Implication of milk and dairy products consumption through insulin-like growth factor-I in induction of breast cancer risk factors in women

Abstract

Several studies have evaluated the link between diet and breast cancer in women. This link receives increasing attention from scientists, and many reports have examined the implication of milk and dairy products in the development this disease. Indeed, the available evidence shows that milk increases circulating levels of a mitogenic hormone: insulin-like growth factor-I (IGF-I), and this may affect breast cancer risk. However, epidemiological studies were unsuccessful to establish a strong relationship between this food and the disease. Many other studies measured the role of dairy products in the development of breast cancer risk factors, and our review tried to examine these associations. Our investigation suggests that milk increases appearance of greater adult-attained height, early menarche, delayed menopause and higher birth weight which are all considered as breast cancer risk factors and associated to higher levels of IGF-I. The relationship with adult weight and breast density is still not clear and inconsistent. Our hypothesis suggests that milk intake may influence breast cancer, through some breast cancer risk factors, and IGF-I has an important role in this relationship, but the association with other dairy products is less certain. That is why we suggest that women should consume dairy products other than milk to prevent breast cancer risk.