efore he died last year, William M Pardridge was the most illustrious
scientist in the field of blood-brain barrier research.
His reputation took a bit of a beating when his paper claiming the heretofore unimaginable feat of getting a fraction of a microgram of DNA into a brain turned out to be an artifact. No one blamed Pardridge. It's easy to make an elementary mistake while you're looking for things in the brain. Good scientists and bad ones have all done it.
I worked on this field, the blood-brain barrier—mostly under duress—for about a year. It is by far the most miserable branch of neuroscience. You will never meet a more wretched hive of scientists in the depths of despair than at a BBB conference. Anyone who thinks you can get five grams of anything that doesn't belong there into a human brain has no clue how hard the problem is.
Now, in a new paper, scientists claim to have gotten a million times more into a human brain. Not of something easy like sucrose or DNA, but plastics. The press are saying they found one teaspoon which the Internet informs me is equivalent to 4.93 grams. For a typical brain weighing 1300 grams, this would mean the brain is 0.38 percent plastic. Yet everyone is becoming hysterical, saying microplastics cause inflammation and are “linked” to Alzheimer's disease and even cancer.
Much of my career I worked with postmortem human brain slices and tissues. I found “microplastics” in all of them. It even seemed there were more in Alzheimer brains than controls. And there were lots of microplastic particles and fibers in cultured cells, all in higher levels in cells treated with beta-amyloid, a marker for Alzheimer's.
So I investigated them. After days of doing rigorous controls of the reagents, the culture dishes, the cells, the brain extracts, and the medium, I found that all of them contained microplastics when I filtered the solution through a syringe filter. None of them contained microplastics until these filtered solutions were added to them. The particles were being released from the syringe filters we used to sterilize our solutions.
Imagine if Biogen, the only big pharma company that is still trying to find treatments for brain diseases, could get five grams of a drug into the brain. We'd have cures for brain cancer, Parkinson's, and Alzheimer's in a month.
I'll post a more technical article in a day or so. But this claim is almost certainly not going to hold up.
As for Dr Pardridge, he's probably spinning in his grave about now. Bill, this unfiltered beer is for you.
feb 06 2025
