Ah, sleep. Nothing like a good dose of the stuff, right? Losing even a single wink of your usual forty (or an hour, as the case may be) is enough to throw off an entire day.

But do you know who might love sleep more than anyone or anything? Our livers.

Yes, livers. Those fleshy multivitamins with an apparent propensity for fat accumulation function best on a good night’s sleep. New research is revealing exactly why shift workers and other chronically sleep deprived members of mankind tend to have problems with obesity, insulin resistance, diabetes, heart disease, and all the other popular features of metabolic syndrome: their livers aren’t processing fat efficiently, instead allowing fat to accumulate.

Normally, teams of molecules are dispatched to the liver during the day to reduce (the totally normal) fat accumulation that occurred during the night. The teams primarily comprise two molecules, rev-erb and HDAC3, which work together to break down the liver fat. These are the day shift workers; they follow the circadian rhythm. When we don’t sleep, our circadian rhythms are disrupted. The day workers don’t show up to work at the hepatic lipid processing plant, and all the fat that accumulated during the night just sits and sits and piles up. When the workers finally return, far too much fat has built up for the teams to handle. They’re up to their neurons in it. Personally, I blame rev-erb. He’s the one with the car. He’s the one who’s supposed to drive the rest to work. HDAC3 is probably waiting on the curb, thermos and lunch pail in hand, ready to start clearing out fat, while rev-erb’s just sleeping in. Ah well – can’t really blame the workers. You have to look at the system.

Some suggest enacting a bill that removes collective bargaining rights from and reduces health benefits for hepatic lipid processing workers’ unions. I think a more prudent (and effective) approach would be to just get to bed at a reasonable time, maybe by minimizing light exposure a couple hours before sleep. For shift workers with metabolic issues who have no choice (which is, sadly, most of them) but to work those hours, the lab group is looking into whether timing the administration of drugs according to normal circadian liver metabolism would help.

All in all, this is further evidence that many (if not most) of our metabolic issues stem from liver dysfunction.

And now for something completely different. This is a totally unrelated paper but an interesting one. It presents a link between genius (IQs of 130 or greater) and prenatal exposure to higher levels of testosterone. Just as the preponderance or lack of various hormones and chemicals in utero can lead to defects or deficiencies, these researchers are proposing that the opposite can happen. Seems reasonable. But wait – before you budding parents start cycling anabolics, use a little caution. There are also links between high testosterone in the womb and autism or autism-like symptoms, and some researchers are deeming these links quite robust. I wonder if there are safe ways to fiddle with prenatal hormone exposure. Probably not.

How does a poor night’s sleep affect your metabolic health? Do you feel the acute effects right away, or do you need to get poor sleep for an extended period of time before it starts to hit you? Also, would you consider playing around with hormone levels in the womb if it meant your kid might turn out to be a genius? Let me know in the comment section!

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