Estrogen found to help protect women from cardiovascular disease.

Oestrogen hormone could help protect women from cardiovascular disease by keeping the body's immune system in check. New research from Queen Mary, University in London published in the American Heart Association journal Arteriosclerosis, Thrombosis and Vascular Biology.

The hormone oestrogen is a variant of female sex hormones that are secreted in the ovary and responsible for female sexual characteristics.

Researchers have found that oestrogen works on white blood cells to stop them from sticking to the insides of the blood vessels, a process that can lead to vessel blockages. The results could explain why cardiovascular disease rates tend to go up in women after menopause.

Researchers compared white blood cells in men and premenopausal women blood donors and found that cells from premenopausal women have higher levels of protein annexin-A1 in the surface of the white blood cells. The Annexin-A1 prevents white blood cells from sticking to the blood vessels.

The new research shows that oestrogen can move annexin-A1 from inside the white blood cell, where it is normally stored, to the surface of the cells, thereby preventing the cells from sticking to blood vessel walls and causing vascular damage. This may have important implications in cardiovascular disease.

"We've known for a long time that oestrogen protects pre-menopausal women from heart disease, but we don't know exactly why. This study brings us a step closer to understanding how natural oestrogen might help protect our blood vessels said Dr. Suchita Nadkarni from the William Harvey Research Institute, Queen Mary, University of London, who led the research.

“Our results suggest that oestrogen helps maintain the delicate balance between fighting infections, and protecting arteries from damage that can lead to cardiovascular disease” said Nadkarni.