Tea Drinking as a Risk Factor for Neural Tube Defects in Northern China

• Published in: Epidemiology (Cambridge, Mass.) Mass.), 2011-07, Vol.22 (4), p.491-496
• Main Authors: Ye, Rongwei, Ren, Aiguo, Zhang, Le, Li, Zhiwen, Liu, Jianmeng, Pei, Lijun, Zheng, Xiaoying
• Format: Article
• Language: English
• Subjects: Adult; Anencephaly; Biological and medical sciences; Case-Control Studies; China - epidemiology; Dietary Supplements; Diseases of the osteoarticular system; Diseases of the spine; Drinking Behavior; Encephalocele; Epidemiology; Female; Folic Acid; General aspects; Green teas; Humans; Infant, Newborn; Maternal age; Medical sciences; Miscellaneous; Neonatal disorders; Neural tube defects; Neural Tube Defects - epidemiology; Odds Ratio; Population Surveillance; Pregnancy; Public health. Hygiene; Public health. Hygiene-occupational medicine; REPRODUCTIVE; Risk Factors; Spina bifida; Surveys and Questionnaires; Tea; Tea - adverse effects
• ISSN: 1044-3983; 1531-5487
• DOI: 10.1097/EDE.0b013e31821b4526

Background: Tea catechins inhibit the activity of the enzyme dihydrofolate reductase, which catalyzes the inactive form of folate 7,8-dihydrofolate to the active form of folate 5,6,7,8-tetrahydrofolate. This inhibition leads to disturbance of the folate metabolic pathway and to lower bioavailability of folate to cells; therefore, it may increase the risk of neural tube defects (NTDs) in a developing embryo. We examined the association between tea drinking during the periconceptional period and the risk of NTDs. Methods: Cases were fetuses or neonates with an NTD as ascertained through a population-based surveillance system in 4 rural counties of Shanxi Province in northern China during 2002 through 2007. Controls were term infants without congenital malformations. Demographic, reproductive, and exposure data were obtained through a face-to-face interview. Results: A total of 631 NTD cases and 857 controls were included in the analysis. Compared with women who did not drink tea during the periconceptional period (487 cases and 688 controls), women who drank tea daily (20 cases and 9 controls) had a 3-fold increased risk (odds ratio = 3.1 [95% confidence interval = 1.4—7.0]) of having an NTD-affected pregnancy. The elevated risk associated with daily tea drinking remained after adjusting for maternal age, educational level, occupation, and periconceptional folic acid supplementation (3.4 [1.4—8.3]). The association was present for all 3 major subtypes of NTDs (ie, anencephaly, spina bifida, and encephalocele). Conclusions: Daily tea drinking during the periconceptional period was associated with an elevated risk of NTDs in this Chinese population.