Good cholesterol.

Wait, which one is good again? 27-hydroxycholesterol is an endogenous selective estrogen receptor modulator (SERM) and has been linked to growth of hormone-receptor positive breast cancers in preclinical studies. Ok, so this one’s bad...right? Not according to this case-control study of the Heidelberg EPIC cohort, in which baseline serum levels of 27-HC were compared among women who either did or did not go on to develop breast cancer. Overall, there was no association between 27-HC levels and development of breast cancer. More confusingly, among post-menopausal women, higher levels of 27-HC were associated with a lower risk of developing breast cancer. While this still doesn’t make much sense, at least it's consistently confusing. TBL: 27-HC is an endogenous SERM, but it may (somehow) be modulating the estrogen receptor for the better. | Lu, JNCI 2018