Alcohol and dietary folate intake and the risk of breast cancer

Abstract

Owing to its interaction with alcohol, folate has been suggested to be a potential factor for many types of cancer. The impact of these factors on the risk of breast cancer among Asian populations has not been fully examined, however, particularly with respect to receptor status. We carried out a case-control study in premenopausal and postmenopausal Japanese women, including 1754 breast cancer patients and 3508 noncancer controls. We determined the association between self-reported alcohol drinking, dietary folate intake, and the risk of breast cancer. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using logistic models adjusted for potential confounders. Alcohol consumption was associated with the risk of breast cancer, with the OR for a drinker consuming 23 g or more per day relative to a nondrinker of 1.39 (95% CI: 1.07-1.80). A significant inverse association was observed between folate intake and overall risk of breast cancer, with an OR of 0.79 (95% CI: 0.68-0.93; Ptrend=0.004) for the highest tertile relative to the lowest. The OR of a drinker consuming 23 g or more per day relative to a nondrinker with a low folate intake was 1.58 (95% CI: 1.06-2.33). However, a significantly increased risk was not observed in tertile 2 and tertile 3 folate in taker with any amount of alcohol consumption. Higher folate intake decreases the risk of breast cancer among Japanese, whereas alcohol intake increases the risk. These two factors interact with each other, and the excess risk of breast cancer with alcohol consumption might be attenuated by increasing the intake of folate. In addition, the effects of folate/alcohol may vary according to the tumor subtype.

Association of dietary intake of folate and MTHFR genotype with breast cancer risk

“…Although increased folate intake may be good for a population deficient in this nutrient, increased intake in women with already-sufficient levels of folate may provide no further benefit or actually be harmful. Several previous studies did not report a significant association with breast cancer risk (Vaĭner et al, 2010;Islam et al, 2013;, which is in line with our results. The results indicated that folate intake could not play a protective role in breast cancer for women who had a nutritional deficiency.…”

“…Low dietary folate intake has been associated with risk of various cancers, such as colorectal cancer, pancreatic cancer, prostate cancer and gastric cancer (Bassett et al, 2013;Lin et al, 2013;Collin, 2013;Gao et al, 2013). Recently, several studies reported a protective effect of folate intake on breast cancer risk Yang et al, 2013;Islam et al, 2013). However, evidence from two recent studies have indicated an inverse association (Ericson et al, 2007;Maruti et al, 2009a), and some other studies have shown that the reduced risk only exists in certain populations, such as women with high levels of alcohol intake or premenopausal Chinese women (Levi et al, 2001;Shrubsole et al, 2011).…”

Association between dietary intake of folate and MTHFR and MTR genotype with risk of breast cancer

“…It has been reported that high intake of folate is beneficial to women who are deficient in nutrient gain. Several previous studies have reported inconsistent results for folate intake and breast cancer risk (Ma et al, 2009;Wu et al, 2012;Tavani et al, 2012;Islam et al, 2013;Qin et al, 2013; Yang et al, 2013). In our study, we reported that folate intake does not play a protective role in breast cancer risk in Chinese population.…”

Association of Dietary Intake of Folate, Vitamin B6and B12and MTHFR Genotype with Breast Cancer Risk

“…Although increased folate intake may be good for population deficient in this nutrient, increased intake in women with already-sufficient levels of folate may provide no further benefit or actually harmful. Previous several studies did not report a significant association with breast cancer risk (Vaĭner et al, 2010;Islam et al, 2013), which is in line with our results. The results indicated folate intake could not play a protective role in breast cancer for women who already have deficient in nutrition.…”