other risk factors like this gene,” he said. Lipton noted that about 25% of the population carries the APOE e4 allele.
Lipton said the injuries to the brain from heading aren’t concussions, but rather tiny subclinical damage that doesn’t produce obvious symptoms.
Excessive heading is hitting the ball with the head at least 1,000 times in a year. That may seem like a lot, but Lipton’s team found that some players headed the ball in the range of 15,000 times a year.
For the report, Lipton and his colleagues studied nearly 380 amateur soccer players who took part in a soccer study from November 2013 through January 2018. Among these players, 355 had their genes sequenced to look for the APOE e4 allele.
All the players had played soccer for five years or more, and over several visits to the clinic, they took memory tests and estimated how many times they had headed the ball. In all, 352 players with a total of more than 1,200 test sessions were analyzed.
According to Lipton, many of the consequences of heading for those who carry the APOE e4 allele aren’t known. For example, it’s not known whether
