There has been a hypothesis that a diet high in fiber can reduce future risk of breast cancer by inhibiting estrogen reabsorption. One meta-analysis has shown a weak effect that eating fiber reduces breast cancer risk . However, other studies, including the Nurses’ Health Study, did not show this association . It is also known that factors in childhood and early adult life can affect future breast cancer risk. A recently published study has analyzed data from the Nurses’ Health II Study which allowed analysis of fiber intake during adolescence or early adulthood (which is a younger age range than other studies) for a longer follow-up time than other studies .
This study analyzed questionnaires from over 44,000 women which documented information about their diet and alcohol intake during high school. There was also an evaluation of the influence of adjustment for alternate healthy-eating index score as well as red meat, animal fat, or β-carotene, as these can also affect future breast cancer risk. Their results demonstrated that, among all women, total fiber intake in early adulthood was associated with significantly lower breast cancer risk. Each 10 g/day increase in total fiber intake during early adulthood was associated with a 13% decrease in breast cancer risk among all women (relative risk 0.87; 95% confidence interval 0.80–0.95). There was a stronger association for premenopausal breast cancer than for postmenopausal breast cancer, although this was not significant.
Louise R. Newson
Solihull, West Midlands, UK
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