Here’s one good reason why people often take medications and use health products that don’t live up to expectations or just don’t work — digital word of mouth.

The reviews can be glowing. Take this scuttlebutt about a cholesterol treatment: “I have been using this product for 2 years. Within the first 3 – 4 months my cholesterol was down 30 points. Just got cholesterol tested last week: down from 245 to 196.”

That’s incredible. It might even be true. But the big picture is alarming: Patients’ online reviews of three over-the-counter drugs — two for lowering cholesterol and one for losing weight — greatly exaggerate how well these substances actually work for most people, says psychologist Mícheál de Barra of the University of Aberdeen in Scotland. Online reviewers portray these medications as working three to six times better than they do in clinical trials that randomly assign drugs or placebos to broad samples of volunteers, he says.

“To learn what works in medicine, you need systematically collected data, usually randomized clinical trials,” de Barra says. “It’s very risky to rely on observations and word of mouth, whether it’s electronic or in person.”

Online reviewers probably aren’t lying, at least not in most cases. Neither are online review readers unrealistically optimistic about health treatments. The problem is that people who benefit most from a medication are especially apt to post their experiences online. Review readers get bamboozled by a wave of positive recommendations that don’t accurately represent how a drug works, or doesn’t work, for people in general.

The duping doesn’t end there. Direct word of mouth about medical treatments, as well as glowing testimonials about health products in advertisements, also traffic in positively skewed information.

In some cases, science does, too. Researchers have recently raised alarms about the “file-drawer problem,” in which studies that find no statistical effects are not published (SN: 5/19/12, p. 26). Published studies reporting positive effects then look unjustifiably bulletproof.

Clinical trials can tilt results in other ways as well. Authors of published trials often fail to preregister details of what they plan to study and how they’ll measure it, enabling data manipulation, selective reporting of results and self-serving interpretations of findings. Clinical trials report patients’ “average” responses to, say, an anticholesterol drug, but do a poor job of predicting which individuals will benefit from that treatment. “Published evidence from randomized trials is already an amalgam of evidence-based medicine and hearsay,” notes Stanford University epidemiologist John Ioannidis.
Online reviews are just old-fashioned word of mouth with a global bullhorn. But they offer one way to quantify the positive bias inherent in so much communication about medical treatments. Patients’ medication reviews that include numerical information, such as cholesterol levels before and after taking an anticholesterol drug, represent what Ioannidis calls “evidence-based hearsay.” Even if patients’ reviews rate treatments with a star system rather than including quantified measures of some kind, those opinions become powerful hearsay evidence for other patients, Ioannidis suspects.

De Barra evaluated 908 online reviews of two cholesterol reduction products, Benecol caramel smart chews and CholestOff, written on or before March 18, 2015. He also assessed 767 reviews of a weight-loss drug, Alli (orlistat), written on or before February 28, 2015.

Benecol reviewers reported a not-too-shabby average cholesterol decline of 45 milligrams per deciliter, versus a small average decline of 14 milligrams per deciliter in nine clinical trials. Respective numbers for CholestOff were 31 milligrams per deciliter and 13 milligrams per deciliter. Alli reviewers reported an average weight loss of about 10 kilograms after taking the drug for three months, versus an average of about two or three kilograms in two clinical trials. That disparity widened slightly after taking Alli for seven months.

Each drug garnered mainly positive reviews, some reporting effects far larger than the average, peppered with a few pans, De Barra reports in the March Social Science & Medicine.

What’s particularly concerning is that these three medications displayed small or negligible effects in clinical trials that probably already inflated how well the drugs work, Ioannidis says. So people searching for help in lowering cholesterol or shedding pounds may instead be getting a massive dose of disappointment from online reviews.

Online reviews can also exaggerate a treatment’s worst effects, whether real or alleged. Evidence-based hearsay may be particularly catchy online and in person when it’s frightening, de Barra suspects.

The anti-vaccination movement provides a potent example, due in part to the success of vaccines. When people face no immediate threat from measles or other infectious diseases, anti-vaccine stories may go viral, so to speak, thanks to misapplied but deeply felt intuitions. Two cognitive scientists, Helena Miton of Central European University in Budapest and Hugo Mercier of the Cognitive Sciences Institute in Bron, France, proposed this scenario in the November 2015 Trends in Cognitive Sciences.

However medical treatments acquire halos or horns, only well-conducted, transparent clinical trials can identify effective medical treatments, such as childhood vaccinations, and their potential side effects, Ioannidis says. But an ominous research trend is gathering steam, he warns. Researchers, professional societies, funders and lobbyists increasingly push to replace clinical trials of randomly selected volunteers with studies of interventions for select samples of people who eat certain foods, take certain drugs or behave in certain ways. The latter investigations may inflate a treatment’s effects even more than online patient reviews do, Ioannidis asserts.

Perhaps a new wave of studies showing how evidence-based hearsay misrepresents many medications will be just what the doctor ordered to resuscitate evidence-based medicine, he muses.

Remnants of a royal palace in southern Mexico, dating to between around 2,300 and 2,100 years ago, come from what must have been one of the Americas’ earliest large, centralized governments, researchers say.

Excavations completed in 2014 at El Palenque uncovered a palace with separate areas where a ruler conducted affairs of state and lived with his family, say archaeologists Elsa Redmond and Charles Spencer, both of the American Museum of Natural History in New York City. Only a ruler of a bureaucratic state could have directed construction of this all-purpose seat of power, the investigators conclude the week of March 27 in Proceedings of the National Academy of Sciences.

The royal palace, the oldest such structure in the Valley of Oaxaca, covered as many as 2,790 square meters, roughly half the floor area of the White House. A central staircase connected to an inner courtyard that probably served as a place for the ruler and his advisors to reach decisions, hold feasts and — based on human skull fragments found there — perform ritual sacrifices, the scientists suggest. A system of paved surfaces, drains and other features for collecting rainwater runs throughout the palace, a sign that the entire royal structure was built according to a design, the researchers say.

El Palenque’s palace contains no tombs. Its ancient ruler was probably buried off-site, at a ritually significant location, Redmond and Spencer say.

A new species of worm-snail is rather snotty. Thylacodes vandyensis shoots out strands of mucus that tangle together, building a spiderweb-like trap for plankton and other floating snacks, researchers report April 5 in PeerJ.

Other worm-snails use this hunting technique, but T. vandyensis stands out because of the “copious amounts of mucus” it ejects, says coauthor Rüdiger Bieler. This goo net, which can stretch up to 5 centimeters across, exits the animal’s tentacles at, of course, “a snail’s pace,” jokes Bieler, a curator at the Field Museum of Natural History in Chicago.

Like other worm-snails, T. vandyensis permanently glue themselves to spots. Bieler found T. vandyensis, which typically grow half as tall as a pinkie finger, on the hull of a sunken ship in the Florida Keys. But they don’t belong there: DNA analysis shows that this invasive species’ closest relatives are in the Pacific Ocean. The worm-snail may have made its way to the Atlantic as a stowaway on a ship.

Egyptian mummies are back in style at the summer box office — and in genetics labs. A study of genetic blueprints from 90 mummies repairs the frayed reputation of sarcophagus occupants as sources of ancient DNA. And it reveals evidence of a hookup history with foreigners from the east.

An Egyptian mummy served up the first ancient human DNA sample in 1985 (SN: 4/27/85, p. 262). But both chemicals used in mummification and Egypt’s steamy climate can degrade DNA, and scientists weren’t sure if mummies could supply samples free of modern contamination.

Carefully screening for quality and using the latest in sequencing tech, Verena Schuenemann of the University of Tübingen in Germany and her colleagues extracted and analyzed mitochondrial DNA, which passes from mom to child. They worked primarily with samples from teeth and bones, rather than from soft tissue. Three mummies yielded readable samples of DNA from cell nuclei, which includes DNA from both parents. The mummies ranged in age of origin from 1388 B.C. to A.D. 426.

The analysis reveals genetic ties to the Middle East and Greece — not a huge surprise since Egypt was a center of travel and trade at that time. The conspicuous absence of genetic connections to sub-Saharan Africa seen in modern Egyptians points to a later influx of foreigners from that region, the researchers write May 30 in Nature Communications.

Imagine for a moment that you lived on another planet. Not Tatooine, Trantor or another fictional orb, but a real-deal planet circling a star somewhere in our real-deal galaxy. What would your world look like? Would there be a rocky surface? An atmosphere? How long would a day last? How about a year? What special physiology might you need to survive there? There’s no single scenario, of course. Starting with some basic facts, you can speculate in all sorts of surprising directions. That’s the fun of the exercise.

Over the last quarter century or so, astronomers have confirmed more than 3,600 exoplanets — that’s 3,600-plus worlds in addition to the planets, moons and other heavenly bodies known in our own solar system. People have long imagined what it would be like to live on Mars, and bold thinkers have dared to envision an existence on, say, Jupiter (see “Juno spacecraft reveals a more complex Jupiter“). Today there are many more possibilities, including planets orbiting dim red stars very different from our sun. In “Life might have a shot on planets orbiting dim red stars,” Christopher Crockett describes the hurdles life might face in evolving and surviving near these cool stars. On planets orbiting Proxima Centauri, TRAPPIST-1 and other M dwarfs, water could be extremely sparse, energetic flares might regularly singe the surface and you might live always in sun or forever in darkness.
Reading about these worlds, I’d say, is better than fiction — as is a lot of what Science News covers. You don’t need a novel or a movie to escape into what feels like another reality. Just flip through these pages. The stories will take you to other worlds, as well as inner, hidden ones. Former Science News intern Elizabeth S. Eaton writes about the bacteria that infect our bodies and the problem of antibiotic resistance. Picturing these invisible, single-celled organisms wreaking havoc in the body, unchecked by our best medicines, gives me goose bumps. Eaton’s story is about the battle that would ensue if predatory bacteria are sent in to hunt down and kill these bad guys, as some researchers have proposed. One researcher likens the bacteria to the antagonists in the Alien films. There’s true cinematic potential.

And it doesn’t end there. Bruce Bower takes readers into the past, to the roots of the human evolutionary tree. Most scientists think Africa was the birthplace of hominids, but new research suggests it could have been Europe. And Susan Milius offers an opportunity to consider what it might be like to live in another type of body — a flamingo’s. The birds have an off-kilter shape, with ankles where we’d expect knees. For flamingos, Milius reports, standing on one leg might be more stable than standing on two. After reading the story, I couldn’t help but attempt to balance on just my right foot, in hopes of getting a handle on human-flamingo differences. (It was an unsuccessful 20 seconds. Thank goodness my office door was closed.)

Every issue of Science News includes similar inspiration. There’s serious stuff to be sure, but there are plenty of chances to ponder the strangeness of reality — and to stretch it. After thinking about living on Proxima b or being a wading bird, consider being a wading bird on Proxima b. For fuel to help your imagination run, you’ve come to the right place.

A newly discovered glass frog from Ecuador’s Amazon lowlands is giving researchers a window into its heart.

Hyalinobatrachium yaku has a belly so transparent that the heart, kidneys and urine bladder are clearly visible, an international team of researchers reports May 12 in ZooKeys. Researchers identified H. yaku as a new species using field observations, recordings of its distinct call and DNA analyses of museum and university specimens.

Yaku means “water” in Kichwa, a language spoken in Ecuador and parts of Peru where H. yaku may also live. Glass frogs, like most amphibians, depend on streams. Egg clutches dangle on the underside of leaves, then hatch, and the tadpoles drop into the water below. But the frogs are threatened by pollution and habitat destruction, the researchers write. Oil extraction, which occurs in about 70 percent of Ecuador’s Amazon rainforest, and expanding mining activities are both concerns.

Winter weather brings seismic tremors. A new study reveals how water buildup and runoff throughout the year can increase stress along faults in California, triggering small earthquakes.

“This kind of observation is extremely important to constrain our models of earthquakes,” says Jean-Philippe Avouac, a geologist at Caltech who was not involved in the study. Improved models could ultimately help scientists better forecast seismic activity.

Snow and rain compress mountain ranges in Northern California several millimeters during wet winter months. But with the weight of the water gone during the dry summers, the landscape lifts back up. This seasonal squeeze and release of the terrain puts stress on nearby faults, which can set off more small earthquakes.
Researchers compared observations of ground movement from 661 GPS stations in California with the state’s earthquake record from 2006 to 2014. The landscape’s seasonal, water-induced rise and fall corresponded to periodic increases in small quakes, scientists report in the June 16 Science. Most of the quakes were between magnitude 2 and 3 — so small that they wouldn’t have been widely felt, says study coauthor Christopher Johnson, a seismologist at the University of California, Berkeley.
“It’s not like there’s an earthquake season,” Johnson says. Some faults experience more significant stress increases when the land is compressed, others when the land rebounds, depending on the fault orientation. So different faults exhibit more small earthquakes at different times of year. For instance, faults along the Sierra Nevada’s eastern edge have more tremors in late winter and early spring. But the San Andreas Fault system to the west sees more quakes in late summer and early fall, when water levels have dropped and the land is rebounding.

“We’re not yet at the point where we could start applying this knowledge to the hazard forecast,” Johnson says. But the new findings are helping geologists better understand what forces can trigger rumbles under our feet.

As if air travel weren’t annoying enough, new research suggests that global warming could force planes to carry fewer passengers to get off the ground. While a little more legroom might sound good, it could make flying more expensive.

Researchers examined the impact of rising temperatures on five types of commercial planes flying out of 19 of the world’s busiest airports. In the coming decades, an average of 10 to 30 percent of flights that take off during the hottest time of day could face weight restrictions.

That’s because warmer air particles are more spread out, generating less lift under a plane’s wings as it goes down the runway. So a plane must be lighter to take off. In some cases, a Boeing 737-800 would have to jettison more than 700 pounds — several passengers’ worth of weight — the researchers report online July 13 in Climatic Change.

When faced with rushing floodwaters, fire ants are known to build two types of structures. A quickly formed raft lets the insects float to safety. And once they find a branch or tree to hold on to, the ants might form a tower up to 30 ants high, with eggs, brood and queen tucked safely inside. Neither structure requires a set of plans or a foreman ant leading the construction, though. Instead, both structures form by three simple rules:

If you have an ant or ants on top of you, don’t move.
If you’re standing on top of ants, keep moving a short distance in any direction.
If you find a space next to ants that aren’t moving, occupy that space and link up.
“When in water, these rules dictate [fire ants] to build rafts, and the same rules dictate them to build towers when they are around a stem [or] branch,” notes Sulisay Phonekeo of the Georgia Institute of Technology in Atlanta. He led the new study, published July 12 in Royal Society Open Science.

To study the fire ants’ construction capabilities, Phonekeo and his Georgia Tech colleagues collected ants from roadsides near Atlanta. While covered in protective gear, the researchers dug up ant mounds and placed them in buckets lined with talc powder so the insects couldn’t climb out. Being quick was a necessity because “once you start digging, they’ll … go on attack mode,” Phonekeo says. The researchers then slowly flooded the bucket until the ants floated out of the dirt and formed a raft that could be easily scooped out.

In the lab, the researchers placed ants in a dish with a central support, then filmed the insects as they formed a tower. The support had to be covered with Teflon, which the ants could grab onto but not climb without help. Over about 25 minutes, the ants would form a tower stretching up to 30 mm high. (The ants themselves are only 2 to 6 mm long.)
The towers looked like the Eiffel Tower or the end of a trombone, with a wide base and narrow top. And the towers weren’t static, like rafts of ants are. Instead, videos of the ant towers showed that the towers were constantly sinking and being rebuilt.

Peering into the transparent Petri dish from below revealed that the ants build tunnels in the base of a tower, which they use to exit the base before climbing back up the outside.

“The ants clear a path through the ants underneath much like clearing soil,” Phonekeo says. Ants may be using the tunnels to remove debris from inside the towers. And the constant sinking and rebuilding may give the ants a chance to rest without the weight of any compatriots on their backs, he says.

To find out what was happening inside the tower, the researchers fed half their ants a liquid laced with radioactive iodide and then filmed the insects using a camera that captured X-rays. In the film, radioactive ants appeared as dark dots, and the researchers could see that some of those dots didn’t move, but others did.

The team then turned to the three rules that fire ants follow when building a raft and realized that they also applied to towers. But there was also a fourth rule: A tower’s stability depends on the ants that have attached themselves to the rod. The top row of ants on the rod aren’t stable unless they form a complete ring. So to get a taller tower, there needs to be a full ring of ants gripping to the rod and each other.

That such simple rules could form two completely different structures is inspiring to Phonekeo. “It makes me wonder about the possibilities of living structures that these ants can build if we can design the right environment for them.”

After five years on Mars, the Curiosity rover is an old pro at doing science on the Red Planet. Since sticking its landing on August 5, 2012, NASA’s Little Robot That Could has learned a lot about its environs.

Its charge was simple: Look for signs that Gale crater, a huge impact basin with a mountain at its center, might once have been habitable (for microbes, not Matt Damon). Turning over rocks across the crater, the rover has compiled evidence of ancient water — a lake fed by rivers once occupied the crater itself — and organic compounds and other chemicals essential for life.
NASA has extended the mission through October 2018. And there’s still plenty of interesting chemistry and geology to be done. As the robot continues to climb Mount Sharp at the center of the crater, Curiosity will explore three new rock layers: one dominated by the iron mineral hematite, one dominated by clay and one with lots of sulfate salts.

So, here are four Martian mysteries that Curiosity could solve (or at least dig up some dirt on).

Does Mars harbor remnants of ancient life?
Curiosity’s Mars Hand Lens Imager can take microscopic images, but preserved cells or microfossils would still have to be pretty big for the camera to see them. What the rover can do is detect the building blocks for those cells with its portable chemistry lab, Sample Analysis at Mars. The lab has already picked up chlorobenzene, a small organic molecule with a carbon ring, in ancient mud rock. Chains of such molecules go into making things like cell walls and other structures.
“We’ve only found simple organic molecules so far,” says Ashwin Vasavada, a planetary scientist at NASA’s Jet Propulsion Laboratory who leads Curiosity’s science team. Detective work in chemistry labs here on Earth could shed light on whether bigger organic molecules on Mars’ surface might degrade into smaller ones like chlorobenzene.

Curiosity could still turn up intact, heavier-duty carbon chains. The rover carries two sets of cups to do chemistry experiments, one dry and one wet. The latter contains chemical agents designed to draw out hard-to-find organic compounds. None of the wet chemistry cups have yet been used. A problem with Curiosity’s drill in December 2016 has held up the search for organics, but possible solutions are in the works.
How did Mars go from warm and wet to cold and dry?
That’s one of the million-dollar questions about the Red Planet. Curiosity has piled on evidence that Mars was once a much more hospitable place. Around 3.5 billion years ago, things changed.

The going theory is that particles from the sun stripped away much of Mars’ atmosphere (and continues to do so) when the planet lost most of its protective magnetic field. “That caused the climate to change from one that could support water at the surface to the dry planet it is today,” Vasavada explains. Curiosity found a higher ratio of heavy elements in the current atmosphere, adding credence to this argument — presumably the lighter elements were the first to go.

There’s also a chance that as the rover hikes up Mount Sharp it could capture regional evidence of the wet-to-dry transition. So far, Curiosity has investigated rocks from the tail end of the wet period. The new geologic layers it will encounter are younger.

“Hopefully we’ll be able to get some insight by looking at these rocks into some of the global changes happening that maybe no longer permitted a lake to be present on the surface,” says Abigail Fraeman, a research scientist at NASA’s Jet Propulsion Lab.
Does Mars really have flowing water today?
Some mineralized salts absorb water and release it as liquid when they break down at certain temperatures. The Curiosity team looked for the bursts of water that might result from such a process in Gale crater and came up empty.

But in 2015, the Mars Reconnaissance Orbiter snapped images of shifting salt streaks indicative of actively flowing water. The images are the best evidence yet that liquid water might not be a thing of the past.

Mount Sharp has similar dark streaks, and Curiosity periodically takes pictures of them. “It’s something we keep an eye on,” Vasavada says. If the streaks change in a way that might indicate that they’re moving, the rover could corroborate evidence of modern-day water on Mars. But so far, the streaks have stayed stagnant.

Where does the methane in Mars’ atmosphere come from?
On Earth, microbes are big methane producers, but on Mars, methane’s origins are still unclear. Early on Curiosity detected extremely low levels of the gas in Mars’ atmosphere. This baseline appears to subtly fluctuate annually — perhaps driven by temperature or pressure. Curiosity continues to monitor methane levels, and more data and modeling could help pinpoint what’s behind the annual ups and downs.

At the end of 2014, researchers noticed a spike 10 times the baseline level. Scientists suspect that methane sticks around in the air on Mars for only about 300 years. So, the methane spike must be relatively new to the atmosphere. “That doesn’t necessarily mean it’s being actively created,” Vasavada says. “It could be old methane being released from underground.” Minerals interacting with subterranean water sometimes make methane gas.

Mars’ methane could also be the product of planetary dust particles broken down on the surface. And yet another possible explanation is biological activity. “We have zero information to know whether that’s happening on Mars, but we shouldn’t exclude it as an idea,” says Vasavada. So, Martian life is unlikely but can’t be completely ruled out.