RESUMO
Use of dietary supplements is rising in countries where colorectal cancer is prevalent. We conducted a systematic literature review and meta-analyses of prospective cohort studies on dietary supplement use and colorectal cancer risk. We identified relevant studies in Medline, Embase and Cochrane up to January 2013. Original and peer-reviewed papers on dietary supplement use and colorectal cancer, colon cancer, or rectal cancer incidence were included. "Use-no use"(U-NU), "highest-lowest"(H-L) and "dose-response"(DR) meta-analyses were performed. Random-effects models were used to estimate summary estimates. In total, 24 papers were included in the meta-analyses. We observed inverse associations for colorectal cancer risk and multivitamin (U-NU: RR = 0.92; 95% CI: 0.87,0.97) and calcium supplements (U-NU: RR = 0.86; 95% CI: 0.79,0.95; H-L: RR = 0.80; 95% CI: 0.70,0.92; DR: for an increase of 100 mg/day, RR = 0.96; 95% CI: 0.94,0.99). Inconsistent associations were found for colon cancer risk and supplemental vitamin A and vitamin C, and for colorectal cancer risk and supplemental vitamin D, vitamin E, garlic and folic acid. Meta-analyses of observational studies suggest a beneficial role for multivitamins and calcium supplements on colorectal cancer risk, while the association with other supplements and colorectal cancer risk is inconsistent. Residual confounding of lifestyle factors might be present. Before recommendations can be made, an extensive assessment of dietary supplement use and a better understanding of underlying mechanisms is needed.
Assuntos
Cálcio da Dieta/administração & dosagem , Neoplasias Colorretais/epidemiologia , Suplementos Nutricionais , Vitaminas/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/prevenção & controle , Bases de Dados como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Adulto JovemRESUMO
BACKGROUND: There is clear evidence that nutrition and lifestyle can modify colorectal cancer risk. However, it is not clear if those factors can affect colorectal cancer treatment, recurrence, survival and quality of life. This paper describes the background and design of the "COlorectal cancer: Longitudinal, Observational study on Nutritional and lifestyle factors that may influence colorectal tumour recurrence, survival and quality of life" - COLON - study. The main aim of this study is to assess associations of diet and other lifestyle factors, with colorectal cancer recurrence, survival and quality of life. We extensively investigate diet and lifestyle of colorectal cancer patients at diagnosis and during the following years; this design paper focusses on the initial exposures of interest: diet and dietary supplement use, body composition, nutrient status (e.g. vitamin D), and composition of the gut microbiota. METHODS/DESIGN: The COLON study is a multi-centre prospective cohort study among at least 1,000 incident colorectal cancer patients recruited from 11 hospitals in the Netherlands. Patients with colorectal cancer are invited upon diagnosis. Upon recruitment, after 6 months, 2 years and 5 years, patients fill out food-frequency questionnaires; questionnaires about dietary supplement use, physical activity, weight, height, and quality of life; and donate blood samples. Diagnostic CT-scans are collected to assess cross-sectional areas of skeletal muscle, subcutaneous fat, visceral fat and intermuscular fat, and to assess muscle attenuation. Blood samples are biobanked to facilitate future analyse of biomarkers, nutrients, DNA etc. Analysis of serum 25-hydroxy vitamin D levels, and analysis of metabolomic profiles are scheduled. A subgroup of patients with colon cancer is asked to provide faecal samples before and at several time points after colon resection to study changes in gut microbiota during treatment. For all patients, information on vital status is retrieved by linkage with national registries. Information on clinical characteristics is gathered from linkage with the Netherlands Cancer Registry and with hospital databases. Hazards ratios will be calculated for dietary and lifestyle factors at diagnosis in relation to recurrence and survival. Repeated measures analyses will be performed to assess changes over time in dietary and other factors in relation to recurrence and survival.
Assuntos
Neoplasias Colorretais/dietoterapia , Estilo de Vida , Recidiva Local de Neoplasia/dietoterapia , Qualidade de Vida , Estudos de Coortes , Neoplasias Colorretais/patologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Recidiva Local de Neoplasia/patologia , Países Baixos , Avaliação Nutricional , Estudos Observacionais como Assunto , Estudos Prospectivos , Fatores de Risco , Análise de SobrevidaRESUMO
BACKGROUND AND AIMS: Individuals with Lynch syndrome have a high lifetime risk of developing colorectal tumors. In this prospective cohort study of individuals with Lynch syndrome, we examined associations between use of dietary supplements and occurrence of colorectal adenomas. MATERIALS AND METHODS: Using data of 470 individuals with Lynch syndrome in a prospective cohort study, associations between dietary supplement use and colorectal adenoma risk were evaluated by calculating hazard ratios (HR) and 95% confidence intervals (CI) using cox regression models adjusted for age, sex, and number of colonoscopies during person time. Robust sandwich covariance estimation was used to account for dependency within families. RESULTS: Of the 470 mismatch repair gene mutation carriers, 122 (26.0%) developed a colorectal adenoma during an overall median person time of 39.1 months. 40% of the study population used a dietary supplement. Use of any dietary supplement was not statistically significantly associated with colorectal adenoma risk (HRâ=â1.18; 95%CI 0.80-1.73). Multivitamin supplement use (HRâ=â1.15; 95%CI 0.72-1.84), vitamin C supplement use (HRâ=â1.57; 95%CI 0.93-2.63), calcium supplement use (HRâ=â0.69; 95%CI 0.25-1.92), and supplements containing fish oil (HRâ=â1.60; 95%CI 0.79-3.23) were also not associated with occurrence of colorectal adenomas. CONCLUSION: This prospective cohort study does not show inverse associations between dietary supplement use and occurrence of colorectal adenomas among individuals with Lynch syndrome. Further research is warranted to determine whether or not dietary supplement use is associated to colorectal adenoma and colorectal cancer risk in MMR gene mutation carriers.
Assuntos
Adenoma/complicações , Neoplasias Colorretais Hereditárias sem Polipose/complicações , Neoplasias Colorretais/complicações , Suplementos Nutricionais , Adenoma/epidemiologia , Adulto , Neoplasias Colorretais/epidemiologia , Reparo de Erro de Pareamento de DNA/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Estudos ProspectivosRESUMO
Diet and lifestyle influence colorectal adenoma recurrence. The role of dietary supplement use in colorectal adenoma recurrence remains controversial. In this prospective cohort study, we examined the association between dietary supplement use, total colorectal adenoma recurrence and advanced adenoma recurrence. Colorectal adenoma cases (n = 565) from a former case-control study, recruited between 1995 and 2002, were prospectively followed until 2008. Adenomas with a diameter of ≥1 cm and/or (tubulo)villous histology and/or with high grade dysplasia and/or ≥3 adenomas detected at the same colonic examination were considered advanced adenomas. Hazard ratios (HRs) and 95% confidence intervals (CIs) for dietary supplement users (use of any supplement during the past year) compared to nonusers and colorectal adenoma recurrence were calculated using stratified Cox proportional hazard models for counting processes and were adjusted for age, sex, educational level and number of colonoscopies during follow-up. Robust sandwich covariance estimation was used to adjust for the within subject correlation. A number of 165 out of 565 adenoma patients had at least one colorectal adenoma recurrence during a median person-time of 5.4 years and of these, 37 patients had at least one advanced adenoma. One-third of the total study population (n = 203) used a dietary supplement. Compared to no use, dietary supplement use was neither statistically significantly associated with total colorectal adenoma recurrence (HR = 1.03; 95% CI 0.79-1.34) nor with recurrent advanced adenomas (HR = 1.59; 95% CI 0.88-2.87). This prospective cohort study did not suggest an association between dietary supplement use and colorectal adenoma recurrence.
Assuntos
Adenoma/epidemiologia , Neoplasias Colorretais/epidemiologia , Suplementos Nutricionais/efeitos adversos , Recidiva Local de Neoplasia/epidemiologia , Adenoma/etiologia , Estudos de Coortes , Colonoscopia , Neoplasias Colorretais/etiologia , Dieta , Detecção Precoce de Câncer , Comportamento Alimentar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/etiologia , Modelos de Riscos Proporcionais , Estudos ProspectivosRESUMO
BACKGROUND: Epidemiologic and experimental data suggest a cardioprotective effect of n-3 (omega-3) fatty acids from fish [eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA)]. OBJECTIVE: The objective was to examine the association of fish and EPA plus DHA intakes with coronary calcification in a general older population. DESIGN: Diet was assessed between 1990 and 1993 by using a semiquantitative 170-item food-frequency questionnaire. Coronary calcification was assessed approximately 7 y later by electron-beam computed tomography in 1570 asymptomatic cardiac subjects with complete dietary data (44% men, mean age of 64 y). Calcium scores according to Agatston's method were divided into < or = 10 (no/minimal coronary calcification), 11-400 (mild/moderate calcification), and > 400 (severe calcification). Prevalence ratios (PRs) for mild/moderate and severe calcification were obtained in categories of fish and EPA plus DHA intake. PRs were adjusted for age, sex, body mass index, diabetes mellitus, socioeconomic status, smoking, alcohol intake, physical activity, and dietary factors. RESULTS: Subjects with a fish intake > 19 g/d had a significantly lower prevalence of mild/moderate calcification (PR: 0.87; 95% CI: 0.78, 0.98; full model) than did subjects who consumed no fish. Subjects with a high fish intake also had a lower prevalence of severe calcification (PR: 0.88; 95% CI: 0.74, 1.04), which was borderline statistically significant. EPA plus DHA intake showed no significant associations (PR: 0.93 and 0.97, respectively; P > 0.05). CONCLUSIONS: We found a weak inverse association between fish intake and coronary calcification. If confirmed in other population-based studies, more research is warranted to determine which components in fish can inhibit vascular calcification.