There's an additional category that I want to highlight, of course, and this is vitally important to state, even though it's obvious, which is that people who are pregnant should absolutely not consume alcohol. Fetal alcohol syndrome is well-known and established. It's terrible. Fetuses experience diminished brain development that's often permanent, diminished limb development, diminished organ development in the periphery, meaning the heart, the lungs, the liver, et cetera.

Ingesting alcohol while pregnant is simply a bad idea. And the reason I say this at all is, first of all, it's important to include in an episode like this, but also because we can look at two things. First of all, we can look at mechanism, and then we can also look at some of the lore that still sadly exists out there.

Let's take care of the lore that sadly exists first. If you look online, you will sometimes be able to find, sadly, that some people believe that certain kinds of alcohol are not detrimental to fetuses. They'll say, well, champagne is safe for a pregnant mother to drink, but beer is not.

That is absolutely categorically false. Alcohol is alcohol. There is no evidence whatsoever that consuming certain types of alcohol is safer for fetuses than others. Alcohol is a toxin, and the reason fetal alcohol syndrome exists is because the ability of that toxin to disrupt cellular processes. Remember tumor growth and the way that alcohol can accelerate tumor growth by proliferation of cells, the wrong cells, the ones you don't want to proliferate?

Well, all of embryonic development, all of fetal development, it's not the growth of a tumor. It's obviously the growth of an embryo, and it's done in a very orchestrated way. I started off studying brain development. That's where I got my beginnings in neurobiology, and I still teach embryology to medical students and graduate students.

The set of coordinated processes that has to take place from conception to birth in order to give rise to a healthy embryo is so, so dynamically controlled and so exquisitely precise with checkpoints and recovery mechanisms and redundancy in the genes that are expressed to make sure that if anything goes wrong, it's repaired, et cetera.

Alcohol as a mutagen, I haven't used that word yet, but a substance that can mutate DNA through alterations in DNA methylation and these checkpoints in the cell cycle. Alcohol as a mutagen is one of the worst things that a developing embryo can be exposed to. And again, because it's water-soluble and fat-soluble, ingestion of alcohol when people are pregnant passes right to the fetus.

Now, I realize that a number of people out there might be thinking, "Oh, goodness, you know, "I didn't realize I was pregnant "until a certain stage of pregnancy, "and before I realized I was ingesting alcohol." Obviously, one can't undo what's been done, but I want to also emphasize that fetal alcohol syndrome, while yes, there's a full-blown syndrome that manifests as changes in the craniofacial development that are very obvious, and you can look these up.

You've probably seen these before, or the pictures before, rather. It has to do with eye spacing, forehead size, a number of other features of the craniofacial development, and of course, stuff's going on in the brain too. It's along a continuum. So it is possible that some of the changes that occur are more minor, and thankfully, the young brain, in particular the early postnatal brain, is incredibly plastic.

There are things that can be done in order to help recover neural circuits that didn't develop well, et cetera. But even though it's somewhat obvious, or should be obvious, I really want to make clear that there's zero evidence whatsoever that certain forms of alcohol are safer for pregnant women to ingest than others.

Absolutely wrong. No one who's pregnant should be ingesting alcohol whatsoever. And certainly, if people feel like they can't avoid alcohol while pregnant, they really need to work with somebody to make sure that it just absolutely doesn't happen because it is so detrimental to the developing fetus. (upbeat music)