Study: Consuming processed meats can increase risk of breast cancer
Breast cancer risks increased by 21% in women who consumed more than 9 g of processed meat per day, according to a study published in The European Journal of Cancer. The study looked at the consumption of both processed meat and red meat but found that red meat was not associated with breast cancer.
The researchers used data from the UK Biobank, an ongoing general population cohort study, which recruited participants aged 40 to 69 (n = 500 000 adults). Breast cancer incidence was determined through cross-referencing routine hospital admission, cancer registry, and death certificate data. Once the study population had been set, the researchers used univariate data and multivariable Cox proportional hazard models to explore any link between red meat, processed meat (red meat that has been salted, cured, fermented, smoked or undergone other processes), and breast cancer. Additionally, the researchers performed a meta-analysis using a random effects model of published cohort studies to expand the study.
The study identified 262,195 women aged 40 to 69s from the UK Biobank study. Of them women, 4,819 women (1.84%) were diagnosed with breast cancer over a median of 7 years of follow-up. Risk of breast cancer was increased in the highest tertile (> 9 g/day) of processed meat consumption (adjusted hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.08-1.35, P = 0.001). After accounting for other dietary factors, as well as sociodemographic factors and weight, the findings from the UK Biobank data still remained significant. Collation with 10 previous cohort studies returned data on 40,257 (2.44%) incident breast cancers out of 1.65 million women. Once again, processed meat consumption was associated with overall (relative risk [RR] 1.06, 95% CI 1.01-1.11) and postmenopausal (RR 1.09, 95% CI 1.03-1.15), but not premenopausal (RR 0.99, 95% CI 0.88-1.10) breast cancer. Red meat consumption was not associated with breast cancer in either the UK Biobank or the meta-analysis (adjusted HR 0.99, 95% CI 0.88-1.12 and RR 1.03, 95% CI 0.99-1.08, respectively).
The authors noted some limitations of the study. The data from the UK Biobank study were not a representative sample of the UK population since women participating in the study were generally wealthier and healthier. The data are also reliant on the participants accurately reporting how much processed meat they ate. In addition, while the UK Biobank study data accounted for dietary factors, not all of the studies included in the meta-analysis did. Ultimately, the authors suggest that more research is needed, but the findings were significant enough that physicians should educate their patients, especially women who are postmenopausal, about the correlation between intake of processed meat and breast cancer risk.