Previous: Paleontology's Technicolor Moment
Next: Bears Have Babies While They’re Hibernating



View count:77,871
Last sync:2022-11-29 20:15
Go to to start streaming Ancient Engineering. Use code SciShow to sign up, just $14.99 for the whole YEAR.

Detecting diseases early can be a big help when it comes to treating them, and researchers may have gotten one step closer to diagnosing Alzheimer's with a simple blood test.

Hosted by: Stefan Chin

SciShow is on TikTok! Check us out at
Support SciShow by becoming a patron on Patreon:
Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever:

Bryan Cloer, Chris Peters, Matt Curls, Kevin Bealer, Jeffrey Mckishen, Jacob, Christopher R Boucher, Nazara, charles george, Christoph Schwanke, Ash, Silas Emrys, Eric Jensen, Adam Brainard, Piya Shedden, Alex Hackman, James Knight, GrowingViolet, Sam Lutfi, Alisa Sherbow, Jason A Saslow, Dr. Melvin Sanicas, Melida Williams, Tom Mosner

Looking for SciShow elsewhere on the internet?
SciShow Tangents Podcast:








Thanks to CuriosityStream  for supporting this episode!

Go to  to start streaming thousands of documentaries  and nonfiction TV shows. [♪ INTRO]. Detecting diseases early can be a big  help when it comes to treating them.

And in the case of age-associated cognitive  disorders like Alzheimer’s disease, by the time someone starts showing  symptoms, their disease is harder to treat. So we really want to spot it earlier. Luckily, research published this week  in EMBO Molecular Medicine suggests we may soon be able to spot it way  earlier, thanks to a simple blood test.

The study involved looking for combinations of biomarkers, which is a broad term for a  biological measurement of the body that tells you something that’s  both reproducible and accurate. That can be anything from a molecule  in your blood, to your blood pressure. In this case, the scientists were looking for combinations of molecules called microRNAs.

They’re little strands of genetic material  that influence what kind of proteins get made, and how much of them. It’s made from the same building  blocks as the mRNA that goes into some. COVID vaccines, but microRNAs serve  a very different role in the body.

Different combinations of microRNAs can  point to different pathologies in the body. And a few combinations have already  been implicated in things like memory impairment and Alzheimer’s disease. So the study set out to identify  whether certain microRNAs show up before someone develops signs of  age-associated cognitive disorders, such as Alzheimer’s.

The researchers first used a combination  of cognitive and blood tests in young humans with no signs of  cognitive disorders to identify a bunch of candidate microRNAs  associated with cognition. Then, they did a bunch of research  in mice and cell culture to narrow it down to a combination  of three specific microRNAs potentially associated with  age-related cognitive disorders. They then took those findings and  applied them to a previous data set of patients with mild cognitive impairment.

In some patients, MCI can be a warning  sign of Alzheimer’s disease, but not all. The researchers spotted their  combination of microRNAs most strongly in the blood of patients whose  MCI would convert to Alzheimer’s within two years of the blood sample being taken. And the signal was lower in other  MCI patients from that data set.

So the authors of the paper conclude  that that signature group of 3 microRNAs might predict whether MCI will convert  to Alzheimer’s within a few years. Now their blood test still  needs to be tested further, and it isn’t ready for your  doctor’s office quite yet. Plus, they weren’t able to  identify a specific disease, just that this biomarker was  associated with cognitive decline.

The researchers also still need to measure  these microRNAs over a longer period of time to really confirm that they  predict age-associated cognitive disorders. But the research team is hopeful that  someday this test could be a routine screening test in the doctors’ office, which  would let the patient go on to get formal diagnostic testing or kick off  their treatment as soon as possible. But the researchers also hope their  findings might give way to a treatment.

Their mouse models suggest blocking the  action of those molecules could improve cognitive performance, but for  now, that’s hashtag in mice. So while this blood test isn’t  close to ready for the public yet, there’s reason for hope, which we’re big fans of. And now, if you’re ready to lighten  the mood from Alzheimer’s, guess what?

Scientists discovered  something cool in poop. Again. Specifically, researchers publishing in  Current Biology this week described how humans drank beer and ate blue  cheese over two thousand years ago.

Fecal samples don’t usually last for  thousands of years, but thanks to the uniquely salty and cool environment of  the Hallstatt salt mines in Austria, the researchers were able to  obtain multiple samples of paleofeces, also known as old poop. They also found everything from wooden  tools, to furs, to old clothing. But for this study, the researchers were  interested in learning about the diets, and gut bacteria, of these ancient folks.

And that’s where the paleofeces come in. They subjected four samples to  carbon dating and found that they ranged from over a millennium BCE  all the way through the 1700s. And from those samples, they  were able to look at some of the.

DNA and proteins within. This is what  gave them clues about the ancient diets. They were able to reconstruct the  gut microbes from the paleofeces and compared them to modern microbiomes.

They also wanted to see if they could  find out what kind of food was in the sample itself. So they broke apart  the samples and looked at them under a microscope, where they found remnants  of all kinds of grains and seeds. Given their gut microbes and the microscopic  food bits, the scientists were able to infer that they probably ate mostly grains  and vegetables, but also chowed down on fruits, nuts, and meat every now and then.

The researchers also found something unexpected. One sample about 2700 years old  had large amounts of two fungi: one used to brew beer, and  one found in blue cheese. They followed up these findings with a  few other molecular tests to make sure these fungi were actually ancient, and  not contaminants from over the years.

Sure enough, both the beer and blue  cheese fungi were indeed ancient. They were able to reconstruct  each fungi’s genome and found they showed signs of older DNA. Now, we’ve known that our  ancestors have been fermenting beer and wine for millennia, but that evidence mostly comes from  ancient writing and analysis of old plants.

This study was the first time  we’ve been able to tell that from a sample that used to be inside a human body. And for you cheese lovers, this is  actually the earliest evidence for humans in Europe eating aged and ripened cheese. In the future, researchers want to  continue analyzing more samples, to get a more complete picture  of the diet of ancient humans.

And if you want to know what else  were humans up to in the olden days, you might like today’s sponsor CuriosityStream. They’re a subscription streaming  service that offers thousands of documentaries and non­fiction TV shows  from some of the world's best filmmakers. Their original series “Ancient  Engineering” will show you how ancient cultures built all sorts of amazing things,  from the Great Pyramid to Angkor Wat.

And you can sign up for a whole year of  CuriosityStream for under fifteen bucks, so if you’re interested, you can get  started at [ OUTRO ].