Is breast cancer avoidable? Could dietary changes help?

Abstract

In the US, the life time odds of developing breast cancer has reached one in eight, with an incidence rate of 85 per 100000 world population. The rate is half or less in women in some Mediterranean countries. At the extreme are rural African women whose rate is approximately 5–10 per 100000. In African, compared with White women, protective factors include (1) reproductive behaviour, namely, slower growth before and after puberty, later age at menarche, high teenage pregnancy, high parity and long periods of lactation and amenorrhoea and (2) a diet of relatively low energy intake and of low-fat and high-fibre contents. In the Mediterranean setting, major dietary protective factors include a relatively low intake of saturated fat and high intakes of monounsaturated fat and of vegetables and fruit. Among White women, a reversion to protective reproductive behaviour is out of the question. Only in respect of diet, could significant avoiding action be taken. Adoption of an African type diet is wholly impracticable. Moreover, even conformation to a former Mediterranean diet, which is already changing, would be difficult, requiring reorientation of fat composition and large rises in intakes of vegetable and fruit. However, with resolution, were such changes made, at least by the very vulnerable, they would help, additionally, to protect against other diet-related cancers, especially colon cancer and against coronary heart disease.