Supplemental B-Vitamins and Risk of Upper Gastrointestinal Cancers in the Women's Health Initiative.

B-vitamins contribute to DNA synthesis, maintenance, and regulation. Few studies have examined associations of supplemental sources of B-vitamins with the incidence of upper gastrointestinal (GI) cancers [including gastric (GCA) and esophageal (ECA) cancers]; the only prior study to comprehensively examine such intakes reported potential elevated risks of ECA. We examined 159,401 postmenopausal women, ages 50-79 years at baseline, including 302 incident GCA and 183 incident ECA cases, over 19 years of follow-up within the Women's Health Initiative observational study and clinic trials. Adjusted Cox regression models estimated hazard ratios (HR) and 95% confidence intervals (CI) for associations of supplemental B-vitamins [riboflavin (B2), pyridoxine (B6), folic acid (B9), or cobalamin (B12)] with GCA and ECA risk, respectively. Although HRs were generally below 1.0, we observed no statistically significant associations between supplemental intakes of any of the evaluated B-vitamins with the risk of GCA or ECA. As the first prospective study to comprehensively assess these associations, our findings do not corroborate prior research indicating potential harm from supplemental B-vitamin intake for upper GI cancer risk. This study adds evidence that supplemental intakes of B-vitamins may be used by postmenopausal women without regard to their relationship with upper GI cancer risk.

No Association Observed between Coffee Intake and Risk of Non-Hodgkin Lymphoma among Postmenopausal Women.

BACKGROUND: Some preliminary studies indicate that components in coffee may have anticarcinogenic effects. However, the association between coffee-drinking habits and the risk of non-Hodgkin lymphoma (NHL) remain controversial. OBJECTIVE: To examine the relationship between coffee intake and NHL incidence in a large prospective study of postmenopausal US women. DESIGN AND PARTICIPANTS/SETTING: The participants included 74,935 women from the Women's Health Initiative Observational Study who were recruited from 1993 through 1998. Information about coffee-drinking habits was collected at baseline via self-administered questionnaires. MAIN OUTCOME MEASURES: Newly diagnosed NHL was validated by medical records and pathology records. Separate analyses were performed for the following three subtypes of NHL: diffuse large B-cell lymphoma (n = 244), follicular lymphoma (n = 166), and chronic lymphocytic leukemia/small lymphocytic lymphoma (n = 64). STATISTICAL ANALYSES PERFORMED: Age-adjusted and multivariable-adjusted Cox proportional hazards models were used to determine associations of coffee intake (specifically, the total amount of coffee consumed daily, coffee types, and coffee preparation methods) with risk of NHL. RESULTS: A total of 851 women developed NHL during a median 18.34 years of follow-up (range = 0.01 to 24.30 years; ± 6.63 years). Overall, no associations were observed between coffee intake and risk of NHL regardless of the total amount of daily coffee intake (P value for trend = 0.90), caffeinated (P = 0.55) or decaffeinated coffee intake (P = 0.78), and filtered or unfiltered coffee intake (P = 0.91) after controlling for sociodemographic factors, lifestyle risk factors, and clinical risk factors/current medical conditions. No significant associations were observed between coffee intake with specific subtypes of NHL. A statistically significant interaction was found between alcohol intake, coffee intake, and incident NHL (P value for interaction = 0.02) based on the adjusted analysis. Specifically, among women who frequently consumed alcohol (> 7 drinks/week), those who had moderate coffee intake (2 to 3 c coffee/day) had a significantly reduced risk of developing NHL (hazard ratio 0.61, 95% CI 0.36 to 0.98), compared with those who did not drink coffee. CONCLUSIONS: The findings from this study do not support an association between coffee consumption and NHL risk, irrespective of the total amount of daily coffee intake, coffee types, or coffee preparation methods.

Association of Oily and Nonoily Fish Consumption and Fish Oil Supplements With Incident Type 2 Diabetes: A Large Population-Based Prospective Study.

OBJECTIVE: To evaluate associations of oily and nonoily fish consumption and fish oil supplements with incident type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: We included 392,287 middle-aged and older participants (55.0% women) in the UK Biobank who were free of diabetes, major cardiovascular disease, and cancer and had information on habitual intake of major food groups and use of fish oil supplements at baseline (2006-2010). Of these, 163,706 participated in one to five rounds of 24-h dietary recalls during 2009-2012. RESULTS: During a median 10.1 years of follow-up, 7,262 incident cases of T2D were identified. Compared with participants who reported never consumption of oily fish, the multivariable-adjusted hazard ratios of T2D were 0.84 (95% CI 0.78-0.91), 0.78 (0.72-0.85), and 0.78 (0.71-0.86) for those who reported <1 serving/week, weekly, and ≥2 servings/week of oily fish consumption, respectively (P-trend < 0.001). Consumption of nonoily fish was not associated with risk of T2D (P-trend = 0.45). Participants who reported regular fish oil use at baseline had a 9% (95% CI 4-14%) lower risk of T2D compared with nonusers. Baseline regular users of fish oil who also reported fish oil use during at least one of the 24-h dietary recalls had an 18% (8-27%) lower risk of T2D compared with constant nonusers. CONCLUSIONS: Our findings suggest that consumption of oily fish but not nonoily fish was associated with a lower risk of T2D. Use of fish oil supplements, especially constant use over time, was also associated with a lower risk of T2D.

Dietary B-Vitamin Intake and Risk of Breast, Endometrial, Ovarian and Colorectal Cancer among Canadians.

Few studies have explored the associations of thiamin, niacin and riboflavin with risk of cancer despite their role in potentially cancer-associated one-carbon metabolism. Using multivariable Cox proportional hazards regression models modified for the case-cohort design, we examined the associations of dietary intake of the above-mentioned B vitamins, as well as folate, and vitamins B6 and B12, with risk of the breast (n = 922), endometrial (n = 180), ovarian (n = 104) and colorectal (n = 266) cancers among age-stratified subcohorts of 3,185 women who were randomly selected from a cohort of 73,909 participants. None of the B-vitamins were associated with risk of breast or colorectal cancers. However, relatively high dietary intake of folate intake was inversely associated with risk of endometrial (HRq4 vs q1: 0.52; 95% CI: 0.29-0.93) and ovarian (HRq3 vs q1: 0.39; 95% CI: 0.19-0.80) cancers while relatively high dietary intake of vitamin B6 was inversely associated with ovarian cancer risk (HRq3 vs q1: 0.49; 95% CI: 0.24-0.98). These findings suggest that dietary intake of folate may reduce risk of endometrial and ovarian cancers and dietary intake of vitamin B6 may reduce risk of ovarian cancer.

Associations of coffee, tea and caffeine intake with risk of breast, endometrial and ovarian cancer among Canadian women.

BACKGROUND: Although, biologically plausible evidence has implicated coffee, tea and caffeine with carcinogenesis, there is a paucity of data on their associations with risk of cancer among Canadian women. Hence, we assessed their associations with risk of breast, endometrial and ovarian cancers within this population. METHODS: The study comprised a subcohort of 3185 women from a cohort of 39,532 female participants who completed self-administered lifestyle and dietary questionnaires at enrollment. During a median follow-up of approximately 12.2years, we ascertained 922, 180 and 104 breast, endometrial and ovarian cancer cases, respectively. We used Cox proportional hazards regression models modified for the case-cohort design to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for the associations of coffee, tea and caffeine with risk of selected cancers. RESULTS: Coffee, tea, and caffeine intake were not associated with overall risk of breast and ovarian cancers. There was, however, a tendency towards an increased risk of breast cancer with increasing levels of total coffee, caffeinated coffee and/or caffeine among premenopausal and normal weight women. Total coffee, caffeinated coffee, and caffeine were inversely associated with risk of endometrial cancer (HRper cup increase: 0.88; 95% CI: 0.79-0.95, HRper cup increase: 0.88; 95% CI: 0.80-0.96 and HRper 100mg increase: 0.93; 95% CI: 0.87-0.99, respectively). CONCLUSION: Our findings suggest that coffee and/or caffeine may be associated with reduced risk of endometrial cancer but, probably, associated increased with risk of breast cancer among premenopausal or normal weight women. However, further studies are needed to confirm our findings.

Metabolic serum biomarkers for the prediction of cancer: a follow-up of the studies conducted in the Swedish AMORIS study.

The Swedish Apolipoprotein MOrtality RISk study (AMORIS) contains information on more than 500 biomarkers collected from 397,443 men and 414,630 women from the greater Stockholm area during the period 1985-1996. Using a ten-digit personal identification code, this database has been linked to Swedish national registries, which provide data on socioeconomic status, vital status, cancer diagnosis, comorbidity, and emigration. Within AMORIS, 18 studies assessing risk of overall and site-specific cancers have been published, utilising a range of serum markers representing glucose and lipid metabolism, immune system, iron metabolism, liver metabolism, and bone metabolism. This review briefly summarises these findings in relation to more recently published studies and provides an overview of where we are today and the challenges of observational studies when studying cancer risk prediction. Overall, more recent observational studies supported previous findings obtained in AMORIS, although no new results have been reported for serum fructosamine and inorganic phosphate with respect to cancer risk. A drawback of using serum markers in predicting cancer risk is the potential fluctuations following other pathological conditions, resulting in non-specificity and imprecision of associations observed. Utilisation of multiple combination markers may provide more specificity, as well as give us repeated instead of single measurements. Associations with other diseases may also necessitate further analytical strategies addressing effects of serum markers on competing events in addition to cancer. Finally, delineating the role of serum metabolic markers may generate valuable information to complement emerging clinical studies on preventive effects of drugs and supplements targeting metabolic disorders against cancer.