British Journal of Nutrition

Dietary Surveys and Nutritional Epidemiology

Dietary folate, vitamin B6, vitamin B12 and methionine intake and the risk of breast cancer by oestrogen and progesterone receptor status

Cai-Xia Zhanga1a2, Suzanne C. Hoa1 c1, Yu-Ming Chena2, Fang-Yu Lina3, Jian-Hua Fua4 and Shou-Zhen Chenga3

a1 Centre of Research and Promotion of Women's Health, 4th Floor, School of Public Health and Primary Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin NT, Hong Kong Special Administrative Region, People's Republic of China

a2 Department of Biostatistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, People's Republic of China

a3 Nursing Department, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China

a4 Department of Thoracic Surgery, Sun Yat-sen University Cancer Centre, Guangzhou, People's Republic of China

Abstract

Few studies have evaluated the relationship between the consumption of dietary folate and one-carbon metabolism-related nutrients and breast cancer risk defined by oestrogen receptor (ER) and progesterone receptor (PR) status. The objective of the present study was to examine the associations between dietary folate, vitamin B6, vitamin B12, and methionine intake and the risk of breast cancer by ER and PR status among Chinese women in Guangdong. A hospital-based case–control study was conducted from June 2007 to August 2008, with 438 cases and 438 age (5-year interval)- and residence (rural/urban)-matched controls. Dietary intake information was assessed using a validated FFQ administered through a face-to-face interview. Unconditional logistic regression models were used to calculate multivariate-adjusted OR and 95 % CI. A significant inverse association was found between dietary folate and vitamin B6 intake and breast cancer risk. The adjusted OR of the highest v. the lowest quartile were 0·32 (95 % CI 0·21, 0·49; Ptrend < 0·001) for dietary folate and 0·46 (95 % CI 0·30, 0·69; Ptrend < 0·001) for vitamin B6. No associations were observed for vitamin B12 and methionine intake. A significant inverse association between dietary folate intake and breast cancer risk was observed in all subtypes of ER and PR status. These findings suggest that dietary folate and vitamin B6 intakes were inversely associated with breast cancer risk. The inverse association did not differ by ER and/or PR status.

(Received August 29 2010)

(Revised November 28 2010)

(Accepted February 09 2011)

(Online publication May 16 2011)

Correspondence:

c1 Corresponding author: Professor S. C. Ho, fax +852 26026986, email suzanneho@cuhk.edu.hk

Footnotes

Abbreviations: ER, oestrogen receptor; PR, progesterone receptor