As income rises, the frequency of fast food visits rise as well, at least until income hits $60,000 a year; sit-down restaurant visits just keep on rising. (The y axis is frequency of visits.)

Obesity rates in the United States are highest among the poor, and high up on most lists of reasons why, you’ll find the truism that fast food is cheap food, and the poor, who can’t afford healthier fare, are its main consumers. A new study suggests, however, that the people eating the most fast food are middle class, with incomes as high as $60,000 a year. Using a national database of about 5,000 people, researchers at UC Davis found that the frequency of people’s visits to fast-food restaurants increased with rising household income until $60,000, when frequency started to go down (though, interestingly, people making more than $100,000 still went to fast food more than those making $20,000). Visits to sit-down restaurants, on the other hand, increased with rising income and just kept on growing.

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What’s the News: If two South Korean researchers have their way, the days of needing specialized equipment to test whether someone has strep, the flu, or other common illnesses may soon be numbered. The pair want to check for disease markers in a tiny drop of a bodily fluid by pressing it against a touchscreen, so your diagnosis could come straight from your smart phone. While there’s no app for that yet, the scientists recently finished a proof-of-concept study showing that a touchscreen could differentiate between various concentrations of bacterial DNA—a first step towards diagnosing your disease by spitting on your iPad.

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The war between people and disease-causing pathogens is old as humanity itself. This has helped shaped our so-called behavioral immunity, which can lead us, for example, to automatically avoid people who are visibly sick. But it can also misfire; previous studies have shown that people with compromised immune systems (due to a recent illness), and even people who describe themselves as afraid of germs or susceptible to disease, are more likely to avoid and feel prejudiced toward otherwise healthy people who merely look different than them, like foreigners or immigrants.

It appears this prejudice can be reduced or erased by public health measures like vaccination or the simple act of washing your hands, according to a recent study in Psychological Science. In the study’s first experiment, conducted at the height of the 2009 H1N1 swine flu, researchers gathered a group of participants, some of whom had already received a vaccine against H1N1. They were then randomly broken into two groups, which I’ll call group A and group B (each had roughly equal numbers of vaccinated and non-vaccinated people). Group A read news articles describing the flu’s health effects and the vaccine’s effectiveness, in order to remind or “prime” them to the threat posed by the virus. Group B read no such articles. All participants then took a test that measures prejudicial attitudes towards immigrants. In group A, unvaccinated people were more prejudiced against immigrants than those who had received the vaccine. In the “unprimed” group B, there was no measurable difference.

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If you remember anything from statistics class, it’s probably that correlation ain’t no causation. Just because two numbers happen to go up at the same time doesn’t mean that one is causing the other to rise (or fall, or hold steady, or whatever). If there isn’t a plausible explanation for how the two might be connected, and proof that that explanation is indeed the cause, all you have is a couple of lines on a chart.

So it’s a move in the right direction when people try to suss out connections between two variables they have a hunch are related. But seeking such a connection can lead to some pretty convoluted reasoning. A new paper—unpublished, but released for discussion—claims that the passage of states’ medical marijuana laws cause decreased traffic fatalities, following on the researchers’ intuition that people might smoke pot instead of drinking alcohol if marijuana were more readily obtainable, and that driving while high is less dangerous than driving drunk. Their logic goes like this: if medical marijuana laws make pot more easily available, and people smoke more pot after laws are passed, and they buy less alcohol because of that, then there would be fewer traffic deaths.

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Vaccines usually work by getting the body to make antibodies against a virus, so when the virus appears on the scene, the immune system is prepared to tag it for destruction. But getting the body excited about making such antibodies isn’t always easy. It’s this stumbling block that has made HIV vaccines so disappointing so far, and in response, some scientists have reached for the big guns of biology. In a paper published today in Nature, one team reports that they’ve been able to make mice immune to HIV using, of all things, gene therapy.

Best known as a process for replacing faulty genes with fresh ones to treat chronic diseases, gene therapy seems, at first glance, like overkill. It involves engineering a lab-grown virus to permanently insert a gene into a patient’s genome, and it can be dicey, to say the least. Despite two decades of research, no gene therapy treatments have made it out of clinical trials. But given the difficulty of getting the immune system to buckle down and make antibodies against HIV on its own, using gene therapy starts to make a kind of sense. (more…)

An image analyzed by the researchers, before retouching, after retouching, with an overlay that shows the strongest retouching in red, and with two facial overlays showing other measures of retouching.

What’s the News: It’s not news that in the age of Photoshop, celebrities and models in magazines have started to look like perfect aliens crash-landed among we ugly Earthlings. But though sometimes it’s obvious when a photo editor has gone too far (witness the Ralph Lauren her-head’s-bigger-than-her-pelvis debacle), the gap between what real people look like and what magazines and other media regularly show has grown distressingly wide without most people consciously noticing it, creating a sea of misinformation that may contribute to body-image disorders.

An analytical tool developed by Dartmouth scientists, though, picks up and quantifies those alterations, potentially providing a useful metric for policymakers looking to set boundaries on how much limb-stretching, torso-trimming, face-smoothing alteration is appropriate.

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A Gallup poll reports that on average Americans weigh almost 20 pounds more than they did in 1990, based on the self-reports of more than 1,000 people. The average man weighs 196 pounds while the  average woman is 160 pounds. And most of us—62 percent—are already overweight or obese.

But that doesn’t mean we’re ready to come right out and admit it, at least not to a telephone pollster. When asked how they would describe their own weight, only 39 percent of Americans described themselves as “overweight,” while 56 percent reported their weight was “about right.” Neither of these metrics have changed very much since the poll was first given 21 years ago.

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When it comes to acetaminophen (aka Tylenol or paracetamol), taking slightly too much for a few days may be more deadly than taking way too much all at once. A study in the British Journal of Clinical Pharmacology found that a quarter of the 663 patients admitted to the Scottish Liver Transplant Unit since 1992 suffered liver failure after a “staggered overdose,” in which people took a couple extra doses of acetaminophen for several days. 37 percent of patients with staggered overdoses died or required a liver transplant, compared to 28 percent of those with single overdoses.

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Bionic contact lenses—which would display navigation data, personal emails, or any other sort of info superimposed on the world before your eyes—have long been mainstays of science fiction. Over the past several years, researchers have been working to make the tech real-world ready, striving to find solutions to the energy, size, safety, and image-quality problems that come up when you’re trying to fit a tiny integrated circuit into something transparent that sits on an eyeball.

Now, University of Washington researchers and their Finnish colleagues have made the first functioning bionic lens: a prototype with a single LED pixel, which could be safely worn by rabbits in the lab. (The image at right shows a rabbit wearing an earlier version of the lens, which contained a circuit but no light-emitting components.) Radio frequency energy emitted from a nearby transmitter and picked up by a circular antenna a fifth of an inch in diameter, printed on the lens, powered the electronics. The transmitter supplied adequate energy from three feet away when the lens was sitting in a dish, but had to be less than an inch away when the lens was placed on a rabbit’s eye, since tissues and fluids in the body interfered with reception. Since light from such a lens would be too close for the human eye to focus, the researchers made a separate contact composed of an array of smaller, flatter lenses, which would sit on top of the bionic contact and focus the light.

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For the better part of a century, antibiotics have given doctors great powers to cure all sorts of bacterial infections. But due to bacteria’s nasty habit of evolving, along with widespread overuse of these drugs, disease-causing bacteria are evolving antibiotic resistance at an alarming rate, making it much harder, and at times impossible, to wipe them out. DARPA, the military’s research agency, is eyeing an innovative solution to the problem: Rather than struggling to make better antibiotics, ditch them altogether. It may be time to start killing bacteria a whole new way.

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Cardiomyocytes damaged by a heart attack

What’s the News: Scientists are devoting countless research hours to treatments based on embryonic stem cells, differentiating these blank-slate cells from embryos into brain cells, light-sensing retinal cells, blood cells, and more to replace damaged or destroyed tissues in the body. Now, a new study in mice shows such that nature has arrived at just such a solution, too: When a pregnant mouse has a heart attack, her fetus donates some of its stem cells to help rebuild the damaged heart tissue.

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What’s The News: Three 16-year-old  teenage boys in Texas had heart attacks shortly after smoking a product called k2, or Spice, according to a study published this month in the journal Pediatrics. The report highlights a growing public health problem: the increased availability and use of synthetic cannabinoids, which when smoked mimic the effects of marijuana but typically can’t be detected in drug tests. While the U.S. Drug Enforcement Agency secured an emergency, one-year ban of five synthetic cannabinoids in March of this year, most of the hundreds of such chemicals remain basically legal, widely available, little understood, and potentially harmful.

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Hookworms are longer-lived than viruses and bacteria;
they could have had a more significant effect on human evolution.

Humans live in all sorts of places—high deserts, tropical lowlands, frigid tundra. Over the millennia, you’d expect each population’s assortment of genes to evolve to reflect the demands and dangers of its home environment: those who live in the deserts would possess genes for extra skin pigments to help keep their tender integument from burning (like African peoples), and those who live in sub-zero climes much of the year would have genes that keep them well-insulated in fat (like the Inuit). But what if factors other than climate, like the food available nearby or the viruses, bacteria, and parasites native to the area, also had an effect on various human populations’ genetic toolkits?

It’s a fascinating question, but, given that we have to reconstruct all this supposed evolution from the current state of modern genomes, finding an answer isn’t easy. A recent paper takes an important first step by looking for correlations between 500,000 different genetic markers and certain environmental characteristics, like humidity, temperature, the local diet, and the prevalence of parasites and other pathogens.

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For more than a decade, Geron has been a pillar of human embryonic stem cell research. They were the first to embark on embryonic stem cell trials, with a treatment for patients with spinal cord injury last year. They also have the distinction of having funded the research that isolated the first human embryonic stem cells, way back in 1998. But the company has just announced that they will be shuttering the stem cell portion of their operation.

Their spinal cord trial to assess whether a low dose of cells in a newly injured spine is safe, which had enrolled four patients, had been progressing as expected, so it’s not that they’ve lost faith in the science. It’s all about the money: Geron has two cancer drugs in clinical trials, and according to their announcement, this was the only way to continue supporting that research without having to raise more funds. They’ll be laying off 38% of their employees as a result of the decision. The four patients will continue to be monitored.

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You can dream, but…lab-grown processed meats, let alone steak, are a very
long way off still.

Part of what stands between you and a lab-grown meat patty (a perennial source of fascination around here) is your gag reflex: the pale strips of cultured muscle cells that are currently the top contender for Petri-dish burgerdom look like scraps of mold, and they must be “exercised”—stretched between Velcro tabs—to strengthen and gain meat-ish texture. A patty made from them will be a hand-assembled stack of about 3,000 scraps, and in order to give the stuff color and iron, the lead scientist of the project opined to Reuters, they might need to soak it in lab-grown blood. Gah.

Still, factory farming ain’t pretty either, and the sheer amount of land and other resources we dedicate to meat production can be enough to make you gag as well.

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