Two sleep studies recently showed up in the nuance-free spin machine known as digital media, and the headlines they spawned are doing what wellness headlines often do: turning provocative evidence into a unanimous — if false — verdict.

The first study, of about half a million British adults, found that people sleeping between 6.4 and 7.8 hours a night had the youngest-looking organs. Sleep less, or more, and you're in the "aging faster" cohort, which also had higher rates of 153 diseases and died sooner than those who stayed within the 6.4 to 7.8-hour range.

The second study found that long-term melatonin users had an 89% higher rate of new heart failure than non-users. The study compared 65,000 melatonin users with 65,000 non-users, all of them insomniacs, and followed them for five years. The melatonin group was hospitalized for heart failure about three and a half times as often and died at twice the rate.

The findings were presented in November at the American Heart Association's annual meeting.

What Neither Study Can Actually Prove

Here's what neither study can do, and what no headline I've seen admits: prove that sleep, or the supplement, caused any of it.

Both studies are observational, meaning they only watched people. That kind of research can tell you what tends to travel together. It can't tell you which one is driving the other.

For instance, in the sleep study, the likeliest reason that longer sleepers had higher mortality rates is that lengthier sleeps are often a symptom of something already wrong, not a cause of decline. A guy sleeping 10 hours may be dealing with a chronic illness, inflammation, injury or another health struggle.

The sleep-study chart can't separate the two, and its authors, to their credit, say so.

Now let's examine the melatonin study. Everyone in it already had insomnia bad enough to take a nightly sleep aid for a year or more, and insomnia itself is hard on the heart. So which way does the arrow point? Did the melatonin sicken these people, or did already-sick people reach for melatonin? The study can't say, and, thankfully, its lead author acknowledged that. He also said the takeaway isn't that melatonin was bad and that people shouldn't take it.

A couple of other things keep that melatonin association with (not necessarily cause of) heart failure in proportion. One is that other research this year suggests melatonin actually helps heart-failure patients. Though that was presented as a conference abstract, which is the rawest form that new research takes, and was not yet peer reviewed, online media worldwide tended to run it as an established fact.

How Thin Evidence Becomes a Sales Pitch

This is the pattern I've been writing about for a while now. A study finds a correlation. A press release sands off the caveats. A headline turns "associated with" into cause and effect. And a supplement company, or a sleep-tracker brand, folds the result into a sales pitch.

What You Can Take to the Bank

What's actually useful from these two studies is smaller than either headline. The sweet spot for sleep duration looks real, and it's modest: closer to seven hours for most people than the eight of folklore, and nowhere near the heroic 10 that some people brag about. (Although some people surely need 10 hours a night.)

That's worth knowing. It's also free. The melatonin question is harder.

The safety data on long-term use is thinner than the supplement's profit margins, certainly. Melatonin isn't even approved in the United States to treat insomnia. A 2023 JAMA analysis tested 25 melatonin gummy products and found 22 were mislabeled — some carrying nearly triple the dose printed on the box.

If you've been swallowing one nightly for years, you may want to inform your primary health provider. Especially if your heart already gives you reason to pay attention.

The one thing to remember from this column is to not take headlines about longevity research and supplements at face value and, instead, read the studies directly.

Or ask your favorite AI to read it and give you its opinion on the headline. Vetting medical and longevity-industry research, in fact, is one way to use AI to help, instead of complicate, your life.

To find out more about Paul Von Zielbauer and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

Photo credit: Julia at Unsplash