Los Angeles ? A stiffening of the aging brain’s blood vessels reduces their ability to respond to changes in blood pressure, increasing the risk of falls by as much as 70 percent, researchers reported Monday.

Although the change in the arteries is only one of many factors that lead to falls among the elderly, the findings provide a potential target for intervention, said Dr. Joe Verghese, a neurologist at Albert Einstein University College of Medicine who was not involved in the research. Treating high cholesterol, high blood pressure and diabetes, among other factors, can reduce the stiffening.

“Even if it accounts for only 10 percent to 15 percent of all falls, that’s still large numbers that you are talking about,” he said.

According to the Centers for Disease Control and Prevention, more than a third of adults over the age of 65 fall each year, and 30 percent of those suffer moderate to severe injuries, including hip fractures and traumatic brain injuries. Most elderly who are hospitalized with a hip fracture end up in a nursing home.

A variety of factors have been linked to falls, including diseases, foot problems, overmedication, environmental hazards — and abnormalities in the signaling potential of the brain’s white matter, which controls both cognitive and motor functions, have also been linked. The new study was designed to demonstrate at least one mechanism by which these latter abnormalities could occur.

Dr. Farzaneh A. Sorond, a neurologist at Harvard University’s Institute for Aging Research, and her colleagues studied 420 people over the age of 65.

The study was funded by the National Institute on Aging and a private donor.