"Heading" a soccer ball frequently can lead to brain injury and cognitive impairment, according to a study from the Albert Einstein College of Medicine at Yeshiva University.

Researchers identified five areas in the brain that were affected by frequent heading which are responsible for attention, memory, executive functioning and higher-order visual functions, according to statement.

They also found that players with the highest annual heading frequency performed worse on tests of verbal memory and psychomotor speed.

"Heading a soccer ball is not an impact of a magnitude that will lacerate nerve fibers in the brain," said lead author Michael Lipton. "But repetitive heading may set off a cascade of responses that can lead to degeneration of brain cells."

Scientists went a step further, determining the level of headings that are unsafe for players. They said that if players exceed around 1,000 to 1,500 headings per year -that is around 19 to 28 headings per week- it can result in significant injury to their brains.

The researchers said their findings were important because of the popularity of the sport among children. They noted that of the 18 million Americans who play soccer, 78 percent are under 18-years-old.

"These are findings that should be taken into consideration in planning future research to develop approaches to protect soccer players," Dr. Lipton said.

For the study, researchers used an advance magnetic resonance imaging technique on 38 amateur soccer players on average 30 years old who had played soccer since childhood.

They were asked to recall the number of times they headed the ball during the past year. Then researchers ranked the players based on heading frequency and then compared the brain images of the most frequent headers with those of the remaining players.

They found that frequent headers showed brain injury similar to that seen in patients with concussion, also known as mild traumatic brain injury (TBI).