Toenail zinc as a biomarker: Relationship with sources of environmental exposure and with genetic variability in MCC-Spain study.

BACKGROUND: Toenails are commonly used as biomarkers of exposure to zinc (Zn), but there is scarce information about their relationship with sources of exposure to Zn. OBJECTIVES: To investigate the main determinants of toenail Zn, including selected sources of environmental exposure to Zn and individual genetic variability in Zn metabolism. METHODS: We determined toenail Zn by inductively coupled plasma mass spectrometry in 3,448 general population controls from the MultiCase-Control study MCC-Spain. We assessed dietary and supplement Zn intake using food frequency questionnaires, residential proximity to Zn-emitting industries and residential topsoil Zn levels through interpolation methods. We constructed a polygenic score of genetic variability based on 81 single nucleotide polymorphisms in genes involved in Zn metabolism. Geometric mean ratios of toenail Zn across categories of each determinant were estimated from multivariate linear regression models on log-transformed toenail Zn. RESULTS: Geometric mean toenail Zn was 104.1 µg/g in men and 100.3 µg/g in women. Geometric mean toenail Zn levels were 7 % lower (95 % confidence interval 1-13 %) in men older than 69 years and those in the upper tertile of fibre intake, and 9 % higher (3-16 %) in smoking men. Women residing within 3 km from Zn-emitting industries had 4 % higher geometric mean toenail Zn levels (0-9 %). Dietary Zn intake and polygenic score were unrelated to toenail Zn. Overall, the available determinants only explained 9.3 % of toenail Zn variability in men and 4.8 % in women. DISCUSSION: Sociodemographic factors, lifestyle, diet, and environmental exposure explained little of the individual variability of toenail Zn in the study population. The available genetic variants related to Zn metabolism were not associated with toenail Zn.

Allium vegetables intake and the risk of gastric cancer in the Stomach cancer Pooling (StoP) Project.

BACKGROUND: The role of allium vegetables on gastric cancer (GC) risk remains unclear. METHODS: We evaluated whether higher intakes of allium vegetables reduce GC risk using individual participant data from 17 studies participating in the "Stomach cancer Pooling (StoP) Project", including 6097 GC cases and 13,017 controls. Study-specific odds ratios (ORs) were pooled using a two-stage modelling approach. RESULTS: Total allium vegetables intake was inversely associated with GC risk. The pooled OR for the highest versus the lowest study-specific tertile of consumption was 0.71 (95% confidence interval, CI, 0.56-0.90), with substantial heterogeneity across studies (I2 > 50%). Pooled ORs for high versus low consumption were 0.69 (95% CI, 0.55-0.86) for onions and 0.83 (95% CI, 0.75-0.93) for garlic. The inverse association with allium vegetables was evident in Asian (OR 0.50, 95% CI, 0.29-0.86) but not European (OR 0.96, 95% CI, 0.81-1.13) and American (OR 0.66, 95% CI, 0.39-1.11) studies. Results were consistent across all other strata. CONCLUSIONS: In a worldwide consortium of epidemiological studies, we found an inverse association between allium vegetables and GC, with a stronger association seen in Asian studies. The heterogeneity of results across geographic regions and possible residual confounding suggest caution in results interpretation.

Coffee consumption and colorectal cancer risk: a multicentre case-control study from Italy and Spain.

BACKGROUND: Coffee contains many bioactive substances that can play a role on colorectal cancer. Epidemiological evidence of coffee intake and colorectal cancer is, however, inconsistent. AIM: To provide further information on the risk of colorectal cancer in relation to coffee consumption. METHODS: Data derive from two companion case-control studies conducted in Italy and Spain within the European Union Project on Health Impacts of long-term exposure to disinfection by-products in Drinking Water and the Spanish Multi-Case Control study on Cancer. These included a total of 2289 incident cases with colorectal cancer and 3995 controls with information on coffee intake. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were derived from unconditional logistic regression models, adjusted for study centre, sex, age, education, smoking, and other covariates. RESULTS: Compared with never coffee drinkers, the OR was 0.99 (95% CI 0.95-1.02) for total coffee consumption. There was no significant trend in risk with dose or duration, the ORs being 0.95 (95% CI 0.72-1.25) for an amount of five or more cups per day of coffee and 0.95 (95% CI 0.75-1.19) for a duration of consumption of 50 years or longer. The OR was 1.04 (95% CI 0.87-1.25) for two or more cups per day of decaffeinated coffee. There were no heterogeneity across strata of various covariates, as well as no apparent differences between various anatomical subsites. CONCLUSION: This large pooled analysis of two studies shows no association of coffee and decaffeinated coffee with colorectal cancer risk.

Possible role of chondroitin sulphate and glucosamine for primary prevention of colorectal cancer. Results from the MCC-Spain study.

A safe and effective colorectal cancer (CRC) chemoprevention agent remains to be discovered. We aim to evaluate the association between the use of glucosamine and/or chondroitin sulphate and risk of colorectal cancer (CRC) in the MCC-Spain study, a case-control study performed in Spain that included 2140 cases of CRC and 3950 population controls. Subjects were interviewed on sociodemographic factors, lifestyle, family and medical history and regular drug use. Adjusted odds ratios and their 95% confidence intervals were estimated. The reported frequency of chondroitin and/or glucosamine use was 2.03% in controls and 0.89% in cases. Users had a reduced risk of CRC (OR: 0.47; 95% CI: 0.28-0.79), but it was no longer significant when adjusted for NSAID (nonsteroidal anti-inflammatory drugs) use (OR: 0.82; 95% CI: 0.47-1.40). A meta-analysis with previous studies suggested a protective effect, overall and stratified by NSAID use (OR: 0.77; 95% CI: 0.62-0.97). We have not found strong evidence of an independent preventive effect of CG on CRC in our population because the observed effects of our study could be attributed to NSAIDs concurrent use. These results merit further research due to the safety profile of these drugs.

Adherence to nutrition-based cancer prevention guidelines and breast, prostate and colorectal cancer risk in the MCC-Spain case-control study.

Prostate, breast and colorectal cancer are the most common tumours in Spain. The aim of the present study was to evaluate the association between adherence to nutrition-based guidelines for cancer prevention and prostate, breast and colorectal cancer, in the MCC-Spain case-control study. A total of 1,718 colorectal, 1,343 breast and 864 prostate cancer cases and 3,431 population-based controls recruited between 2007 and 2012, were included in the present study. The World Cancer Research Fund/American Institute for Cancer Research (WCRC/AICR) score based on six recommendations for cancer prevention (on body fatness, physical activity, foods and drinks that promote weight gain, plant foods, animal foods and alcoholic drinks; score range 0-6) was constructed. We used unconditional logistic regression analysis adjusting for potential confounders. One-point increment in the WCRF/AICR score was associated with 25% (95% CI 19-30%) lower risk of colorectal, and 15% (95% CI 7-22%) lower risk of breast cancer; no association with prostate cancer was detected, except for cases with a Gleason score ≥7 (poorly differentiated/undifferentiated tumours) (OR 0.87, 95% CI 0.76-0.99). These results add to the wealth of evidence indicating that a great proportion of common cancer cases could be avoided by adopting healthy lifestyle habits.