Dairy consumption and risks of total and site-specific cancers in Chinese adults: an 11-year prospective study of 0.5 million people

Abstract

Background Previous studies of primarily Western populations have reported contrasting associations of dairy consumption with certain cancers, including a positive association with prostate cancer and inverse associations with colorectal and premenopausal breast cancers. However, there are limited data from China where cancer rates and levels of dairy consumption differ importantly from those in Western populations. Methods The prospective China Kadoorie Biobank study recruited ~0.5 million adults from ten diverse (five urban, five rural) areas across China during 2004–2008. Consumption frequency of major food groups, including dairy products, was collected at baseline and subsequent resurveys, using a validated interviewer-administered laptop-based food frequency questionnaire. To quantify the linear association of dairy intake and cancer risk and to account for regression dilution bias, the mean usual consumption amount for each baseline group was estimated via combining the consumption level at both baseline and the second resurvey. During a mean follow-up of 10.8 (SD 2.0) years, 29,277 incident cancer cases were recorded among the 510,146 participants who were free of cancer at baseline. Cox regression analyses for incident cancers associated with usual dairy intake were stratified by age-at-risk, sex and region and adjusted for cancer family history, education, income, alcohol intake, smoking, physical activity, soy and fresh fruit intake, and body mass index. Results Overall, 20.4% of participants reported consuming dairy products (mainly milk) regularly (i.e. ≥1 day/week), with the estimated mean consumption of 80.8 g/day among regular consumers and of 37.9 g/day among all participants. There were significant positive associations of dairy consumption with risks of total and certain site-specific cancers, with adjusted HRs per 50 g/day usual consumption being 1.07 (95% CI 1.04–1.10), 1.12 (1.02–1.22), 1.19 (1.01–1.41) and 1.17 (1.07–1.29) for total cancer, liver cancer (n = 3191), female breast cancer (n = 2582) and lymphoma (n=915), respectively. However, the association with lymphoma was not statistically significant after correcting for multiple testing. No significant associations were observed for colorectal cancer (n = 3350, 1.08 [1.00–1.17]) or other site-specific cancers. Conclusion Among Chinese adults who had relatively lower dairy consumption than Western populations, higher dairy intake was associated with higher risks of liver cancer, female breast cancer and, possibly, lymphoma.

Association between Dairy Consumption and Psychological Symptoms: Evidence from a Cross-Sectional Study of College Students in the Yangtze River Delta Region of China

“…The proportion of dairy consumption among Chinese college students is higher than that of Chinese adults, and much lower than that of European and American countries. The results showed that 20.4% of Chinese adults consume dairy products at least once a week, and 68.5% of respondents reported they never or rarely consume dairy products [ 28 ]. Among college students in Azorean, 91.8% of female students and 98.8% of male students were reported to consume at least one serving of dairy products between two and four times per week [ 26 ].…”

Comparison and recommendation of dietary patterns based on nutrients for Eastern and Western patients with inflammatory bowel disease

“…However, some studies have shown that the overall risk of cancer is increased by 9% in people who regularly consume dairy products. The risk of liver and breast cancer is significantly increased in people who frequently consume dairy products, with an additional intake of 50 grams per day increasing the risk by 12% and 17%, respectively ( 99 ). Accordingly, dairy products should not be consumed in excess.…”

Short-term serum and urinary changes in sex hormones of healthy pre-pubertal children after the consumption of commercially available whole milk powder: a randomized, two-level, controlled-intervention trial in China

“…11 The latest results of the prospective China Kadoorie Biobank study showed that dairy consumption is positively associated with risks of total cancer, liver cancer, and female breast cancer in Chinese adults with the adjusted hazard ratios per 50 g day −1 usual consumption being 1.07 (95% CI 1.04–1.10), 1.12 (1.02–1.22), and 1.19 (1.01–1.41), respectively. 12 More importantly, a population-based cohort study in Iceland with a 24.3-year follow-up reported a positive correlation between milk consumption in adolescence and prostate cancer. 13 The endogenous sex hormone levels are low in children, 14 and pre-pubertal children's hypothalamus–pituitary–genital axis (HPG) is particularly sensitive to exogenous sex hormones.…”

“…19 (1.01-1.41), respectively. 12 More importantly, a populationbased cohort study in Iceland with a 24.3-year follow-up reported a positive correlation between milk consumption in adolescence and prostate cancer. 13 The endogenous sex hormone levels are low in children, 14 and pre-pubertal children's hypothalamus-pituitary-genital axis (HPG) is particularly sensitive to exogenous sex hormones.…”