A potential association between recent increased incidence of breast and uterine body cancers in Japanese women and changes in dietary saturated fat and folate intake: A meta-analysis

Abstract

Recent increases in breast and uterine body cancers among Japanese women suggest the involvement of some modifiable factors in cancer development, including drinking and smoking habits, which are generally associated with Westernized lifestyles. Using national data on annual cancer incidence, this study examines the associations between recent changes in cancer incident rates and dietary habits. Data on age-specific incidence and mortality rates of breast, uterine body, colon, and lung cancers from 2004 to 2019, as well as annual changes in the intake of animal protein, plant protein, saturated fatty acids, and folate from 2001 to 2019 among Japanese women, were obtained from e-Stat, a portal site of Japanese Government Statistics. The analysis indicates that the incidence rates of breast and uterine body cancers among Japanese women increased from 2004 to 2019, displaying distinct distribution patterns with two peaks for breast cancer and one peak for uterine body cancer. The rising incidence rates of both cancers were positively correlated with annual changes in animal protein and saturated fat intake and inversely correlated with changes in plant protein and folate intake. Health-care professionals should be aware of the notable and characteristic increase in breast and uterine body cancer incidence among Japanese women and emphasize the importance of lifestyle modifications to counteract Westernized dietary habits.