Relationship between Chinese medicine dietary patterns and the incidence of breast cancer in Chinese women in Hong Kong: a retrospective cross-sectional survey

BACKGROUND: This retrospective cross-sectional study aimed to investigate the relationship between Chinese medicine (CM) dietary patterns (hot, neutral, and cold) and the incidence of breast cancer among Chinese women in Hong Kong. METHODS: Breast cancer cases (n = 202) and healthy controls (n = 202) were matched according to demographics. Chinese women residing in Hong Kong for the past 7 years were recruited by media advertisements (e.g., via newspapers, radio, and posters). The control participants were recruited by convenience sampling from health workshops held in clinics and communities of 15 districts of Hong Kong. After completing test–retest reliability, all participants were asked to complete diet pattern questionnaires about their food preferences and dietary patterns. The Student’s unpaired t test, Chi square test, and logistic regression were conducted using SPSS software. RESULTS: Three major CM dietary patterns were identified: hot, neutral, and cold. The participants with breast cancer exhibited a stronger preference for hot food than the control group (Chi square test, P < 0.001). A higher frequency of breast cancer was associated with a higher frequency of dining out for breakfast (4–5 times per week, Chi square test, P = 0.015; 6–7 times per week, Chi square test, P < 0.001) and lunch (4–5 times per week, Chi square test, P < 0.001; 6–7 times per week, Chi square test, P = 0.006). The participants with no history of breast cancer consumed CM supplements and Guangdong soups (1–2 times per week, Chi square test, P = 0.05; >3 times per week, Chi square test, P < 0.001) more frequently than those with breast cancer. CONCLUSIONS: Non-breast cancer participants adopted a neutral (healthy and balanced) dietary pattern, and consumed CM supplements and Guangdong soups more frequently. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13020-017-0138-9) contains supplementary material, which is available to authorized users.