It's Tuesday, March eight. I'm Oscar Emiras from the Daily Dive podcast in Los Angeles, and this is reopening America. A new study looking at brain scans of people before and after contracting COVID shows that they had more loss of gray matter and tissue damage than those who did not get infected. Notably, the study looked at those that were older and had more mild infections, meaning they did not have to go to the hospital. The shrinkage and
damage was primarily an areas associated with smell. Pambelic, health and science writer at The New York Times joins us for more. Thanks for joining us, Pam, So I'm happy to join you. Well, I wanted to talk about an interesting thing that is COVID related. And this is not to raise any alarms. This is all uh interesting, an interesting study, but there's a lot more questions. Really they
needs to be answered for this. But we're looking at brain scans of people before and after COVID infection and some of them are showing more loss of gray matter and tissue damage than in those that didn't have COVID, and particularly in the area that is around around smell, which kind of tracks with you know a lot of people that lost their sense of smell and taste when they got infected. But Pam, tell us what we're seeing in this study, Yeah, exactly. I think you characterized it
exactly right. It's a really interesting study because it appears to be the first time that researchers have had access to brain scans of people before they got COVID and then about three years later they had scans of these same people and some of those people had COVID in between. So this is medical information that comes from a huge sort of treasure trove of medical records in the United Kingdom. It's called the UK Biobank, and they have medical records
of lots and lots of people. And what they did is they focused on almost eight hundred people and and they were able to see about four hundred of them had got COVID, and so they had these before scans of their brain and then they had an after scan about four and a half months after they had their
COVID infection. So they were looking at this to see did anything change in their brain, And what they found is that the people who had COVID lost more gray matter than the people who didn't so normal aging, we naturally lose a little bit of gray matter in our brains every year, tiny percentage, and the patients who had COVID ended up losing significantly more sad up to more. It's not huge, but in terms of sort of brain volume,
it's significant. And as you said, most of the areas where they noticed this change, we're in brain areas related to sense of smell, which kind of makes sense. But because it's the brain and there's so much overlap in the brain and almost everything in the brain has like multiple functions, some of these areas also have other brain functions related to memory and things like that, so it
raises questions about, like, what does this mean. The typical brain loss was about point two to point three percent annually, and yeah, these people went from point to to almost two percent, So that is a pretty big jump, right there. Some things to note though, from this study, they were older people, so these are people fifty one to eighty
one that they were looking at. And also most of these people that were infected had milder symptoms, so they and you know, we don't know what the correlation were between the people that actually did lose their sense of smell or people that had long COVID, which attracts with some of these other neurological things like you know, the brain fog and memory loss and just kind of hard to normally function exactly. One of the big unknowns. There are many unknowns with this study. One of the big
unknowns is what was health like for these folks. Did they have symptoms, did they lose their sense of smell? Do they have long COVID? We really don't know about. The research did not have access to that kind of information, so they're sort of looking in a vacuum. What they're what they're finding is they did see brain changes, but
they cannot correlate them to people's symptoms. So yes, and they were older people, so this can not say really anything about anybody who's under fifty, and it's just sort of raising this question. I think the most definitive thing that you can say is that it is one of the strongest studies showing that something does actually change in your brain when you have COVID. We don't really know why.
There's a few def theories about what could be causing this, but it appears pretty good evidence here anyway that's having COVID can produce some kind of change in your brain. The other big unknown here is how long does this last? Because these folks were scanned only once after their COVID infection, about four and a half mon after on average, but a year out is their brain will look different. We
don't know, yah, and one of the big culprits. And they suspect that one of the big culprits is one of the big culprits that are you know, a key and a lot of the problems when people get covered inflammation, So they think inflammation plays a big part in all
of this. Yes, that's definitely one theory. Another theory that I thought was kind of interesting is that it's possible that if you're losing yourself to smell, the information, the sort of sensory information that being able to smell something carries to your brain is kind of interrupted, and so it's possible that what they call sensory deprivation is sort of causing some areas of your brain to be less active and and maybe you know, lose some of their
some of their volume. So that's kind of interesting. The one area that I think most but not everybody in the field is sort of has an sense it's about is that it doesn't appear that COVID is a virus that invade the brain directly all that often it might be able to there's some evidence that can, but that doesn't seem to be the way this virus really works. So we're probably talking about an effect that is kind
of secondary to your body's response to the infection. Well, some interesting stuff things for scientists to build off of these findings and learn a little bit more, so hopefully we can get there. Pambelic, health and science writer at the New York Times, thank you very much for joining us. Thanks so much. I'm Oscar Emiras and this has been reopening America. Don't forget that. For today's big news stories, you can check me out in the Daily Dive podcast
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