TIME Diet/Nutrition

Here’s What Happens To Your Steak When You Grill It

Nothing says the Fourth of July like juicy seared food, so here’s a quick lesson on the science behind grilling

It’s time to throw nearly everything you can think of—meat, chicken, fish, vegetables and even fruit—on the grill and give it a good sear. But what makes food cooked over a fire taste so good? Here’s the simple (we promise, it’s not that complicated) science behind what makes red meat red, when to take your food off the flame, and whether gas or charcoal is really better for that getting that smoky flavor, thanks to the experts at the American Chemical Society.

TIME Obesity

Injecting This Drug Helps Patients Lose Weight

Daily shots of liraglutide (Saxenda), recently approved by the FDA, helps overweight or obese patients lose weight

In a study published in the New England Journal of Medicine, researchers say that the only injectable weight loss drug approved by the Food and Drug Administration (FDA) helps people to lose more than 12 pounds, more than twice as much as people taking a placebo.

The study is one of several that the FDA considered before approving the drug in 2014. It included data on 3,731 patients who were randomly assigned to take liraglutide or a placebo for just over a year. The trial continued to follow the patients for another year, and that data will be published soon.

MORE: This Pill Can Trick the Body Into Losing Weight, Study Finds

Liraglutide is similar to an already approved drug to treat type 2 diabetes, but is used in higher doses for weight loss. The drug mimics the effects of a hormone that works in the gut to signal the brain that you’ve eaten enough and feel full. As a diabetes drug, it helps the beta cells in the pancreas release insulin to keep blood sugar levels in check. In the NEJM study, none of the patients had diabetes, although some were pre-diabetic, and the FDA says liraglutide for weight loss should not be used together with the diabetes drug, also made by Novo Nordisk.

According to the study’s lead author, Dr. Xavier Pi-Sunyer, director of the obesity research center at Columbia University, liraglutide works as well as phentermine-topiramate (Qsymia), which doctors believe works by suppressing appetite. They key to making any weight loss medication effective, he says, is combining it with diet and exercise changes as well, which is what the participants in the study did. One advantage of liraglutide is that it can be used by women in their child-bearing years.

So far, the side effects of litaglutide, which include nausea, diarrhea, gall bladder abnormalities and pancreatitis, were minimal and did not outweigh the benefits of weight loss. But in approving the drug, the FDA asked the company to continue to study the drug to ensure that the adverse events remain within an acceptable range.

TIME medicine

How This Common Drug Can Have Lasting Effects on Kids

Antibiotics are prescribed for a range of childhood ailments, from ear to throat infections. But the drugs may be changing kids’ health in potentially unwelcome ways

In a study published in Nature Communications, scientists document the possible long-term effects of antibiotics when they’re used early in life. Their study involved mice, but the team used the drugs in doses and treatment regimens that mimic those frequently administered in young children.

Dr. Martin Blaser, professor of medicine and microbiology at New York University Langone Medical Center, and his colleagues tested three different antibiotic regimens: one involving amoxicillin, another involving macrolides and a final one that combined the two. They compared these animals to mice that received a placebo. The mice got antibiotics 10 to 15 days after birth, then again 27 days later and finally after day 39. They lived for 160 days, at which point they were sacrificed and their gut bacteria were studied.

MORE: Here’s What Eating Nothing But McDonalds for 10 Days Does to Your Gut Bacteria

Compared to the mice taking the placebo, the antibiotic-treated animals had less diverse communities of bacteria, and the proportions of the bugs living in their guts were also different. The macrolides seemed to have the biggest effect on reducing microbial richness, while amoxicillin led to abnormally large bones. The changes in the microbiome persisted even to the animals’ death, nearly four months after their last antibiotic dose.

“There are really long-term, probably permanent effects on the microbiome from antibiotics,” says Blaser. “We showed changes in the richness and the community structure, and also the genes present in the bacteria.”

MORE: Antibiotics Before Age 2 Increase Risk of Childhood Obesity

What this means for humans still isn’t clear from this study, but the findings do provide hints. Other studies that have analyzed the potential effects of antibiotics found that children receiving more rounds of the drugs because of early infections tend to be heavier and are more likely to be obese as adolescents and adults. And the earlier children are exposed to the drugs, the more likely their metabolism is to be affected.

Blaser notes that antibiotics are a necessary and potentially life-saving treatment for some, but for many infections, their risks might be greater than their benefits. “If what we found in mice is true for human children, then this is yet another reason to be cautious in using antibiotics,” he says. “We know there are kids who are severely ill who must have antibiotics. But there is a larger number of kids who are only mildly ill. The question is, what proportion of them really need antibiotics?” Based on the animal data, he says, the first two to three years of life are particularly important for development, and doctors and parents should be judicious about prescribing antibiotics during this sensitive time.

TIME Diet/Nutrition

New York City Restaurants Are Cleaner Than Ever

18% fewer eateries have been cited for evidence of mice

It’s been five years since New York City instituted a strict grading policy assessing restaurants for cleanliness, food safety and handling—an attempt to address its somewhat unsavory reputation as a mecca for unsanitary eating establishments.

Now, in the latest report, city health officials have some good news: 95% of restaurants now earn A grades, and violations that can contribute to foodborne illnesses have dropped by 11%, giving New York its cleanest report card since the program began.

The requirements and methods of the health inspections are not without critics; even high-end establishments with Michelin-star honored chefs like Per Se were notoriously cited for not maintaining hot foods at high enough temperatures or cold foods at cold enough temperatures, despite commonly used practices of “resting” dishes after they come out of the oven or refrigerator to balance flavor and temperature. But the system works, say health officials. The report says that 37% more new restaurants in the city earn A grades in their first year compared to five years ago, and 18% fewer eateries have been cited for evidence of mice.

The program allows eating establishments one do-over; if they don’t meet criteria for earning an A grade, they have up to 30 days to fix their violations and receive a second inspection before getting the final grade that gets posted on their window. That posting, says Dan Kass, deputy commissioner for environmental health at the New York City Department of Health and Mental Hygiene, is key to the program’s success. “You need transparency in governmental inspection programs,” he says. “It’s the best way to inform the public and encourage them to vote with their feet and the best way to motivate restaurants—especially those that lag behind others in hygiene and food safety practices—to feel motivated to comply [with health regulations.]”

When the letter grading and public posting of the grades began five years ago, says Kass, officials expected about a 5% improvement in grades every year. “We have seen much more rapid change than that,” he says, “and it truly influences the practice of food safety in restaurants.”

The department now plans to launch a food safety workshop for restaurant workers—not just owners—to help them better understand the value and importance of proper handling and storing of food. But the public and prominent posting of letter grades will remain, so diners will still have a quick and easy way of knowing where the restaurant stands with respect to food safety and sanitation. “Inspections and education alone are insufficient to drive restaurants to improve,” Kass says. “Threats of fines may help, but those too are insufficient to move some restaurants to really change practices and put the public’s health first. There is no question that public transparency and making the information available to public at the point of sale is probably the most important driver—at least for the improvements we see.”

In fact, the system is gaining in popularity; Yelp reviews now include the grades or number scores for restaurants in cities that provide them.

TIME Brain

Alzheimer’s May Begin 20 Years Before Symptoms Appear

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PASIEKA—Getty Images/Science Photo Library RM

The two decade mark is the earliest that scientists have placed the beginnings of the disease. The good news is that gives doctors a long window of time in which to slow down or reverse the condition

The latest breakthroughs in Alzheimer’s research focus on the time well before patients even know they might have the neurodegenerative condition. Studies so far have found evidence that the biological processes that cause the mental decline may begin 10 to 12 years before people first notice signs of cognitive decline. But in the most recent report published Wednesday in the journal Neurology, experts say that the disease may actually begin even earlier — 18 years earlier, in fact — than they expected.

MORE: Mental and Social Activity Delays the Symptoms of Alzheimer’s

For 18 years, Kumar Rajan, associate professor of internal medicine at Rush University Medical Center, and his colleagues followed 2,125 elderly people with an average age of 73 and who did not dementia. Every three years, the researchers gave the volunteers mental skills tests, and then compared these results over time.

When the looked at the group that went on to receive an Alzheimer’s diagnosis, they found that these people showed lower scores on their tests throughout the study period. In fact, their scores steadily declined with each test. For each unit that the scores dropped on the cognitive tests, the risk of future Alzheimer’s increased by 85%.

MORE: Many Doctors Don’t Tell Patients They Have Alzheimer’s

Rajan stresses that the results only link cognitive testing scores on broad, group-level risk, and can’t be used to predict an individual’s risk of developing the disease. For one, more research will be needed to find the range of decline that signals potential Alzheimer’s dementia. But the findings do set the stage for studying whether such a non-invasive, easily administered test can, or should be, part of a regular assessment of people’s risk beginning in middle-age.

That way, he says, people may have a longer time period in which to hopefully intervene to slow down the disease process. Rajan plans to study whether brain-stimulating activities like crossword puzzles or learning a new language and social interactions can improve the test scores, and in turn slow the time to diagnosis of Alzheimer’s. At the very least, he says, the current data shows that there is a longer window of time in which people might be able to intervene in these ways and potentially delay Alzheimer’s most debilitating effects.

TIME medicine

Here’s What Science Says About Medical Marijuana

It’s buyer-beware for medical marijuana users, since the data supporting the benefits of cannabinoids are still in flux, and most marijuana edibles aren’t well labeled

There’s a big difference between anecdotal evidence and scientific proof, and the field of medical marijuana research is filled with more of the former than the latter—in part because marijuana is notoriously difficult to study because it’s classified as a schedule-1 drug.

Scientists led by Penny Whiting from University Hospitals Bristol in the U.K. report in JAMA that there is only moderate-quality evidence supporting the benefits of medical marijuana, and only for certain conditions. The majority of studies involving medical marijuana are of lesser quality and therefore more likely to be biased and provide unreliable results.

MORE: Teens Don’t Smoke More Pot After Medical Marijuana Laws Passed, Study Finds

In all, Whiting and her colleagues analyzed 79 randomized trials, the gold standard in medical research in which volunteers are randomly assigned to take a cannabis-related product or a placebo. The studies evaluated marijuana’s ability to relieve a range of symptoms including nausea from chemotherapy, loss of appetite among HIV positive patients, multiple sclerosis spasms, depression, anxiety, sleep disorders, psychosis and Tourette syndrome. Most of the studies showed improvements among the participants taking the cannabinoid products over those using placebo, but in many, the scientists admitted that they could not be sure that the effect wasn’t simply due to chance since the association was not statistically significant.

MORE: The Great Pot Experiment

The strongest trials supported cannabinoids’ ability to relieve chronic pain, while the least reliable evidence involved things like nausea and vomiting from chemotherapy, sleep disturbances and Tourette syndrome. Cannabinoids were, however, connected to more adverse events such as nausea, vomiting, dizziness, disorientation and hallucinations than placebo.

Summing up the state of the evidence, Whiting and her colleagues write that “Further large, robust, randomized clinical trials are needed to confirm the effects of cannabinoids, particularly on weight gain in patients with HIV-AIDS, depression, sleep disorders, anxiety disorders, psychosis, glaucoma, and Tourette syndrome.”

MORE: Even in Colorado Medical Marijuana Can Still Get You Fired

That puts patients who try medical marijuana products at a crossroads — in 23 states and Washington, DC, laws allow doctors to recommend cannabis products for their patients for medical reasons. But with little in the way of solid scientific evidence for which products works best, and in which doses, it’s up to the patients to adopt trial-and-error to figure out which, if any cannabinoids help to relieve their symptoms.

Adding to the confusion for patients, another study published in the same JAMA issue shows that medicinal marijuana food products, which include things such as candies, brownies and teas, aren’t often labeled correctly when it comes to their most active cannabis ingredient, and that the amounts are inconsistent. Ryan Vandrey, associate professor of psychiatry and behavioral sciences at Johns Hopkins University School of Medicine and his colleagues evaluated the contents of 75 products from 47 different brands purchased at marijuana dispensaries in San Francisco, Los Angeles and Seattle, where medicinal marijuana use is legal. When they analyzed them for their content of THC and cannabinoids, the two most concentrated chemicals found in marijuana, they found wildly divergent amounts from what was noted on the products’ labels. Among them, only 17% were accurately labeled, with 23% of the products containing more of these compounds than listed, and 60% containing less than advertised. The labels noted that anywhere from 2 mg to 1000 mg of these agents were in the products, while the lab-based analysis revealed readings as low as 1mg to as high as 1237 mg. “When I have a health condition, and need to go buy my medicine, I want to make sure I know what I’m getting,” says Vandrey. “I want to make sure the dose I buy is the same today and the same the next time and the same the next time I buy it. I want reliability and accuracy so I don’t end up with problems.”

MORE: How Much Does Marijuana Impact Your Driving?

But medical marijuana products, he says, aren’t regulated by the same system that vets other pharmaceutical drugs. In fact, cannabinoids are not regulated at all, since the federal government still considers marijuana an illegal substance and therefore does not acknowledge that marijuana-based therapies exist at all. So far, 23 states have legislated such medicinal marijuana into legality, which means that legislation, and not scientific criteria, have “approved” these compounds for medical use. The results? “What we saw was that there cant’ be much if any consumer confidence within the cities we purchased and tested products,” says Vandrey.

For the larger medical marijuana distributors who see the emerging market as a profitable business, there’s the concern that profit motives may push them to under-deliver the amount of THC or cannabinoid they note on the label. And for the smaller outfits, it could be a matter of not knowing how to extract and measure the active ingredients from the cannabis plant and distribute it in a consistent way in a batch of tea or baked goods.

How can consumers know what they’re getting in a medical marijuana edible? They can do their homework and talk to other consumers and the dispensary about dosing of THC and cannabinoids, says Vandrey. Or they can try to test the products themselves, which some states offer in an effort to standardize and gain more control over these products. But ultimately, he says. “if states are going to supersede federal law and say we think there is medical benefit in marijuana, and we want it to be available to our residents, then it should also be the responsibility of the states to set up appropriate programs for regulating and overseeing the quality assurance and manufacturing standards for medications being sold.”

TIME medicine

Here’s How Skinny Jeans Are Hurting Your Health

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Adrianna Williams—Getty Images

They may help you look slimmer and be the perfect partner for tees, but skinny jeans may be damaging your nerves

If we had to point to an unhealthy fashion choice, we’d probably start at our feet, with sky-high heels. But a case study shows we may need to look a little higher, at the skinny jeans that have dominated the market for years.

In the Journal of Neurology, Neurosurgery and Psychiatry, researchers from Australia describe the case of a woman who experienced nerve damage severe enough to cause numbness and hospital care after a day of wearing skinny jeans.

The 35-year-old was helping a relative move, so she spent most of the day squatting while packing. Throughout the day, she felt her jeans get increasingly tight, until, while walking home in the evening, her feet went numb and she fell. Not able to get up, she spent several hours on the ground before she was taken to the hospital.

There, her legs and ankles had become so swollen that emergency room staff had to cut her jeans off. Her ankles and toes were weak, but the rest of her legs, including her knees and hips, were working normally.

When the doctors did studies on how her leg nerves were functioning, they found blockage of the nerve that directs the lower leg and feet. In fact, they say, any compression of the area just under knee can squeeze this nerve and cause weakness, numbness or pain by damaging this nerve. In her case, the squatting probably squashed the nerves feeding into each leg, and the skinny jeans didn’t help when the swelling started, further constricting them and crushing the nerves. After four days in the hospital with IV hydration, the bloating went down and the woman could walk again on her own.

Lesson: don’t wear skinny jeans if you’re going to do a lot of squatting or bending. They might not directly pinch the nerves in your legs but they can make the condition worse — enough to numb your feet and require several days in the hospital.

TIME archeology

The Mystery of a 8,000-Year-Old Skeleton Has Been Solved

KENNEWICK MAN SKULL
Elaine Thompson—AP A plastic casting of a controversial 9,200-year-old skull sits in the basement of archaeologist James Chatter's home July 24, 1997 in Richland, Wash.

He may have lived a simple life back then, but Kennewick Man’s remains have sparked controversy and legal battles that the latest scientific investigation may finally put to rest

Finding a human skull doesn’t happen often, but the skull that two college students stumbled upon in the Columbia River in 1996 proved rarer still. It happened to belong to an ancestor that roamed North America nearly 8500 years ago. Near the skull were remains of practically an entire skeleton belonging to a male who was likely buried along the riverbank by his people in Kennewick, Washington.

Kennewick Man, as he is known, quickly became the subject of a custody battle between scientists eager to study his remains, which are among the oldest and most complete of a human ancestor in North America, and a group of five Native American tribes who claimed the bones as the Ancient One, one of their own forebears. The U.S. Army Corps of Engineers, which manages the land on which the remains were found, intended to return the ancient bones to the Native Americans. The archeologists sued for the right to study them, and in 2004, a judge ruled that the fossils should be studied further.

MORE: Ice Age Infant’s Genes Show That Native Americans First Came From Asia

The results of that analysis were published in a popular book that detailed the lifestyle that Kennewick Man likely led, but since then, advances in genetic sequencing made it possible to do a complete genome study of his DNA. And those results, published in the journal Nature, resolve a long-standing dispute over where Kennewick Man came from — Europe or Asia, or whether he was, as the Native American tribes claimed, an early ancestor who gave rise to some of the Native American populations that subsequently resided in North America.

His genes show that Kennewick Man was more closely related to Native Americans than to European or Asian populations. “It’s very clear the genome sequence shows that he is most closely related to contemporary Native Americans,” says Eske Willerslev, from the Center for GeoGenetics at the University of Copenhagen, who led the analysis.

MORE: A Tale Told by Ancient Bones

Hints of these results first leaked in January, when emails obtained from a Freedom of Information Act request by reporters at the Seattle Times revealed that Willerslev’s group shared some of their early findings with the Army Corps of Engineers to update them on the genetic analysis, which was done in Copenhagen. And presumably, it puts to rest any lingering questions about Kennewick Man’s origins.

Those began when the first archeologist to evaluate the skull’s anatomical features declared it to be more Caucasian than Native American, and continued when Douglas Owsley, a physical anthropologist at the Smithsonian Institution who is considered the expert on North American human remains, agreed with that conclusion. Owsley pointed out that the prominent forehead of Kennewick Man and thinner brain case made him more like Japanese Ainu or Polynesians rather than Native Americans.

His genes tell a different story, however, and when Willerslev’s group also compared Kennewick Man’s DNA to that of the Ainu, Polynesians and Europeans, they found that it did not share the same similarities as it did with those of the contemporary Colville, a Native American tribe from the Columbia River area that agreed to provide DNA samples. No other Native American groups provided genetic material, so it’s possible that other tribes have an even closer connection to the ancient remains than the Colville.

The results do not show that Kennewick Man was a direct ancestor of any tribe living today, says Willerslev. It’s not known whether, for example, an older population of Native Americans living in North America then split into a branch that led to Kennewick Man, and another to the contemporary tribes such as the Colville, or whether Kennewick Man is the ancestor of the Colville and other modern Native Americans.

The genetic analysis does little to change archeologists’ current theories about the first North Americans. The first people to spread into the Americas likely came 5,000 to 6,000 years before Kennewick Man’s time, probably from Siberia via a now non-existent land bridge that allowed them to traverse the Bering Strait.

As for Kennewick Man’s future, Willerslev says that he has been in contact with several members of the Colville throughout the analysis and says that “To me, they seemed pretty excited, and found it interesting.” Whether the remains will now go back to the Native American groups under the Native American Graves Protection and Repatriation Act isn’t clear. But Willerslev acknowledges the irony in the findings. “The reason why we came to this conclusion scientifically speaking is because the remains were almost kept out of science,” he says.

TIME medicine

Scientists Find a Gene That Regulates Sleep

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Vincent Besnault—Getty Images

It's a study in flies but it could have implications for us, too

Flies, it turns out, sleep about as much as young children do. Males need about 12 hours a day, while females can do with about 10 hours. To find out which genes might be responsible for guiding how much slumber flies get a night, Kyunghee Koh did a massive experiment that you can only do with fruit flies.

She and her team at Thomas Jefferson University reported in the journal Current Biology that they took 3,000 flies, introduced random mutations in them and then monitored how well they slept. That allowed them to zero in on the genes that most directly affected slumber, and they found one, taranis, that may become an important target for sleep-related research even in people.

Flies with abnormal forms of taranis only get about 25% of their daily sleep; removing the gene keeps the flies buzzing almost non stop.

Koh’s team found that taranis works with a couple of other proteins to balance sleeping and waking. Normally, taranis and cyclin A pair up to keep the activity of another enzyme down. That enzyme generally keeps the flies awake. So when all three are working in concert, taranis and cyclin A shut down the enzyme so flies can get 10 to 12 hours of sleep. But when taranis is mutated, it doesn’t do its job as well, and the enzyme keeps the flies alert and unable to sleep.

It turns out that taranis has a related gene in mammals that may work in similar ways. The gene typically controls the way cells divide, “We don’t know yet whether these genes have a role in sleep in mammals or humans, but our hope is that somehow these genes we find in flies may have similar roles in people, and might ultimately give us some novel drug targets to help us sleep better,” says Koh.

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