A hipótese de que uma dieta rica em gordura promova o desenvolvimento do câncer de mama na menopausa é fortalecida por estudos caso-controle, que mostram forte associação positiva entre uma dieta rica em lipídios e as taxas de incidência de câncer de mama. Por outro lado, a ingestão dietética de gordura não parece estar relacionada com o risco de câncer de mama em estudos de coorte. Em vista desses achados conflitantes, tem sido difícil propor qualquer recomendação nutricional para a prevenção do câncer de mama. Estudos com animais e observações recentes em humanos, entretanto, têm mostrado evidências de que a dieta rica em ácido graxo linoléico estimula vários estágios no desenvolvimento de câncer mamário. Alguns estudos ainda mostram que o óleo de peixe, constituído de ácidos graxos ômega-3, parece prevenir o câncer pela influência sobre a atividade de enzimas e proteínas relacionadas à proliferação celular. Assim, são necessários estudos epidemiológicos que integrem as interações de ácidos graxos específicos com o catabolismo hormonal, fatores nutricionais protetores e de risco relacionados com o câncer de mama. Nesse trabalho, abordaremos os fatores protetores, de risco e as implicações quali e quantitativas dos ácidos graxos da dieta sobre o câncer de mama.

Consumo de bebida alcoólica, fatores socioeconômicos e excesso de peso: um estudo transversal no sul do BrasilAlcohol consumption, social and economic factors and excess weight: a cross-sectional study

The purpose of this study was to evaluate the association between apolipoprotein E (APOE) allelic frequency, serum lipoproteins and breast cancer (BC). We conducted a nested case-control study within a cohort including 47 cases and 165 controls. Polymerase chain reaction-restriction fragment length polymorphism analyses of the APOE polymorphism were performed. In general, participants with the genotype including alleles e2 and e3 tended to have lower serum triglycerides, total cholesterol and low-density lipoprotein cholesterol levels and higher high-density lipoprotein (HDL) cholesterol levels compared to participants homozygous for the e3 allele and participants heterozygous for the e3 and e4 alleles, respectively. BC patients exhibited higher mean levels of total serum cholesterol (P=0.070), dietary fat intake (P=0.020) and dietary cholesterol intake (P=0.017) compared to control subjects. The allelic distribution between the two groups revealed that the presence of the e2 allele was positively associated with the absence of BC, whereas the e4 allele was positively associated with the BC case group (P=0.019). The distribution of the APOE genotypes was not significantly different between cases and controls (P=0.172). The concomitant presence of the e2 and e4 alleles was positively associated with the absence of BC and e4/e4 homozygosity was positively associated with BC (P=0.021). Our findings suggested that APOE polymorphism plays an important role in the development of BC, particularly when associated with higher serum triglyceride levels.

Objectives: To explore the relationship between work-related stress and obesity among female shift workers. Additionally, we also aimed to test the interaction between shift work and work-related stress in this association. Design: A cross-sectional study was conducted among Brazilian female shift workers. Work-related stress was assessed through a demand–control questionnaire (Job Stress Scale). Work-related stress was defined by presence of high psychological demands and low control at work. The obesity cases were defined as those with a body mass index of 30 kg/m2 or more. Multivariate Poisson regression with robust variance was used to obtain the prevalence ratios (PRs) and their respective 95% confidence intervals (95% CIs). Setting: A group of industries located in southern Brazil in 2017. Participants: 420 female workers aged 18–59 years. Results: The overall prevalence of obesity was 30% (95% CI: 25.6 to 34.4) and the presence of work-related stress was identified in 24% (95% CI: 19.9 to 28.1) of the sample. We found an indication of interaction between work-related stress and night shift work on obesity (P = 0.026). After adjusting for confounding factors, work-related stress was associated with a 71% greater probability of obesity (PR = 1.71; 95% CI: 1.02 to 2.87; P = 0.042) among female night shift workers. Conclusions: In this study, we revealed that exposure to work-related stress and night shift work were associated with obesity among female shift workers. Furthermore, the prevalence of obesity was high among female shift workers.