London, Nov 14 (IANS): Estrogens, also referred to as female sex hormones, have been thought to protect women from heart diseases and researchers have now found how they do so.

An estrogen receptor, previously shown to regulate blood pressure in women, also plays an important role in regulating levels of low-density lipoprotein (LDL) cholesterol, also known as bad cholesterol that drives the process that leads to heart disease, the findings showed.

"This is a really important finding because there has always been some indication that estrogen was protective in lowering cholesterol, but we did not understand how," said Ross Feldman from Western University in Canada.

"The mechanism of estrogen's effect was kind of a black box because we didn't know the receptors responsible for doing it," Feldman added.

The findings could help explain why post-menopausal women with lower levels of estrogen are more likely to have multiple risk factors for heart disease.

The study looked at two populations of women in Canada.

The researchers showed that the G-protein coupled estrogen receptor 30 (GPER) when activated by estrogen helps lower LDL cholesterol levels in the blood by inhibiting the protein PCSK-9.

This finding provides evidence that the hormone estrogen plays a key role in regulating two of the most common risk factors for heart disease and stroke.

The study is forthcoming in the journal Arteriosclerosis, Thrombosis and Vascular Biology.