutriNet-Santé Study

Although home cooking has been associated with a lower body mass index in a few studies, no data exists on the motives behind food dish choices during home meal preparation and on their association with overweight. This study aimed to evaluate this association in 50,003 participants from the NutriNet-Santé cohort. Dimensions underlying the importance of 27 criteria possibly influencing dish choices were determined using an exploratory factor analysis. The association between dish choice motives and overweight (including obesity) was estimated using logistic regression models adjusted for sociodemographic and lifestyle characteristics. Five dimensions of dishes choice motives emerged: healthy diet (e.g., “nutritional balance of the dish”), constraints (e.g., “my cooking skills”), pleasure (e.g., “originality of the dish”), specific diets (e.g., “my health status”), and organization (e.g., “what I planned to eat”). A negative association was observed between the healthy diet factor and being overweight (OR = 0.65 (95% CI (confidence interval): 0.62–0.67)), whereas a positive association appeared for factors regarding pleasure (OR = 1.14 (95% CI: 1.10–1.19)) and specific diets (OR = 1.19 (95% CI: 1.17–1.22)). No significant associations were observed for constraints and organization. The significant associations between dish choice motives and overweight suggested the interest of focusing on these motives in order to promote healthier food choices during home cooking.