It has long been observed that sluggish thyroid problems are associated with an increased risk for breast cancer, whereas hyperthyroid proneness is associated with lower risk. Previous research has thought this may be due to iodine or selenium deficiency, though a clear link has never been established.
New research proposes overactive thyroid1 is protective against breast cancer because of the extra free radicals the condition generates that induce cell death in breast cancer cells. Conversely, a sluggish thyroid would have less ability to exert such influence on cancer cells, thus the higher rate of breast cancer.
Thyroid hormone controls the rate your body uses oxygen, which does indeed have oxidative or free radical generating properties. While the precise mechanism linking breast cancer and sluggish thyroid remains to be elucidated, it is quite clear that every woman should make it a priority to keep her thyroid function in good working order.


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