Dietary intake and plasma levels of folate, vitamins B6 and B12 and breast cancer risk: A case-control study

• Main Authors: Huang, Hsin-Ping, 黃心萍
• Other Authors: Sun, Chien-An
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/37930388840165772703

碩士 === 國防醫學院 === 公共衛生學研究所 === 96 === Folate is an important co-factor in one-carbon metabolism, which is important for purine synthesis, DNA repair and DNA methylation. In the past, there were no studies examining intake data and plasma levels at the same time when evaluate the relationships of folate, vitamins B6 and B12 with the risk of breast cancer. Therefore, we conducted this study to examine the relationships of dietary folate intake and plasma folate levels with the risk of breast cancer. In addition, we evaluated whether vitamins B6 and B12 intake and plasma levels were modified the effects of dietary intake and plasma levels of folate on breast cancer risk. This case-control study included 300 patients with incident breast cancer cases and 300 healthy controls, which matched by age (±5 years) and fasting status (±4 hours) with cases. Risk factors and dietary habits were assessed with an interviewer-administered risk questionnaire and a semi-quantitative questionnaire, and an amount of 10c.c whole blood was collected. Conditional logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). The results showed that total folate intake was inversely associated with breast cancer risk with an adjusted OR of 0.54 (95% CI= 0.32–0.90) when women who were in the highest quartile of intake was compared with those in the lowest quartile of intake. In addition, total vitamin B6 intake was inversely associated with breast cancer risk with an adjusted OR of 0.57 (95% CI= 0.35–0.92) when women who were in the highest quartile of intake was compared to those in the lowest quartile of intake. Whereas, total vitamin B12 intake was not statistically significantly associated with breast cancer risk. When these three B-vitamin nutrients considered simultaneously, women who were in the lowest quartile intake of the B-vitamins had 86% increased risk of breast cancer (adjusted OR=1.86, 95% CI=1.05-3.29) as compared with those who were in the highest quartile of intake. Results from data on plasma levels showed similar findings as obtained from dietary data. In conclusion, total folate intake and plasma folate levels were inversely associated with breast cancer risk. Of particular note, studies assessing the effect of folate on breast cancer risk should take into consideration of co-factors involved in folate metabolism (i.e. vitamins B6 and B12).