Birth control pill linked to reduced knee injury

Women who take the birth control pill, which lessens and stabilises estrogen levels, are less likely to suffer serious knee injuries, suggests new research.

Using a database of 23,428 young women between ages 15 and 19, the study found that women with an anterior cruciate ligament (ACL) knee injury who were taking the birth control pill were less likely to need corrective surgery than women of the same age with ACL injuries who do not use the birth control pill.

"Birth control pills help maintain lower and more consistent levels of estrogen, which may prevent periodic ACL weakness," said lead author of the study Aaron Gray from The University of Texas Medical Branch at Galveston, US.

The ACL is a ligament that connects the top and bottom portions of the knee. Damage to this ligament is a serious athletic injury that can be career altering. Also, this injury may lead to lifelong issues with knee instability, altered walking gait and early onset arthritis.

"With this in mind, we examined whether oral contraceptive use protected against ACL injuries that require surgery in women," Gray noted.

The findings appeared in the journal Medicine & Science in Sports & Exercise.

The study led the researchers to propose that the female hormone estrogen makes women more vulnerable to ACL injury by weakening this ligament.

"Young athletes currently use birth control pills for various reasons including more predictable cycles and lighter periods," Gray said.

"Injury risk reduction could potentially be added to that list with further, prospective investigations," Gray added.