A thick sphere of icy debris known as the Oort cloud shrouds the solar system. Other star systems may harbor similar icy reservoirs, and those clouds may be visible in the universe’s oldest light, researchers report.
Astronomer Eric Baxter of the University of Pennsylvania and colleagues looked for evidence of such exo-Oort clouds in maps of the cosmic microwave background, the cool cosmic glow of the first light released after the Big Bang, roughly 13.8 billion years ago. No exo-Oort clouds have been spotted yet, but the technique looks promising, the team reports November 2 in the Astronomical Journal. Finding exo-Oort clouds could help shed light on how other solar systems — and perhaps even our own — formed and evolved. The Oort cloud is thought to be a planetary graveyard stretching between about 1,000 and 100,000 times as far from the sun as Earth. Scientist think that this reservoir of trillions of icy objects formed early in the solar system’s history, when violent movements of the giant planets as they took shape tossed smaller objects outward. Every so often, one of those frozen planetary fossils dives back in toward the sun and is visible as a comet (SN: 11/16/13, p. 14).
But it’s difficult to observe the Oort cloud directly from within it. Despite a lot of circumstantial evidence for the Oort cloud’s existence, no one has ever seen it.
Ironically, exo-Oort clouds might be easier to spot, Baxter and colleagues thought. The objects in an exo-Oort cloud wouldn’t reflect enough starlight to be seen directly, but they would absorb starlight and radiate it back out into space as heat. For the sun’s Oort cloud, that heat signal would be smeared evenly across the entire sky from Earth’s perspective. But an exo-Oort cloud’s warmth would be limited to a tiny region around its star.
Baxter and colleagues calculated that the expected temperature of an exo-Oort cloud should be about –265° Celsius, or 10 kelvins. That’s right in range for experiments that detect the cosmic microwave background, or CMB, which is about 3 kelvins. The team used data from the CMB-mapping Planck satellite to search for areas across the sky with the right temperature (SN Online: 7/24/18). Then, the researchers compared the results with the Gaia space telescope’s ultraprecise stellar map to see if those regions surrounded stars (SN: 5/26/18, p. 5).
Although the astronomers found some intriguing signals around several bright, nearby stars, it wasn’t enough to declare victory. “That’s pretty interesting, but we can’t definitively say that it’s from an Oort cloud or not,” Baxter says.
Other ongoing CMB experiments with higher resolution, like those with the South Pole Telescope and the Atacama Cosmology Telescope in the Chilean Andes, could confirm if those hints of exo-Oort clouds are real.
“It’s a super clever observational idea,” says astronomer Nicolas Cowan of McGill University in Montreal who was not involved in the new work. “Looking for exo-Oort clouds is looking for a signature of these violent histories in other solar systems.”
Cowan has suggested that the cosmic microwave background could also be used to search for a hypothetical Planet Nine in the sun’s Oort cloud (SN: 7/23/16, p. 7). “The very coolest thing would be if we could get measurements of the exo-Oort clouds and find planets in those systems,” he says.
DNA from a 9,000-year-old baby tooth from Alaska, the oldest natural mummy in North America and remains of ancient Brazilians is helping researchers trace the steps of ancient people as they settled the Americas. Two new studies give a more detailed and complicated picture of the peopling of the Americas than ever before presented.
People from North America moved into South America in at least three migration waves, researchers report online November 8 in Cell. The first migrants, who reached South America by at least 11,000 years ago, were genetically related to a 12,600-year-old toddler from Montana known as Anzick-1 (SN: 3/22/14, p. 6). The child’s skeleton was found with artifacts from the Clovis people, who researchers used to think were the first people in the Americas, although that idea has fallen out of favor. Scientists also previously thought these were the only ancient migrants to South America. But DNA analysis of samples from 49 ancient people suggests a second wave of settlers replaced the Clovis group in South America about 9,000 years ago. And a third group related to ancient people from California’s Channel Islands spread over the Central Andes about 4,200 years ago, geneticist Nathan Nakatsuka of Harvard University and colleagues found. People who settled the Americas were also much more genetically diverse than previously thought. At least one group of ancient Brazilians shared DNA with modern indigenous Australians, a different group of researchers reports online November 8 in Science. Early Americans moved into prehistoric South America in at least three migratory waves, a study proposes. Ancestral people who crossed from Siberia into Alaska first gave rise to groups that settled North America (gray arrows). The first wave of North Americans (blue) were related to Clovis people, represented by a 12,600-year-old toddler from Montana called Anzick-1. They moved into South America at least 11,000 years ago, followed by a second wave (green) whose descendants contributed most of the indigenous ancestry among South Americans today. A third migration wave (yellow) from a group that lived near California’s Channel Island moved into the Central Andes about 4,200 years ago. Dotted areas indicate that people there today still have that genetic ancestry. Genetically related, but distinct groups of people came into the Americas and spread quickly and unevenly across the continents, says Eske Willerslev, a geneticist at the Natural History Museum of Denmark in Copenhagen and a coauthor of the Science study. “People were spreading like a fire across the landscape and very quickly adapted to the different environments they were encountering.”
Both studies offer details that help fill out an oversimplified narrative of the prehistoric Americas, says Jennifer Raff, an anthropological geneticist at the University of Kansas in Lawrence who was not involved in the work. “We’re learning some interesting, surprising things,” she says.
For instance, Willerslev’s group did detailed DNA analysis of 15 ancient Americans different from those analyzed by Nakatsuka and colleagues. A tooth from Trail Creek in Alaska was from a baby related to a group called the ancient Beringians, who occupied the temporary land mass between Alaska and Siberia called Beringia. Sometimes called the Bering land bridge, the land mass was above water before the glaciers receded at the end of the last ice age. The ancient Beringians stayed on the land bridge and were genetically distinct from the people who later gave rise to Native Americans, Willerslev and colleagues found.
The link between Australia and ancient Amazonians also hints that several genetically distinct groups may have come across Beringia into the Americas.
The Australian signature was first found in modern-day indigenous South Americans by Pontus Skoglund and colleagues (SN: 8/22/15, p. 6). No one was sure why indigenous Australians and South Americans shared DNA since the groups didn’t have any recent contact. One possibility, says Skoglund, a geneticist at the Francis Crick Institute in London and a coauthor of the Cell paper, was that the signature was very old and inherited from long-lost ancestors of both groups.
So Skoglund, Nakatsuka and colleagues tested DNA from a group of ancient Brazilians, but didn’t find the signature. Willerslev’s group, however, examined DNA from 10,400-year-old remains from Lagoa Santa, Brazil, and found the signature, supporting the idea that modern people could have inherited it from much older groups. And Skoglund is thrilled. “It’s amazing to see it confirmed,” he says.
How that genetic signature got to Brazil in the first place is still a mystery, though. Researchers don’t think early Australians paddled across the Pacific Ocean to South America. “None of us really think there was some sort of Pacific migration going on here,” Skoglund says.
That leaves an overland route through Beringia. There’s only one problem: Researchers didn’t find the Australian signature in any of the ancient remains tested from North or Central America. And no modern-day indigenous North or Central Americans tested have the signature either.
Still, Raff thinks it likely that an ancestral group of people from Asia split off into two groups, with one heading to Australia and the other crossing the land bridge into the Americas. The group that entered the Americas didn’t leave living descendants in the north. Or, because not many ancient remains have been studied, it’s possible that scientists have just missed finding evidence of this particular migration.
If Raff is right, that could mean that multiple groups of genetically distinct people made the Berigian crossing, or that one group crossed but was far more genetically diverse than researchers have realized.
The studies may also finally help lay to rest a persistent idea that some ancient remains in the Americas are not related to Native Americans today.
The Lagoa Santans from Brazil and a 10,700-year-old mummy from a place called Spirit Cave in Nevada had been grouped as “Paleoamericans” because they both had narrow skulls with low faces and protruding jaw lines, different from other Native American skull shapes. Some researchers have suggested that Paleoamericans — including the so-called Kennewick Man, whose 8,500-year-old remains were found in the state of Washington (SN: 12/26/15, p. 30) — weren’t Native Americans, but a separate group that didn’t have modern descendants.
But previous studies of Paleoamericans and Willerslev’s analysis of the Spirit Cave mummy’s DNA provide evidence that, despite their skull shapes, the Paleoamericans were not different from other Native Americans of their time. And the ancient people are more closely related to present-day Native Americans than any other group.
Willerslev presented the results about the Spirit Cave mummy to the Fallon Paiute-Shoshone tribe when the data became available. Based on the genetic results, the tribe was able to claim the mummy as an ancestor and rebury the remains.
Disinfection of public drinking water is one of the great public health success stories of the 20th century. In 1900, outbreaks of cholera and typhoid, both caused by waterborne bacteria, were common in American cities. In 1908, Jersey City, N.J., became the first U.S. city to routinely disinfect community water. Other cities and towns quickly followed, and by 1920, the typhoid rate in the United States had dropped by 66 percent.
But that battle isn’t over. Around the world, more than 2 billion people lack reliable access to safe water (SN: 8/18/18, p. 14), and half a million people die each year from diarrhea caused by contaminated water, according to the World Health Organization. And in the United States, challenges remain. The management failures that caused the 2014 lead contamination crisis in Flint, Mich., were a wake-up call (SN: 3/19/16, p. 8), but Flint is hardly alone. Systems in other big cities are also falling short. In October, officials in Newark, N.J., scrambled to hand out home water filters after it became clear that efforts to prevent lead from leaching into drinking water were not getting the job done. In the first six months of 2017, more than 22 percent of water samples in that city exceeded federal limits for lead, according to news reports.
If big cities are struggling, small towns with skimpy budgets as well as the many people who get their water from private wells often have it harder, lacking access to the infrastructure or technology to make water reliably safe. But science can help.
In this issue, Science News staff writer Laurel Hamers digs into the latest research on water treatment technology and finds a focus on efforts to invent affordable, scalable solutions. There’s a lot of engineering and chemistry involved, not surprisingly, and also physics — it’s hard to move water efficiently through a filter while also catching the bad stuff. Her story is a testament to researcher ingenuity, and a helpful primer on how a typical municipal water treatment plant works.
As I read Hamers’ story, I realized that I didn’t know how our water is treated here in Washington, D.C., even though I live barely a mile from one of the city’s two treatment plants. (I at least get credit for knowing the water comes from the Potomac River.) So I Googled it and found a description of how that process works. Plus I found data on potential contaminants such as Giardia and Cryptosporidium, as well as information on how residents can get their water tested for lead, which can leach from pipes or fixtures. I also learned that each spring, the Washington Aqueduct briefly switches disinfectants from chloramine to chlorine while the agency cleans the water pipes. That might explain the short-lived swimming pool smell in the tap water.
For me, this became a double win; I learned a lot about advances in water treatment technology from Hamers’ reporting, and I was motivated to seek out information about my local water supply.
If other readers feel inspired by our work to learn more, count me as a happy journalist.
A newly designed airplane prototype does away with noisy propellers and turbines.
Instead, it’s powered by ionic wind: charged molecules, or ions, flowing in one direction and pushing the plane in the other. That setup makes the aircraft nearly silent. Such stealth planes could be useful for monitoring environmental conditions or capturing aerial imagery without disturbing natural habitats below.
The aircraft is the first of its kind to be propelled in this way, researchers report in the Nov. 22 Nature. In 10 indoor test flights the small plane, which weighs about as much as a Chihuahua, traveled 40 to 45 meters for almost 10 seconds at a steady height, even gaining about half a meter of altitude over the course of a flight. Most planes rely on spinning parts to move forward. In some, an engine turns a propeller that pushes the plane forward. Or a turbine sucks in air with a spinning fan, and then shoots out jets of gas that propel the plane forward.
Ionic wind is instead generated by a high-voltage electric field around a positively charged wire, called an emitter. The electricity, often supplied by batteries, makes electrons in the air collide with atoms and molecules, which then release other electrons. That creates a swarm of positively charged air molecules around the emitter, which are drawn to a negatively charged wire. The movement of molecules between the two wires, the ionic wind, can push a plane forward. The current design uses four sets of these wires. Moving ions have helped other things to fly through the air, such as tiny airborne robots. But conventional wisdom said that using the approach to move something through the air as big as an airplane wasn’t possible, because adding enough battery power to propel a plane this way would make it too heavy to stay aloft. (The ion thrusters that propel spacecraft through the vacuum of space work in a very different way and aren’t functional in air.) Attempts to build ion-propelled aircraft in the 1960s weren’t very successful. MIT aeronautics researcher Steven Barrett thought differently. With the right aircraft design and light enough batteries, flight might be possible, his initial calculations suggested. So he and his team used mathematical equations to optimize various features of the airplane — its shape, materials, power supply — and to predict how each version would fly. Then the researchers built prototypes of promising designs and tested the planes at the MIT indoor track, launching them via a bungee system. “The models and the reality of construction don’t always match up perfectly,” Barrett says, so finding the right design took a lot of tries. But in the new study, he and his collaborators report success: 10 flights of the aircraft, which has a 5-meter wingspan and weighs just under 2.5 kilograms.
Barrett’s team isn’t the only one who thought the ionic wind method might take off. Based on calculations done in his lab, “we were confident that this could be done,” says Franck Plouraboue of the Toulouse Fluid Mechanics Institute in France, who wasn’t part of the research. “Here they’ve done it — which is fantastic!”
It’s an example of distributed electric propulsion, says Plouraboue — spreading out the thrust-generating parts of the plane, instead of having one centralized source. That’s a hot area for aircraft research right now. NASA’s X-57 Maxwell plane, for example, bears 14 battery-operated motors along its wings. Increasing the number of propellers makes the plane go farther on the same amount of energy, says Plouraboue, but also increases the drag. With ionic wind propulsion, increasing the number of wires doesn’t increase drag very much.
The plane still needs some upgrades before it’s ready for the real world: Its longest flight was only 12 seconds. And while the aircraft can maintain steady flight for a short time once launched, it can’t actually get off the ground using ionic wind.
Even with improvements, ion-propelled aircraft won’t find their niche as passenger planes, predicts Daniel Drew, an aerodynamics researcher at the University of California, Berkeley, who was not involved in the work. (Drew has designed miniature flying bots that fly using ionic propulsion.) It’s probably not feasible to scale up to something the size of a 747 — there are efficiency trade-offs as planes get bigger, he says. But down the road, the approach might be useful for small, uncrewed planes or drones.
From tales about whales to enthralling scientific histories and the memoir of a frustrated astrophysicist, 2018 was a banner year for science books. Here are Science News’ picks for the titles that should be on any science lover’s bookshelf. Find detailed reviews of many of these books in the links below and in our Editor’s Pick: Favorite books of 2018.
The Truth About Animals Lucy Cooke
A zoologist debunks myths about bats, pandas, Adélie penguins and many other misunderstood creatures, recounting surprising stories from the animal kingdom (SN: 4/14/18, p. 26). Basic Books, $28
Spying On Whales Nick Pyenson
In this captivating look at whales, a paleontologist dives into the animals’ past, exploring how some of Earth’s most intelligent species came to be, and their uncertain future (SN: 7/7/18, p. 29). Viking, $27
Eager Ben Goldfarb
Some people see beavers as pests. But a science writer explains how the dam-building rodents are actually vital ecosystem engineers that can create or expand habitats that benefit the entire wildlife community (SN: 8/4/18, p. 28). Chelsea Green Publishing, $24.95
The Rise and Fall of the Dinosaurs Steve Brusatte
In this memoir, a paleontologist blends experiences from his career with evolutionary science to take readers on an engrossing journey through time, from the beginnings of the dinosaurs to their ultimate extinction. William Morrow, $29.99
The Big Ones Lucy Jones
A seismologist examines past catastrophic natural disasters, including volcanic eruptions, earthquakes and floods, and their impact on culture, politics and society (SN: 3/31/18, p. 26). With the past as a guide, the author warns readers to be prepared for when the next disaster strikes. Doubleday, $26.95
Losing the Nobel Prize Brian Keating
An astrophysicist’s dream of winning a Nobel Prize turned to dust after a promising experiment failed to find the first definitive evidence of cosmic inflation. The experience revealed how the prize can hamper scientific progress (SN: 4/14/18, p. 27). W.W. Norton & Co., $27.95
The Poisoned City Anna Clark
Weaving together history, science and reporting, a journalist explores the public health crisis that began in Flint, Mich., when lead started leaching into residents’ drinking water (SN: 7/21/18, p. 28). Metropolitan Books, $30
The Poison Squad Deborah Blum
A Pulitzer Prize–winning journalist tells the story of a government chemist at the turn of the 20th century and his mission to make food safe in the United States. Penguin Press, $28
Aroused Randi Hutter Epstein
The history of endocrinology makes for a strange and fascinating read, from the scientists who discovered the effects of hormones to the people whose lives have been irrevocably changed by these powerful substances (SN: 7/7/18, p. 28). W.W. Norton & Co., $26.95
Nine Pints Rose George
Blood, the feared as well as revered substance that flows throughout the human body, has a rich historical and scientific past (SN: 10/27/18, p. 28). Metropolitan Books, $30
She Has Her Mother’s Laugh Carl Zimmer
This comprehensive history recounts how researchers have come to understand genetic inheritance. Looking to the future, the author considers risks of gene manipulation (SN: 6/9/18, p. 29). Dutton, $30
Genetics in the Madhouse Theodore M. Porter
Using archival records, a science historian traces the origins of the study of human heredity to insane asylums in the 1800s (SN: 7/7/18, p. 29). Princeton Univ., $35
The Tangled Tree David Quammen
In chronicling the lives of researchers who made important advances in molecular biology and genetics, this book shows how recent findings shake up our understanding of evolution and the tree of life. Simon & Schuster, $30
An orbital oopsie has led to new proof of Albert Einstein’s physics prowess.
In 2014, two satellites intended for Europe’s Galileo network, the equivalent of the United States’ GPS network, were placed into orbit incorrectly, causing them to travel around Earth in ellipses rather than circles. That wasn’t ideal for the satellites’ originally intended navigational use, but scientists realized the wayward satellites were perfect for another purpose: testing Einstein’s theory of gravity, the general theory of relativity.
According to general relativity, gravity affects not just space, but also time. The deeper within a gravitational field you are, the slower time passes (SN: 10/17/15, p. 16). So a clock at a higher altitude will tick faster than one closer to Earth’s surface, where Earth’s gravity is stronger. The satellites’ orbital mishap allowed the most precise test yet of this effect, known as gravitational redshift, two teams of scientists report in a pair of papers in the Dec. 7 Physical Review Letters.
As the two misplaced satellites move in their elliptical orbits, their distance from Earth periodically increases and decreases by about 8,500 kilometers. Using the precise atomic clocks on the satellites, the scientists studied how that altitude change affected the flow of time. The clocks sped up and slowed down by tiny fractions of a second as expected, agreeing with the predictions of general relativity within a few thousandths of a percent, the teams report.
Poop contains a lot of valuable scientific information. Researchers can monitor microbes, track enzyme activity or hunt for DNA to gather clues about overall health.
There’s so much one can learn from the waste product that microbiologist Aadra Bhatt at the University of North Carolina at Chapel Hill decided there should be a word for that research — something in the same vein as “in vivo” (research done in living animals) and “in vitro” (research done in a petri dish).
After some linguistic digging, she and two colleagues settled on “in fimo.” The term comes from fimus, one of several Latin words for manure or excrement. Their choice won out over the more obvious option of “in feces” because the word feces doesn’t have the same rich scatological legacy — originally it referred to the dregs in a wine cask, Bhatt says.
She and her colleagues, while already using in fimo at meetings and seminars, published their argument online December 13 in Gastroenterology. Compared with the laborious process of pulling together a scientific paper, coming up with this term was “delightful — and it wasn’t particularly drawn out,” Bhatt says. She hopes the word catches on and gains a place in the lexicon for poopetuity.
SEATTLE — Astronomers have spotted a second repeating fast radio burst, and it looks a lot like the first. The existence of a second repeating burst suggests there could be many more of the mysterious signals in the cosmos.
The burst, called FRB 180814.J0422+73, is one of 13 newly discovered fast radio bursts, or FRBs — brief, bright signals of radio energy that come from distant galaxies. The FRBs were detected over a few weeks last year by the Canadian Hydrogen Intensity Mapping Experiment, or CHIME, in British Columbia. Astronomers reported the discoveries at a meeting of the American Astronomical Society on January 7 and in the Jan. 9 Nature. Most such bursts erupt once, last for a few milliseconds, and are never seen again. So astronomers have puzzled over what causes them for years (SN: 8/9/14, p. 22).
“If you have something that flashes for a millisecond in the sky, and there’s nothing that happens for many years, it’s really hard to study,” says astronomer Shriharsh Tendulkar of McGill University in Montreal, a member of the CHIME team.
But then in 2016, astronomers discovered the first repeating FRB when they realized that a series of bursts all came from a single source, called FRB 121102 (SN: 4/2/16, p. 12). Astronomers tracked the signal to its host galaxy (SN: 2/4/17, p. 10) and determined it was coming from an extremely magnetic environment, such as the region surrounding a black hole (SN: 2/3/18, p. 6). Researchers didn’t know if FRB 121102’s repeating signal was unique. Of the more than 60 FRBs detected, no other was known to repeat — until now. Having spotted a second one, scientists are searching for more.
“Imagine you saw a unicorn,” Tendulkar says. “Then suddenly you discover another one. You know now there is a population of these. There is hope for discovering a lot more.” The CHIME team detected the first of the repeating FRB signals on August 14, with four more coming over the next two months from the same spot on the sky. It wasn’t until the third burst, on September 17, that the team realized they might have a repeater, Tendulkar says.
“Somebody pointed out, hey look, these three bursts seem to have the same properties,” he says. “Everybody got really excited.”
Calculations show that the new repeater is about 1.6 billion light-years away. The CHIME team also saw an odd similarity between the two known repeating bursts. Most FRBs are just a sharp blip, akin to a single note being played on a trumpet. But some of the individual bursts in both repeaters were made up of multiple sub-bursts that descended in frequency, like the “wah wah wah wah” of a sad trombone.
“We’ve seen this in 121102, and we can’t explain it,” says astronomer Emily Petroff of ASTRON, the Netherlands Institute of Radio Astronomy, who was not involved in the new work. “Up until now we’ve only had the one repeater, and it’s given us more questions than answers.” But the fact that both repeaters behave similarly could suggest they have similar origins, she says.
Astronomers may have already caught a third repeating burst, too. FRB 110523, discovered in 2015, has some similar features to the first known repeating FRB, so it was worth checking to see if it also repeats, said astronomer Allison McCarthy of the University of Alabama in Tuscaloosa.
Together with Andrew Seymour of the Green Bank Observatory in West Virginia, McCarthy analyzed more than 41 hours of observations of FRB 110523 taken at the Arecibo Observatory in Puerto Rico. They found one potential repeat burst, McCarthy reported January 9 in a poster at the AAS meeting, but they’re not declaring victory just yet. “It wasn’t strong enough for us to be very sure we had detected one,” McCarthy said, adding that they’re about 60 percent certain. “But it’s still a promising candidate.”
Astronomers’ theories for what causes FRBs are almost as numerous as known FRBs themselves. At one point, astronomers even considered the idea that FRBs could be signals from intelligent aliens. But it’s unclear if the repeating bursts and single bursts both come from the same kinds of sources, or even if one-offs might also repeat if watched for long enough.
“It’s the wild, wild west out there,” Tendulkar says. “We have tantalizing clues, but it’s hard to make definitive conclusions.”
CHIME is likely to catch a lot more of these fast radio bursts. The telescope was still being tested when it caught the 13 new ones, so was not operating at peak performance. “They just barely turned on the telescope,” Petroff says, “and they’re already finding things.”
SAN FRANCISCO — Seizures during sleep can scramble memories — a preliminary finding that may help explain why people with epilepsy sometimes have trouble remembering.
The sleeping brain normally rehashes newly learned material, a nocturnal rehearsal that strengthens those memories. Neuroscientist Jessica Creery and her colleagues forced this rehearsal by playing certain sounds while nine people with epilepsy learned where on a screen certain pictures of common objects were located. Then, while the subjects later slept, the researchers played the sounds to call up some of the associated memories.
This sneaky method of strengthening memories, called targeted memory reactivation, worked as expected for five people who didn’t have seizures during the process. When these people woke up, they remembered the picture locations reactivated by a tone better than those that weren’t reactivated during sleep, said Creery, of Northwestern University in Evanston, Ill. She presented the research March 25 at the annual meeting of the Cognitive Neuroscience Society.
The opposite was true, however, for four people who had mild seizures, detected only by electrodes implanted deep in the brain, while they slept. For these people, memory reactivation during sleep actually worsened memories, making the reactivated memories weaker than the memories that weren’t reactivated during sleep. The combination of seizures and memory reactivation “seems like it’s actually scrambling the memory,” Creery says, a finding that suggests that seizures somehow accelerate forgetting.
A few months back, a new storefront appeared in my small Oregon town. Its shelves were packed with tinctures, jars of salve, coffee beans, bath bombs — even beard oil. This motley collection shared a single star ingredient: CBD.
Produced by the cannabis plant, CBD is the straitlaced cousin of marijuana’s more famous component — the THC that delivers a mind-swirling high. CBD, or cannabidiol, has no such intoxicating effects on the mind. Yet the molecule has captured people’s attention in a profound way, sold as a remedy for pain, anxiety, insomnia and other ailments — all without the high.
That neighborhood shop, CBD Scientific, is far from alone in its efforts to sell people on the benefits of CBD, which is found in both marijuana and hemp, two versions of the Cannabis sativa plant. CBD is popping up in products in pet stores, coffee shops and the health and beauty sections of mainstream grocery stores. It’s even being brewed into beer. I left the shop with a $5 bottle of water infused with “5,000,000 nanograms” of CBD.
So far, messages of CBD’s purported health benefits come from people trying to sell CBD products — not from scientists, says Margaret Haney, a neurobiologist who directs the Marijuana Research Laboratory at Columbia University. A gaping chasm separates the surging CBD market and the scientific evidence backing it. While there are reasons to be excited about CBD, the science just isn’t there yet, Haney says. Scientists still don’t know all of the targets CBD hits in the human body, nor what effects it may have, if any. With the exception of tests in people with rare forms of epilepsy, large studies that compare CBD with placebos in people are rare. Much of the existing research was done with cells in the lab or in lab animals, with results that don’t necessarily translate to people.
And there’s always the chance that for some people, CBD’s magic is made not by the compound itself but by a powerful placebo effect; people who expect good outcomes are more likely to see benefits.
Researchers are stepping into the void, lured by promising early data. Small trials are under way looking at the effect of CBD on anxiety, pain, opioid addiction, depression and other health problems. National Institutes of Health funding for CBD studies went from zero in 2014 to an estimated $16 million in 2018. “We’re very interested in CBD,” says Susan Weiss, director of the Division of Extramural Research at the National Institute on Drug Abuse in Bethesda, Md. Still, she urges caution to people eager to try CBD. Because of lax oversight, there’s no telling what’s inside many of those tinctures, oils, rubs and foods for sale online and in stores. “A lot of the products that people are taking may not be what they think,” she says.
Despite the risks and warnings, it seems safe to say that the collective fascination with CBD isn’t going to wear off anytime soon. “People think it’s great for everything,” says cognitive neuroscientist Kent Hutchison of the University of Colorado Boulder. That can’t possibly be true, he says. “But I do think it’s going to be great for some things. We just need to figure out what those things are.”
Mystery molecule Each morning, Samantha Montanaro of Portland, Ore., drops a CBD tincture under her tongue. “I’m kind of testing out my own body with this,” she says. “I’m finding that it really helps with anxiety and stress.”
Montanaro isn’t alone; CBD testimonials are increasingly easy to find. In 2016, Montanaro, now 35, cofounded Tokeativity, a global cannabis community for women. Back then, “CBD wasn’t even a thing,” she says. But the first sparks of the CBD movement caught fire fast. “It’s been pretty crazy to watch how things have evolved,” she says. Some bullish analysts predict that the CBD market in the United States will balloon from hundreds of millions of dollars in 2018 to almost $20 billion by 2022.
Ziva Cooper directs UCLA’s Cannabis Research Initiative and fields a lot of questions about CBD. Her answers invariably disappoint. “When I tell [people] we don’t have very much evidence in people, they’re actually surprised,” she says. When it comes to CBD’s benefits, “there’s actually very little out there to hang our hats on.”
The one exception is for rare forms of childhood epilepsy. Neurologist Elizabeth Thiele of Massachusetts General Hospital in Boston had a young patient who was having over 100 seizures a day. After other treatments had failed, the boy’s parents began searching for a source of CBD oil, which they desperately wanted to try after learning about promising early results in animals. The family flew to England, so the boy could try the CBD formulation made by GW Pharmaceuticals. The child’s results, Thiele says, were remarkable. After a week of CBD, his daily seizures had fallen to single digits. That result ultimately led to clinical trials, one of which included 171 people, mostly children, with Lennox-Gastaut syndrome, a rare and severe seizure disorder. In addition to their normal medication, half of the participants got doses of CBD that were rigorously tested and standardized by the drug’s maker. The other half received their regular treatment plus a placebo. After 14 weeks, the people taking CBD saw a median drop in monthly seizure frequency of about 44 percent; seizures in people who took the placebo dropped almost 22 percent. Thiele and her colleagues published those results in March 2018 in the Lancet.
Side effects were manageable, the researchers found. Diarrhea, sleepiness, poor appetite and vomiting were more likely to occur in the people who took CBD than in those who got the placebo. Along with results from several other trials, those data were strong enough to prompt the U.S. Food and Drug Administration to approve the CBD drug, called Epidiolex, last June. Despite rigorous testing of Epidiolex, big gaps in knowledge on how the drug works in epilepsy remain. Researchers don’t know how CBD tames seizures. Because the molecule comes from cannabis, the early assumption was that CBD latches onto the same chemical receptors that THC connects to, one primarily in the brain and one mainly on immune cells. It turns out, however, that CBD doesn’t seem to hit either of those receptors.
Instead, studies in rats and mice point to two different targets. One, called TRPV1, is known to play a role in pain sensation and maybe epilepsy, too. The other, called GPR55, might change the activity level of nerve cells in the brain, a feat that may be behind CBD’s antiseizure power.
Scientists also don’t know whether CBD keeps working year after year. For some of Thiele’s patients, CBD seems to still be effective after five years of taking the drug, even allowing them to taper off some of their other medications, she says. But data from 92 other patients, presented in December at the American Epilepsy Society’s annual meeting, suggest that CBD’s benefits can start to fade after about seven months on the drug. About a third of the people in the study needed a dose increase after their CBD doses became less effective, researchers from Tel Aviv Sourasky Medical Center reported.
Research on CBD and other ailments lags way behind the epilepsy work. Early experiments, mostly on lab animals but some in small numbers of people, suggest that CBD might fight anxiety, ease schizophrenia symptoms and address pain.
One example: Healthy men who took CBD before a stressful public speaking task were calmer than those who took a placebo, researchers reported in October in the Brazilian Journal of Psychiatry. But only the 15 men who received doses of 300 milligrams were more relaxed. The 27 who took less or more CBD didn’t see benefits. Other types of studies with people, and studies of mice and rats, have turned up antianxiety effects, too. But most of these studies looked at single doses of CBD, not consistent use.
Early evidence of CBD’s promise against schizophrenia comes from a trial of 88 people with the disorder. After six weeks, people who had received a big daily dose of CBD (1,000 milligrams a day) in addition to their normal medication had more improvements in certain symptoms when compared with people who received a placebo. Those results hint that CBD might be a new type of drug for schizophrenia, researchers wrote in March 2018 in the American Journal of Psychiatry.
Studies in lab animals suggest that CBD may help relieve chronic pain. A study appearing in 2017 in Pain found that CBD could block osteoarthritis pain and nerve damage in rats. Hard data for humans are harder to find, but anecdotes abound. Pain clinician Kimberly Mauer of Oregon Health & Science University in Portland and colleagues at the OHSU Comprehensive Pain Center have seen an uptick in patients who say they’re taking CBD. Their experiences are mixed, she says: “About half the patients say they get some benefit, and about half say they didn’t notice anything.”
No easy access To answer the many outstanding questions about CBD’s effects, scientists need access to the compound. But a complex web of U.S. regulations makes that difficult. CBD is subject to rules from both the FDA and the U.S. Drug Enforcement Administration. CBD produced by the marijuana plant remains on the DEA’s list of the most restrictive class of drugs, Schedule 1, alongside LSD, ecstasy and other drugs deemed to have no accepted medical use and high potential for abuse. Access restrictions on industrial hemp, and by extension, the CBD that comes from hemp, were eliminated in the 2018 Farm Bill, signed into law in December. However, regardless of its provenance, CBD is still subject to FDA regulations, as well as any regulations imposed by states. “As easy as it’s gotten for the average person to go legally to buy recreational marijuana and consume it in many states, it’s gotten harder for scientists,” says Haney at Columbia. One of the few approved sources of CBD is a government-sanctioned cannabis facility at the University of Mississippi in Oxford. After she gets the CBD she needs for her studies, Haney is required to meticulously account for every milligram. “I have a gun safe in a locked room that I get into with my fingerprints to store both cannabidiol and marijuana.”
With those restrictions, many scientists just can’t do the studies they want, Hutchison says. “The whole thing is a little bit crazy. People can sell it everywhere, but it’s very difficult for scientists to study its effects in humans.”
Hutchison and colleagues have figured out a legal work-around that doesn’t require researchers to obtain supplies of CBD. The team is avoiding the government-grown cannabis, which can be quite different from the products in circulation, by testing the effects of the cannabis products that people are actually using. To do this, the researchers created a mobile pharmacology lab they call the CannaVan. The tricked-out Dodge contains equipment to study people after they’ve taken a product containing CBD (or THC) that they bought themselves. The researchers are currently collecting data on CBD’s effects on anxiety and pain. Buyer beware FDA rules say that CBD cannot be legally added to food and sold across state lines, sold as a dietary supplement or marketed with claims of treating diseases. But aside from sending some warning letters, the FDA has, so far, let the marketplace run uninhibited. (Some local health authorities, however, are beginning to flex their might, warning restaurants in New York City, for instance, to take CBD off the menu.)
Overall, no one really knows what’s inside the bottles, rubs and coffees for sale. A study published in 2017 in JAMA gives a sense of the problem. Researchers ordered and tested 84 products sold online in 2016 as CBD-containing products. Of those, only 26 were labeled accurately (containing CBD within 10 percent of the claimed amount); 36 of the products had more CBD than their labels said; and 22 products had less. The researchers also found THC in 18 of the 84 samples. Sophie Cloyd is a 30-year-old manager for the CBD company Ablis of Bend, Ore. She is also pregnant. I met her recently at a ski lodge, where she was offering beverage tastes and describing tinctures, oils and lotions. CBD, she says, has helped her manage this pregnancy, her second. She was prescribed the anti-nausea drug Zofran early in her pregnancy, but “the research on Zofran scared me more than the lack of research on CBD,” she says.
Ablis, which makes CBD-infused fizzy drinks and other products, currently gets purified CBD from Colorado, Cloyd says. When the CBD arrives, the company sends it to an independent lab to confirm that it has the right amount of CBD, no pesticides and no THC. But not all CBD sellers test their products.
An unexpected THC dose might not be enough to get a user high, but it could still be a problem, as news reports have begun to point out. To ease his pain from psoriatic arthritis, a school bus driver in Beaverton, Ore., had been taking a daily dose of CBD oil. In early 2018, he failed a periodic drug test with high THC levels, which caused him to lose his job, Portland news channel KATU reported. Even seemingly small amounts of THC can build up in the body with repeated use.
A product might contain even worse surprises. Between December 2017 and January 2018, for example, 52 people fell ill in Utah, with symptoms such as hallucinations, vomiting and seizures, after taking what they thought was CBD. It turned out that the products, many labeled “Yolo CBD oil,” contained a synthetic cannabinoid, and it had poisoned them.
Even if product labels were always accurate, people have no idea of the correct dose of CBD (assuming the right dose would be effective). “You see it marketed in doses like 10 milligrams,” Hutchison says. “Well, 10 milligrams probably does nothing.” For comparison, people who participated in one Epidiolex study took 20 milligrams per kilogram of body weight. To reach that daily dose, I’d need to chug 254 bottles of that 5 million nanogram CBD water I bought — at a cost of $1,270.
Haney makes the same point: “You’re not getting anything resembling an effective dose when you get CBD added to your coffee, or you buy a mint with a little bit of CBD in it,” she says.
There’s even less known about CBD products that you rub on your skin. Scientists don’t know that CBD in creams, oils and ointments actually makes it into the body. “I’m not convinced that anything you’re rubbing on your body with CBD is even getting through,” Haney says. At its heart, the trouble is that most CBD use isn’t backed up by science, Haney says. “I am not against CBD,” she says. In fact, she is about to start a study looking at CBD to treat nerve pain due to chemotherapy in cancer patients. “But I don’t like marketers determining what it’s good for and what it’s not.”
Hype run amok isn’t anything new, says Mauer, the OHSU pain doctor. Consumers try lots of things before the science is definitive — keto diets, for instance, or vitamin D supplements (SN: 2/2/19, p. 16). And even if it turns out that the chemical doesn’t work, the placebo effect might be enough to help reduce symptoms.
So far, the science on CBD isn’t mature enough to weigh in, one way or another. But judging by the number of studies and clinical trials under way, this nascent research field is growing up fast, seeking to quickly fill the space between the science and what people want to know.
This research boom heartens Montanaro. Her message to the scientific community: “I would encourage curiosity,” she says. “I’m not a doctor, and I’m not a scientist, but I certainly know my own body,” and she says that CBD helps her. From her perspective, science has got some catching up to do.
This story appears in the March 30, 2019 issue of Science News with the headline, “The Allure of CBD: People seek health benefits despite lack of evidence.”
