Issue 73

Useless toothpaste, the most common concussions, and in-demand organs

June 1, 2019

Hello friend! Welcome to Scrap Facts.

I'm a reporter covering health and science with insatiable curiosity. I love everything I learn, not all of which gets its own story. Each week, I'll bring you some of my favorite facts that I picked up on the job or while out living life.

Archives from Tinyletter can be found here.


The Superhuman Condition—a format remix.

A breakdown of an obsession I lead at Quartz.

At Quartz, reporters don’t necessarily have beats. Instead, we have lenses through which we try to view the world and look for stories. We call them obsessions.

I took a lead role in developing the Superhuman Condition obsession with input from others focused on science and health news at Quartz. In short, it focuses on the long-term consequences of scientific and medical breakthroughs.

Falling costs of better technologies mean that more of us have access to treatments and preventative care that have greatly extended global life expectancy. This kind of progress is great for humanity, but comes with new challenges.

Individually, a longer life means a person will be at increased risks for age-related diseases, like heart disease and cancers. I’m particularly fascinated by neurodegenerative diseases, which usually strike later in life as our brains start to deteriorate faster than normal aging.

As more people across the globe live longer, a larger portion of people will be older, and therefore more susceptible to more of these age-related conditions. There will be more of us needing more resources like food and housing, and more medical care than ever before. There’s also the issue of inequality: Right now, only the rich have access to some of the best technology that keeps us alive and healthy for longer.

And finally, no matter how good science gets for all of us, we’re still all going to die. Death is a reality that should compel us to take advantage of our time here. The way we spend our final days, and how we choose to die, will also change as we continue to live longer.

I’m going to start writing more about how I’m thinking about the Superhuman Condition with a brief essay here each newsletter.

The scrap facts will continue, of course. My goal is always to bring you the wonder behind medical developments or stories about science. I also hope I can shed a light about the ways that we’re thinking about the downstream consequences of them, too.

Scrap Facts premium.

This month, I’ll be launching a paid version of this newsletter. For just $3/month, you’ll get four emails per month. Two will be this newsletter, but the other two will include interviews with other scientists and/or communicators and/or field experts where I talk to them about their scrap facts. I’ll keep you posted when and how to sign up!


Charcoal toothpaste may make it harder for your teeth to absorb a mineral critical for dental health.

Found while reporting: Charcoal toothpaste is worse for your teeth, not better.

Charcoal toothpastes are all the rage. It seems like their popularity stems from charcoal’s abrasiveness, which can help whiten teeth, and its absorptive properties.

While it’s true that charcoal can be used medicinally to absorb certain poisons in the stomach before they reach the bloodstream, charcoal in toothpaste may actually take up fluoride intended for your teeth. Fluoride, when combined with calcium and phosphate from your teeth, helps build up enamel, which delays tooth decay. It’s an added chemical to most public water and toothpastes.

If fluoride can’t reach your teeth, though, it’s essentially useless.

On top of that, most charcoal toothpastes don’t even contain fluoride—they buy into a conspiracy theory that started in the 50s that believes the fluoride in public water is poisonous. It isn’t. Fluoride can be dangerous, but at levels much higher than that in water supplies and toothpastes.

And on top of that, charcoal can sometimes be too abrasive for our teeth. The whitening properties can wear down teeth too quickly. So really, not a great bandwagon to jump on.

The demographic that gets concussions the most are not professional athletes.

Found while reporting: Concussions later in life double dementia risks, but statins may help.

Most concussions occur in surprisingly mundane situation. They can happen hitting your head against something, falling, or car crashes. (I myself have had one concussion, which I obtained camping. I accidentally walked into a wooden beam in a lean-to on the Appalachian trail.)

All these scenarios are more common among older adults. As such, adults over 75 happen to have the highest rates of all traumatic brain injuries, per the US Centers for Disease Control.

Fortunately, these rates are pretty low; about 2.2% and 1.5%, respectively. Unfortunately, any concussion effectively doubles a person risk for developing some form of dementia later in life. There are no hard and fast statistics, but the background rate of dementia is around 19 or 20 cases per 1,000 people. Still, it’s worth telling your doctor if you’ve ever had a concussion if you have other risks for developing dementia, like high blood pressure.

The most in-demand organs for transplants are ones we already have machines to replicate.

Found while reporting: These are the organs transplant patients need the most.

Image description: A chart of the waitlist for organs needed in the US. Full chart available here.

The supply of donated kidneys greatly misses the massive demand for those who are in renal failure. This surprised me, because dialysis—a process that externally replicates the filtering function of the kidneys—has existed since the 1940s. There’s no artificial function for the next most-needed organ, which is the liver.

Dialysis, though, is hard on the body; most patients who get kidney transplants do better than those who keep getting rounds of dialysis. And the total burden of kidney disease, which can be caused by a number of conditions including diabetes, is much, larger than the burden of liver disease or heart disease that’s bad enough to require a transplant.

Stuff I learned from others:

The 2008 financial crisis led to the rise of #influencers. Some millipede genitals glow in UV light, but probably not for any practical reason. Cyclist-friendly streets are safer for cars, too. Forget natural gas, it’s “freedom gas.” Measles erases the immune system’s memory of other infections.

Animal of the week: English bulldogs.

Bulldogs got their name from being bred in the UK to fight bulls, before it was banned in 1835. Their chonky bodies made them pretty hard to move if a bull hit them, and their loose skin protected their internal organs. Today, they make make good mascots. Hoya Saxa as I head to my five-year reunion this weekend.

Image description: an instagram of Jack the Bulldog sitting near the front gates of Georgetown University.

That’s all for now. Stay curious, friend! <3

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Image description: a sketched headshot of me.

Top image by E. Y. Smith, headshot drawing by Richard Howard.