Daniel Daneshvar

Researchers looked at the brains donated by 235 families for the study, and 215 of those brains showed signs of CTE.

Now, we need to bear in mind that as lead author Dr. Daniel Daneshvar from Harvard Medical School says, families are more likely to donate a brain when they've already noticed memory issues, mood changes, or behavioral changes while the person was alive, which can skew the numbers.

Even so, Dr. Daneshvar says the possible rate of CTE among NFL players is very concerning, pointing out that less than 1% of the general non-athlete population develops this kind of brain damage.

And the bit that is really scary for us all, the majority of these players' head knocks didn't happen during major league games, but instead in their early years, from junior sporting into high school and at university.

Yeah.

Said Dr. Daniel Daneshvar, the study's lead author.

The study found the maximum possible prevalence of CTE was around 97%, but the true rate is somewhere in the middle.

Yeah.

A quarter, so, like, one in four.

Yep, and the study's lead author, a doctor named Daniel Daneshvar, who directs a brain function lab at Mass General Brigham, says that number is the low end.

Counting only the cases of CTE that we diagnosed ourselves, we found the minimum rate of CTE between 2016 and 2021 was 25%.

At the upper end, the maximum rate of CTE was 98%, and so the true rate of CTE at death is somewhere in the middle there.

I mean, that's actually really the whole thing with CTE research, and I've written about so many CTE studies where I make that point in the story of, like, look, there's sample bias because 93% of all these NFL player samples in this brain bank have CTE, but you can't draw too many conclusions from that for exactly the reason you say.

And so that, of course, was on the mind of the authors of this survey, this study that we're talking about.

Here again is lead author Dr. Daniel Daneshvar.

And so whenever we look at the percent or the rate of neurodegenerative disease in specific brain bank populations, we know that it's not presenting an accurate picture of what's really going on with the overall population or sample.

They just wanna know straight up, "If my kid plays football, what is the likelihood they will suffer for the rest of their lives?" Well, yesterday, researchers published a study in the British Medical Journal making a startling claim that between the years 2016 and 2021, of all the former NFL players who died those years, one in four of them had CTE.

Let's start the day with Dr. Daniel Daneshvar.

He's the chief of brain injury rehabilitation at Harvard Medical School.

He's the co-director of the Sports Concussion Program at Mass General Brigham.

... that are specific to this type of process later in life.

Really useful.

Uh, Dr. Daniel Daneshvar, uh, from Harvard a- and Mass General, also a member of BU's renowned, uh, CTE center, thank you so much.

Thank you very much for having me.