Meat intake and breast cancer risk from the Health Examinees study.

The association between meat intake and breast cancer risk remains unclear. This study examined the relationship between specific types of meat intake and breast cancer risk in a prospective cohort study. This study included 71,264 women aged 40-69 years from the Health Examinees-Gem (HEXA-G) study (2004-2013). Cancer diagnosis was identified via the Korea Central Cancer Registry and death certificate-linked data were provided by the Korea National Statistical Office until 31 December 2018. Cox proportional hazards models were used to estimated multivariate hazard ratios (HRs) and 95 % confidence intervals (CIs) for breast cancer risk by meat intake. During 655,566.9 person-years of follow-up, 713 breast cancer cases were identified. Women who consumed one or more servings of processed meat per week had a 57 % increased risk of breast cancer (HR = 1.57, 95 % CI: 1.09-2.27, p for trend = 0.003), compared to those who did not consume processed meat. Stronger associations were observed among women under 50 years of age (p for trend = 0.021), with no family history of breast cancer (p for trend = 0.001), no regular exercise (p for trend = 0.028), no alcohol consumption (p for trend = 0.002) and a body mass index (BMI) below 25 kg/m2 (p for trend = 0.005). Beef intake was associated with a potential reduction in breast cancer risk (HR = 0.82, 95 % CI: 0.67-1.01, p trend = 0.051, for 2 or more servings per month vs. none). Also, reduction of breast cancer risk was observed in women who consumed alcohol (p for trend = 0.036). More pronounced associations were found in women without family history of breast cancer (p for trend = 0.049), and in women who did not engage in regular exercise (p for trend = 0.015). Our results suggest that processed meat intake is linked to a higher risk of breast cancer, whereas beef consumption may reduce the risk of breast cancer.