Breast Cancer

High or prolonged exposure to estrogens has been indicated to be one risk factor for breast cancer. 50 % of all estrogens are excreted in the bile and partly reabsorbed in enterohepatic circulation. By consuming whole grain bread it is possible to reduce the absorption of biliary estrogens and increase the fecal output of these hormones. Furthermore, whole-grain rye bread contains high amounts of lignans which have been shown to reduce breast cancer risk in rodents.

So far only one study has measured rye bread intake and a few studies have reported whole grain intake in relation to breast cancer risk the results not supporting risk lowering effects of whole grains. More information can be gathered from studies reporting fibre intake. In Case-control epidemiologic studies show that a high fibre diet reduces breast cancer risk. However, most prospective studies have not been able to show any fibre effects on risk. Only one prospective study has revealed that cereal fiber is protective in pre-menopausal subjects. On the other hand, in other study significant negative correlations have been found between fibre intake and breast cancer risk.

Rye has several possible mechanisms e.g. high lignan and fibre content, through which it could reduce the risk of breast cancer, but so far the evidence on the effects is still inadequate and more research on the subject is needed to confirm the relation.



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