Ivanka Trump's New Year's Resolution: Get More Sleep. What Does the Science Say?

On December 27, Ivanka Trump tweeted "New Year resolution, sleep more" to her 5.12 million followers, along with a link to a USA Today article about how "sleep deprivation is toxic and will eventually kill you."

One could choose to interpret this as a subtweet aimed at her father, who reportedly sleeps very little, though it's much more likely this simply struck her as a helpful, non-controversial wellness tip, which it is. But let's not forget that there was pushback when Michelle Obama advised Americans to drink more water (that story ran in USA Today, too), a similarly safe-sounding piece of advice that wasn't entirely backed by science. So, is sleep deprivation "toxic" after all?

The science the article refers to is sound, if not new.

You may have heard the refrain that a human being can survive for about three minutes without oxygen, three days without water and three weeks without food. But as noted by the article's author, entrepreneur and brain scientist Jeff Stibel, sleep is as vital a commodity as any of those things, and without it we'll die in roughly 11 days.

After around 200 hours, the accumulation of toxins in our brains reach deadly levels, Stibel wrote. (Two hundred hours is a little more than eight days—the source of the discrepancy is unclear, but might be accounted for by the fact that getting limited sleep can keep us going a little longer).

In 2013, Danish researchers found that in mice, the brain performs a nightly, highly efficient "self-clean" of the toxic waste produced by the body's cells—essentially taking out the day's trash, the Washington Post reported.

Without that opportunity, toxins accumulate, including the beta-amyloid protein, which has long been linked to Alzheimer's disease. While the mice slept, their brains compressed, flushing out the water weight of the blood that swells them when the heart is pumping more vigorously during the day, when they're active. In this manner, harmful toxin build-ups get flushed out, too.

In 2014, The New York Times ran a similar piece on the research, explaining that the lymphatic system that cleans waste out from our bodies can't reach the cellular waste in our brains.

"Think about a fish tank," corresponding author Maiken Nedergaard, a Danish biologist leading sleep function research at the University of Rochester's medical school, told the Times. "If you have a tank and no filter, the fish will eventually die. So, how do the brain cells get rid of their waste? Where is their filter?"

Nedergaard explained to the Times that her research showed the brain has its own equivalent, which she called the glymphatic system (so named for its reliance on glial cells—protective cells within the brain—and the analogous lymphatic system).

As Stibel wrote in USA Today, when the brain shrinks during sleep, cerebrospinal fluid (the liquid cushion that keeps your brain from getting knocked around inside your skull) flows into the brain to replace the blood that flows out. Every 90 minutes, as we cycle through the brain's natural sleep stages, the fluid flows in and out, like a tide.

"This is evolution at its finest," wrote Stibel. "The brain takes aim at two birds, using the cerebral fluid both for protection and for cleaning."

Sleep is one of those areas of research, like nutrition or mental health, that's notorious for being contradictory and fickle. Getting "more" sleep, or drinking "more" water, could mean anything. Michelle Obama, of course, worked a lot harder on her "Drink Up" campaign than Trump did on this tweet, but the issue was that there isn't really any hard science that says we should drink a certain volume of water per day. In 2015, the National Sleep Foundation published new guidelines in an attempt to clarify exactly what "normal" sleep should refer to: seven to eight hours per night for older adults.