Search

Background: Epidemiologic evidence regarding niacin, folate, vitamin B-6, and vitamin B-12 intake in relation to cognitive function is limited, especially in midlife. Objective: We hypothesize that higher intake of these B vitamins in young adulthood is associated with better cognition later in life. Design: This study comprised a community-based multicenter cohort of black and white men and women aged 18-30 y in 1985-1986 (year 0, i.e., baseline) from the Coronary Artery Risk Development in Young Adults (CARDIA) study ( n = 3136). We examined participants' CARDIA diet history at years 0, 7, and 20 to assess nutrient intake, including dietary and supplemental B vitamins. We measured cognitive function at year 25 (mean ± SD age: 50 ± 4 y) through the use of the Rey Auditory Verbal Learning Test (RAVLT) for verbal memory, the Digit Symbol Substitution Test (DSST) for psychomotor speed, and a modified Stroop interference test for executive function. Higher RAVLT and DSST scores and a lower Stroop score indicated better cognitive function. We used multivariable-adjusted linear regressions to estimate mean differences in cognitive scores and 95% CIs. Results: Comparing the highest quintile with the lowest (quintile 5 compared with quintile 1), cumulative total intake of niacin was significantly associated with 3.92 more digits on the DSST (95% CI: 2.28, 5.55; P -trend < 0.01) and 1.89 points lower interference score on the Stroop test (95% CI: -3.10, -0.68; P -trend = 0.05). Total folate was associated with 2.56 more digits on the DSST (95% CI: 0.82, 4.31; P -trend = 0.01). We also found that higher intakes of vitamin B-6 (quartile 5 compared with quartile 1: 2.62; 95% CI: 0.97, 4.28; P -trend = 0.02) and vitamin B-12 (quartile 5 compared with quartile 1: 2.08; 95% CI: 0.52, 3.65; P -trend = 0.02) resulted in better psychomotor speed measured by DSST scores. Conclusion: Higher intake of B vitamins throughout young adulthood was associated with better cognitive function in midlife., (© 2017 American Society for Nutrition.)

Background: The role of one-carbon metabolism nutrients in colorectal carcinogenesis is not fully understood. Associations might be modified by mandated folic acid (FA) fortification or alcohol intake., Objective: We investigated associations between intakes of folate, riboflavin, vitamin B-6, and vitamin B-12 and colorectal cancer (CRC) in the Women's Health Initiative Observational Study, stratified by time exposed to FA fortification and alcohol intake., Design: A total of 88,045 postmenopausal women were recruited during 1993-1998; 1003 incident CRC cases were ascertained as of 2009. Quartiles of dietary intakes were compared; HRs and 95% CIs were estimated by Cox proportional hazards models., Results: Dietary and total intakes of vitamin B-6 in quartile 4 compared with quartile 1 (HR: 0.80; 95% CI: 0.66, 0.97 and HR: 0.80; 95% CI: 0.66, 0.99, respectively) and total intakes of riboflavin (HR: 0.81; 95% CI: 0.66, 0.99) were associated with reduced risk of CRC overall and of regionally spread disease. In current drinkers who consumed <1 drink (13 g alcohol)/wk, B vitamin intakes were inversely associated with CRC risk (P-interaction < 0.05). Dietary folate intake was positively associated with CRC risk among women who had experienced the initiation of FA fortification for 3 to <9 y (P-interaction < 0.01)., Conclusions: Vitamin B-6 and riboflavin intakes from diet and supplements were associated with a decreased risk of CRC in postmenopausal women. Associations of B vitamin intake were particularly strong for regional disease and among women drinkers who consumed alcohol infrequently. Our study provides new evidence that the increased folate intake during the early postfortification period may have been associated with a transient increase in CRC risk.