This is going to shock you, but it turns out that repeatedly bashing your head playing football makes you more likely to develop mental problems—a lot more. Ex-NFL players are four times as likely to die of Alzheimer's or ALS (Lou Gehrig's Disease) as other men their age, a new study has discovered. That risk shoots up even higher for players who tended to collide at high speeds, the LA Times reports.
It's the most extensive health study yet on former players, tracking 3,439 retirees. Apart from brain diseases, they were the picture of health; in general, they were half as likely to die at any given age as other men. The study's authors add that it's possible that many deaths attributed to Alzheimer's or ALS were actually driven by chronic traumatic encephalopathy. Autopsies of athlete's brains have revealed protein buildups consistent with CTE. One pathologist involved in those autopsies hailed the study as "groundbreaking." (Read more chronic traumatic encephalopathy stories.)