Effects of Nutrition Intervention on Total and Cancer Mortality: 25-Year Post-trial Follow-up of the 5.25-Year Linxian Nutrition Intervention Trial.

Background: A beneficial effect of supplementation with selenium, vitamin E, and beta-carotene was observed on total and cancer mortality in a Chinese population, and it endured for 10 years postintervention, but longer durability is unknown. Methods: A randomized, double-blind, placebo-controlled trial was conducted in Linxian, China, from 1986 to 1991; 29 584 residents age 40 to 69 years received daily supplementations based on a factorial design: Factors A (retinol/zinc), B (riboflavin/niacin), C (vitamin C/molybdenum), and/or D (selenium/vitamin E/beta-carotene), or placebo for 5.25 years, and followed for up 25 years. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the intervention effects on mortalities were estimated using Cox proportional hazards models. Results: Through 2016, the interventions showed no effect on total mortality. The previously reported protective effect of Factor D against total mortality was lost 10 years postintervention. The protective effect of Factor D for gastric cancer was attenuated (HR = 0.93, 95% CI = 0.85 to 1.01), but a newly apparent protective effect against esophageal cancer was found for Factor B (HR = 0.92, 95% CI = 0.85 to 1.00, two-sided P = .04). Other protective/adverse associations were observed for cause-specific mortalities. Protective effects were found in people younger than age 55 years at baseline against non-upper gastrointestinal cancer death for Factor A (HR = 0.80, 95% CI = 0.69 to 0.92) and against death from stroke for Factor C (HR = 0.89, 95% CI = 0.82 to 0.96). In contrast, increased risk of esophageal cancer was found when the intervention began after age 55 years for Factors C (HR = 1.16, 95% CI = 1.04 to 1.30) and D (HR = 1.20, 95% CI = 1.07 to 1.34). Conclusions: Multiyear nutrition intervention is unlikely to have a meaningful effect on mortality more than a decade after supplementation ends, even in a nutritionally deprived population. Whether sustained or repeat intervention would provide longer effects needs further investigation.

Vitamin D Status and Virologic Response to HCV Therapy in the HALT-C and VIRAHEP-C Trials.

CONCLUSION: Higher vitamin D status was not beneficially associated with responses to therapy; if anything, patients with higher vitamin D concentrations were less likely to attain SVR. Our data do not support a role for vitamin D supplementation as an adjuvant therapy for HCV.

Green tea intake is associated with urinary estrogen profiles in Japanese-American women.

SCOPE: Intake of green tea may reduce the risk of breast cancer; polyphenols in this drink can influence enzymes that metabolize estrogens, known causal factors in breast cancer etiology. METHODS AND RESULTS: We examined the associations of green tea intake (<1 time/week, 1-6 times weekly, or 7+ times weekly) with urinary estrogens and estrogen metabolites (jointly EM) in a cross-sectional sample of healthy Japanese American women, including 119 premenopausal women in luteal phase and 72 postmenopausal women. We fit robust regression models to each log-transformed EM concentration (picomoles per mg creatinine), adjusting for age and study center. In premenopausal women, intake of green tea was associated with lower luteal total EM (P trend=0.01) and lower urinary 16-pathway EM (P trend=0.01). In postmenopausal women, urinary estrone and estradiol were approximately 20% and 40% lower (P trend=0.01 and 0.05, respectively) in women drinking green tea daily compared to those drinking<1 time/week. Adjustment for potential confounders (age at menarche, parity/age at first birth, body mass index, Asian birthplace, soy) did not change these associations. CONCLUSIONS: Findings suggest that intake of green tea may modify estrogen metabolism or conjugation and in this way may influence breast cancer risk.

Pre- and postfortification intake of folate and risk of colorectal cancer in a large prospective cohort study in the United States.

BACKGROUND: A higher folate intake is associated with a decreased colorectal cancer risk in observational studies, but recent evidence suggests that excessive folate supplementation may increase colorectal cancer risk in some individuals. Therefore, mandatory folic acid fortification of grain products in the United States may have unintended negative consequences. OBJECTIVE: We examined the association between folate intake and colorectal cancer risk, including 8.5 y of postfortification follow-up. DESIGN: We examined the association between folate intake and colorectal cancer in the NIH-AARP Diet and Health Study-a US cohort study of 525,488 individuals aged 50-71 y initiated in 1995-1996. Dietary, supplemental, and total folate intakes were calculated for the pre- and postfortification periods (before and after 1 July 1997) based on a baseline food-frequency questionnaire. HRs and 95% CIs were calculated by using multivariable Cox proportional hazards regression models. RESULTS: During follow-up through 31 December 2006 (mean follow-up: 9.1 y), 7212 incident colorectal cancer cases were identified. In the postfortification analysis (6484 cases), a higher total folate intake was associated with a decreased colorectal cancer risk (HR for ≥900 compared with <200 µg/d: 0.70; 95% CI: 0.58, 0.84). The highest intakes specifically from supplements (HR: 0.82; 95% CI: 0.72, 0.92) or from diet (HR: 0.81; 95% CI: 0.67, 0.97) were also protective. The pattern of associations was similar for the prefortification period, and no significant differences between time periods were observed. CONCLUSIONS: In this large prospective cohort study that included 8.5 y of postfortification follow-up, folate intake was associated with a decreased colorectal cancer risk. Given that the adenoma-carcinoma sequence may take ≥10 y, additional follow-up time is needed to fully examine the effect of folic acid fortification.