A new study strengthens suspicions that the female hormone estrogen protects against death from COVID-19.
Researchers in Sweden studied 14,685 older women with COVID-19, all of whom were past menopause, during which estrogen levels decline dramatically.
Seventeen percent were taking estrogen supplements to relieve menopausal symptoms.
After adjusting for other risk factors, women getting extra estrogen had a 53% lower risk of dying from COVID-19 compared to untreated women, the researchers reported this week in BMJ Open https://bmjopen.bmj.com/content/12/2/e053032.
Observational studies such as this one cannot prove higher estrogen levels are protective.
Furthermore, the women were infected before vaccines were available, said Dr. Malin Sund of Umea University.
“Vaccination has clearly been shown to protect from COVID-19 related mortality and the potential added value from estrogen (in vaccinated women) cannot be estimated from this data,” Sund said.
The idea that estrogen might be protective in hospitalized COVID-19 patients is now being tested more rigorously in a randomized controlled trial at Tulane University.