TIME medicine

Newer Birth Control Pills Raise the Risk of Blood Clots

A new study puts a number on the risk of developing potentially fatal blood clots after using the pill

Blood clots have been a known risk of oral contraceptives since the 1990s, but for most women, the chances seemed small enough to justify taking the Pill. Now, in a report published in The BMJ, scientists led by Yana Vinogradova, a research fellow at the University of Nottingham, found that using the Pill was linked to anywhere from a two- to more than four-fold increased risk of developing clots compared to women who didn’t take oral contraceptives.

“Our study suggests that the newer contraceptives have a higher risk of [blood clots] than the older agents,” Vinogradova tells TIME in an email. Overall, the risk for women on the Pill was nearly three times that of women not taking the medication. The risk was highest for people taking Pills that contain newer types of the progestogen hormone, such as drospirenone, desogestrel, gestodene, and cyproterone, as compared to people taking the Pill with first-generation versions of the hormone (levonorgestrel and norethisterone).

The difference essentially boils down to the progesterone part of the drug; since the original pill was introduced in 1960, drug developers have tweaked the progesterone to lower side effects such as acne, headache, weight gain and breakthrough bleeding. But the price for those modifications may be more blood clots.

Even after Vinogradova and her team adjusted for the potential contributions of things like cancer, heart disease, varicose veins, arthritis, smoking and obesity on the risk of blood clots, the link between the newer contraceptives and increased risk remained strong.

“While [blood clots] are a relatively rare problem, they are serious and potentially avoidable with the appropriate drug choice,” says Vinogradova. “Doctors need to consider all health issues when prescribing contraceptives, selecting a drug type associated with the lowest risk for patients with particular susceptibilities.”

Whether that means that doctors should start with prescribing the older formulations first—as well non-hormonal birth control like the copper IUD—isn’t clear yet, since the newer forms have certain advantages, including the fact that they disturb the cholesterol system less, which may be important for diabetic women.

The blood clot risk, however, is something that doctors should consider when prescribing the Pill. And since there are different formulations available, Vinogradova says doctors should monitor their patients for any potential symptoms of poor circulation and switch to other formulations if needed.

TIME Cancer

How a Common Childhood Vaccine Helps Ward Off Cancer

It reduces the risk of childhood leukemia by 20%

Scientists now understand why a common childhood vaccine reduces the risk of leukemia.

Researchers previously knew that the vaccine against Haemophilus influenza type B, or HiB, reduces the risk of acute lymphoblastic leukemia, the most common form of childhood cancer. But now a new study published in Nature Immunology explains why this is the case.

Dr. Markus Müschen and his team on the study used a mouse model and found that recurring HiB infections, which can happen easily in children who have not been vaccinated, can cause certain enzymes to activate and push common precancerous blood cells into cancer. So, vaccines against HiB infections also protect children from this path to leukemia.

Müschen told the New York Times that the HiB vaccine, which is routinely given to children, has led to a 20% reduction in the risk for leukemia.


TIME medicine

Tylenol During Pregnancy Could Harm Male Babies, Study Shows

It reduces testosterone production in the womb

Taking too much Tylenol during pregnancy could reduce testosterone levels in male babies, according to a new study.

The study, published in Science Translational Medicine, found that prolonged use of acetaminophen, the drug in Tylenol, by a pregnant mother reduced production of testosterone in her unborn son.

The study used mice that carried grafts of human tissue. After one day of exposure to the drug there was no effect on testosterone production, but after seven days the amount of testosterone was down by 45 percent.

Limited testosterone in the womb is related to increased risk of infertility, testicular cancer and undescended testicles.

“We would advise that pregnant women should follow current guidance that the painkiller be taken at the lowest effective dose for the shortest possible time,” said Rod Mitchell, one of the authors of the study from the University of Edinburgh.

Acetaminophen drugs like Tylenol or Panadol are the most common medicine for managing pain or fevers during pregnancy.

TIME medicine

The Science of Bouncing Back

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Scientists now know why some people rebound so well from setbacks. They also know how the rest of us can be more like them

Dr. Dennis Charney knows that each of his five children has hated him at some point or another–particularly when he dragged them along on one of his “semidangerous” adventure trips. He recalls a perilous hike with one of his daughters, who was 13 at the time. “Some weather came in, and there was some wildlife. When she said she despised me it came, like, from her soul,” says Charney, 64, who is now dean of the Icahn School of Medicine at Mount Sinai in New York City.

His son Alex knows the feeling. A decade ago, Charney took him on a kayaking trip to Patagonia with his best friend, Dr. Steven Southwick. It rained the entire time, the life jackets didn’t fit, and Alex had to share a broken-ruddered boat with his dad for 12-mile runs every day. When it was all over, Alex informed his father he never wanted to speak to him again.

But as a psychiatrist who, with Southwick, has studied the science of resilience for two decades, Charney knows there are benefits to forcing people out of their comfort zone. Resilience is essentially a set of skills–as opposed to a disposition or personality type–that make it possible for people not only to get through hard times but to thrive during and after them. Just as rubber rebounds after being squeezed or squished, so do resilient people.

It’s a tantalizing arena for neuroscientists, who are getting better at understanding why some people bounce back from difficult experiences–both those they seek out and those that blindside them–while others don’t fare quite so well. And thanks to modern imaging, scientists can peer inside the brain in real time to see how, and to what extent, stressful situations change the structure and functions of the brain. They are also learning that training for resilience can change the brain to, well, make it more resilient.

Much of the new evidence suggests that with a little practice, anyone can develop resilience, says Southwick, 67, a professor of psychiatry at the Yale School of Medicine. There are lots of ways to intervene so that stress or trauma doesn’t derail you, he says. No one size fits all.

That’s good news, because humans get stressed far more than they realize. The hot-and-cold boss, the traffic delays, the spat with their spouse, the monthly bills–these are all registered as stress in the brain. “The vast majority of us will be faced with one or more major traumatic stressors during a lifetime,” says Southwick. But the countless smaller stresses also take a toll. Resilience, research shows, can help with that, and it’s not a moment too soon, given that nearly all our modern ills, including heart disease and possibly even brain disorders like Alzheimer’s disease, have stress as a common risk factor.

With heart disease killing far more Americans than anything else and rates of Alzheimer’s expected to double in the coming decades, scientists are hard at work to find promising ways to prepare a large, aging population for healthier ways of dealing with stress. “Resilience training can help people deal effectively with chronic disease and improve their quality of life,” says Charney. “It helps people cope.”

Forget the old adage that you won’t know what you’re made of until you’re tested; the latest science shows that if you train your brain, how you act under pressure can, in large part, be up to you.

Understanding Resilience

Studying the capacity to successfully adapt to challenges wasn’t on researchers’ radar before World War II. Ann Masten, a resilience researcher and professor of child development at the University of Minnesota, notes that the war produced no shortage of traumatized and displaced people–many of them children who were orphaned, injured or sick, which is precisely the kind of thing that puts people at risk for trouble later on. But psychologists caring for these children noticed that some fared improbably well, despite their circumstances.

Researchers wondered why, and by the 1950s, Emmy E. Werner, a developmental psychologist and pioneer in resilience research, was inching toward an answer. In 1955 she and a team from the University of California, Berkeley, began what’s considered the most important longitudinal study in the field: a 40-year project following nearly 700 children in Kauai, Hawaii, many of whom had alcoholic parents. Her research showed that a third of the most vulnerable children adapted exceedingly well over time. Werner wanted to know what makes a person thrive in the aftermath of adversity. The study found that factors like having a tight-knit community, a stable role model and a strong belief in their ability to solve problems helped children succeed.

“As soon as people began to pay more attention to positive outcomes and positive development, they realized there were a lot of children doing well,” Masten says.

Most resilience research is still done on survivors of catastrophes–floods, fires, tsunamis, drought–as well as on soldiers. But while it’s tempting to think of resilience as a skill people won’t need until they’re locked in a cell or their home is sucked into a tornado, resilience experts say those extremes are a kind of psychological exaggeration of the things the rest of us go through.

After interviewing scores of Vietnam prisoners of war, Army Special Forces and survivors of horrific tragedies, Charney and Southwick became convinced that anyone could train him- or herself to be more resilient. POWs told Southwick and Charney that with only two resources–free time and their minds–they were able to do remarkable things they couldn’t do before; one developed a knack for multiplying huge numbers in his head, while another built a house in his imagination (and then later, on solid ground). “It said to us that there’s enormous untapped capacity of the human brain,” Charney says.

Discovering why some of us fare better than others has always been at the heart of resilience research. Now techniques like functional magnetic resonance imaging make it possible for scientists to look beyond their own observations of people and into the parts of their brains that govern emotion. By observing patterns of blood flow, they can measure brain activity and see, for instance, what stress looks like in different people–which is useful because how we respond to stress is a critical part of resilience. Like the animal whose pulse returns quickly to normal once it has successfully outrun a predator, resilient brains seem to shut off the stress response and return to baseline quickly. “Resilient people seem to have the capacity to appropriately regulate the subcortical fear circuits under conditions of stress,” says Charney.

It doesn’t take a predator to trigger a stress response in modern humans. Some research shows that even feelings of social pain–like rejection and loneliness–zoom along the same neural pathways as fear. “This notion that I’m going to be rejected or fail or won’t be accepted by the group activates the same circuits as if I saw a wolf,” Southwick says. It’s an evolutionary hanger-on from when our ancestors survived only in groups.

The problem is, even though we’re no longer bumping into wolves, we’re constantly activating the same neural pathways of fear with everyday stressors–worrying about the future, fretting about the past. The more we use this neuronal superhighway, the more efficient it grows, and this mode of thinking becomes our default. But new research shows humans can train their brains to build and strengthen different connections that don’t reinforce the fear circuit. Over time, if people use this new pathway enough, it can become the new response to stress.

Richard Davidson, a neuroscientist at the University of Wisconsin, Madison, thinks he’s found a connection in the brain that is especially important for resilience: the path from the prefrontal cortex–the seat of cognition and planning–to the amygdala, an emotional part of the brain that responds to threats. A stronger connection means the prefrontal cortex can more quickly tell the emotional amygdala to quiet down, Davidson writes in his book The Emotional Life of Your Brain.

Scientists can see how resilient brains respond to emotion differently, found Martin Paulus, scientific director and president of the Laureate Institute for Brain Research in Tulsa, Okla. In a series of brain-imaging experiments on resilient Navy SEALs, Paulus showed the SEALs a color cue that signaled they were about to see an emotional picture. Paulus saw that their brains anticipated the emotion more quickly than the average brain, letting them jump nimbly between different types of emotions. Paulus says that in his research he has seen differences in the brains of people with anxiety or depression that suggest they have a hard time letting go of emotions and are often too engaged in emotional processes. The Navy SEALs, on the other hand, weren’t glued to the emotional experiences. Why? “They’re more resilient,” he says. And just like working your biceps or your abs, say experts, training your brain can build up strength in the right places–and at the right times–too.

The Workout for Your Brain

A good way to gauge how close you are to resilience is to consider how you react when things don’t go your way, Davidson says. His research shows that the way we cope with little stressors strongly predicts how we’ll do once the big stuff hits. Personality is not as big a factor as one might think: Pollyannas are not always more resilient than pessimists, and even stubborn curmudgeons can pick up traits associated with resilience.

What’s more, scientists have identified at least a dozen ways that people can up their resilience game, which Charney and Southwick detail in their 2012 book, Resilience: The Science of Mastering Life’s Greatest Challenges, to be updated this year with reams of new research on the topic. “For resilience, there’s not one prescription that works,” Charney says. “You have to find what works for you.”

So far, researchers have found that facing the things that scare you relaxes the fear circuitry, making that a good first step in building resilience. They have also found that developing an ethical code to guide daily decisions can help. Studies have shown that traits scientists once thought of as nice but unnecessary–like having a strong network of social support–are critical to resilience. “Very few highly resilient individuals are strong in and by themselves,” Southwick says. “You need support.” There are even neurobiological elements to social support. When people are exposed to a stressor in a lab, their heart rate and blood pressure don’t go up quite as much if a friend is in the room as they do if they’re alone.

In an interesting twist, scientists have learned that working the body’s muscles makes people’s minds more resilient as well. That’s because exercise also spurs the development of new neurons, which are quite literally damaged by stress, Southwick says. Over time, regular exercise can tamp down a person’s stress response.

The most compelling new research about resilience focuses on mindfulness–an area in which most people would do well to improve, since people spend 47% of their days thinking about things other than what they’re actually doing, a 2010 Harvard study found.

In a study published last year, Paulus and researchers at the University of California, San Diego, trained four Marine infantry platoons in an eight-week mindfulness course, and four platoons trained as usual. The Marines then spent a day at the Infantry Immersion Trainer facility, an elaborate mock Iraqi village the Marines use to prepare for deployment, where they were ambushed and otherwise stressed. A subset of both groups had their brains scanned before and after the intervention. When the experiment was over, researchers found that the Marines who trained in mindfulness returned to baseline levels of heart rate and breathing rate faster than those who hadn’t been trained.

They also showed lower activation in the region of the brain associated with emotional reactions. By the end of training, their brains actually looked more resilient, Paulus says. “We were able to show, at least in the brain, that we can train people to modify their brain processes toward the direction of resilience.”

Even though the Marines’ brains changed to reflect those of more resilient people, they didn’t report feeling more resilient. So researchers did another experiment, using Olympic BMX athletes. This time, they told them how their mindfulness course could be affecting their brains. “That’s particularly helpful for people who may initially not be as susceptible to mindfulness,” says Paulus, who led the research. “They may say, ‘Well, this may not be for me.’ But when we showed them that we can actually change their brains, it becomes much more interesting to them.”

Like the mindful Marines, the mindful BMX cyclers showed less emotional reactivity to a stressful task than they had before they took the course. Unlike the Marines, however, they also said they felt more resilient–likely because they had been primed to associate the exercise with that benefit. Shortly after the study ended, the athletes competed in a major BMX competition and swept the gold, silver and bronze medals. (Two years before, at the London Olympics, they hadn’t placed.) There’s no control group in real life, of course, and they might have done just as well without the training. “But they at least told us that it was particularly noticeable to them,” Paulus says.

The Meditation Miracle?

It might seem too touchy-feely to believe that becoming tougher has everything to do with tuning into the mind, the body and the present moment. But that’s precisely what Davidson from the University of Wisconsin is finding. In 1992 he wrote a letter to the Dalai Lama asking if he could study Tibetan Buddhist monks to see how meditation changes the structure or function of their brains. To his surprise, the Dalai Lama wrote back with a request that Davidson devote as much time to studying the effects of kindness and compassion on the brain as depression, anxiety and fear.

Since then, Davidson has used brain imaging to watch the brains of all kinds of people while they’re in meditation states, from novices to Buddhist monks. He’s found that consistent practice changes how the brain looks as well as how it operates. The more experienced the meditator, the more quickly the brain recovers from stress. Another recent study shows that meditation can even help decrease expression of pro-inflammatory genes.

“The changes we see aren’t just changes during the meditation state itself, but they’re changes that persist beyond the meditation state,” Davidson says. “They transform our baseline.” And a solid baseline state is what we really need when the waters get rough, he says.

That’s why Charney and Southwick emphasize again and again the importance of finding resilience-building skills you’ll stick with. When Charney lost his granddaughter and Southwick’s mother died, each leaned on the other to get through it–a case of resilience-building social support in action.

And while you won’t find Charney joining Southwick in meditation, and you won’t spot Southwick bench-pressing next to Charney in the med students’ gym at Mount Sinai, you’ll almost certainly find them building resilience together and apart. Because as they’ve learned, this stuff really pays off when you need it.

This appears in the June 01, 2015 issue of TIME.
TIME public health

80% of Sunscreens Don’t Really Work or Have ‘Worrisome’ Ingredients: Report

Here's how to find one that works

Summer is around the corner, and when it comes to sunscreen, it’s important to know how to stay covered.

Yet new research published in the Journal of the American Academy of Dermatology shows that many Americans aren’t protecting their skin as much as they should. Researchers from the Centers for Disease Control and Prevention (CDC) asked people how often they use sunscreen when out in the sun for over an hour and only 14% of men said they regularly slathered on sunscreen. Women, at 30%, were twice as diligent about putting on sunscreen—while men were more likely than women to report never using sunscreen.

The problem isn’t only compliance. The Environmental Working Group (EWG) released its 2015 sunscreen guide on Tuesday, which reviewed more than 1,700 SPF products like sunscreens, lip balms and moisturizers. The researchers discovered that 80% of the products offer “inferior sun protection or contain worrisome ingredients like oxybenzone and vitamin A,” they say. Oxybenzone is a chemical that can disrupt the hormone system, and some evidence suggests—though not definitively—that adding vitamin A to the skin could heighten sun sensitivity.

The report points to Neutrogena as the brand most at fault for promising sun protection without delivering. The EWG says that Neutrogena claims its baby sunscreens provide “special protection from the sun and irritating chemicals” and is labeled “hypoallergenic,” but it contains a preservative called methylisothiazolinone that has been deemed unsafe for use in leave-on products by the European Commission’s Scientific Committee on Consumer Safety. The company also boasts of high SPF levels like SPF 70 or SPF 100+, even though the U.S. Food and Drug Administration (FDA) says there’s only notable protection up to SPF 50, the report adds. Neutrogena did not respond to requests for comment by publication time.

In the new report, EWG also provides a Hall of Shame of products that don’t deliver on their sun protection promises, as well as a database for users to search how protective their particular sun products are—and find one that works.

To stay protected this summer, the researchers suggest, use sunscreens with broad spectrum SPF of 15 or higher, limit time in the sun, wear clothing to cover exposed skin and re-slather your sunscreen every couple hours.

TIME medicine

Rare Identical Triplets, 2 Conjoined, Born in Texas

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Corpus Christi Medical Center

The parents called the girls a miracle sent from God

A rare set of identical female triplets—including two conjoined at the pelvis— have been born at a south Texas hospital.

Corpus Christi Medical Center said the three baby girls—Catalina, Ximena and Scarlett—were delivered Saturday by C-Section one day shy of 34 weeks. All weighed 4 pounds, 11 ounces and were currently breathing without the assistance of a respirator, the hospital said.

Parents Sylvia Hernandez and Roel Torrez called the girls a miracle sent from God.

“God chose us to take care of these babies,” Torrez said in a statement released by the hospital. “We put our faith in God’s hands first and everything will be alright…”

Read the rest of the story from our partners at NBC News

TIME medicine

How Human Bones Have Changed—For the Worse

A new study investigates why modern humans have lighter bones than our ancestors

We’re definitely heavier than we’ve ever been — about two-thirds of adults are now overweight or obese — but our bones aren’t as strong as those of our forebears. In fact, they’re not even as strong as the bones of our closest living relatives, the chimps.

What caused this thinning of modern man’s skeleton? We could blame our shift from hunter-gatherer lifestyles to a more sedentary way of life, and the ensuing change in our diet. Or we could place the blame on modernization, pointing the finger at buggies, cars, planes, trains and other technological advances for keeping us off our feet and less mobile.

MORE: Milk Might Not Save Your Bones, Study Says

A report in the Proceedings of the National Academy of Sciences may provide some answers. Researchers led by Christopher Ruff, professor in the center for functional anatomy and evolution at the Johns Hopkins University School of Medicine, and his colleagues decided to find out which force was responsible for driving the lightening of our bones. Using bone samples from 1,842 people collected from all over Europe from the Paleolithic period (11,000 to 33,000 years ago) to the 20th century, they found that the biggest shift in bone strength came with the move from a hunter-gatherer way of living to an agricultural one. The move to more settled and permanent living arrangements had a dramatic effect on changes in the human skeleton. Since that time, the bones of Homo sapiens have remained relatively similar.

Ruff’s team looked at the long bones in the legs and arms, and used arm strength as a control. Any changes in mobility would be more likely reflected in the leg bones, specifically in their front-to-back bending strength. These are the parts of the legs that would show the most adaptation to walking, running and any forces provided by movement. During the Mesolithic era, 10,000 years ago, homo sapiens gradually began settling in villages and adopting a more sedentary lifestyle, and leg bones reflect this change with a decline in strength. The side-to-side strength of the leg bones changed little in this time. Arm bones also didn’t change much in strength, suggesting that it wasn’t something like diet driving the decline, but the lack of mobility that was likely responsible for the lightening of the bones.

This drop in bone strength in the lower limbs remained constant throughout the Iron Age and the Roman era, he says, and into the 20th century. That implies that urbanization, and the domestication of horses for transport and the invention of the car had little effect on the bone strength of modern man — certainly not as much as the shift to an agricultural way of life. “It was really becoming settled and living in villages and towns and agriculture that really had the primary effect on bones,” says Cullum.

That doesn’t mean, however, that our bones can’t regain some semblance of their former robustness. Bone strength is dependent on use, and that’s evidence in tennis players and baseball pitchers, who show dramatically stronger bones in their swinging or pitching arms. “Bone still have the ability to respond to more force on them,” says Cullum. “It’s not like there has been some genetic change that we can’t do anything about that has lightened the bones.” But it does take consistent and weight-bearing exercise to spur bone strength — which might be worth the effort if it helps us avoid fractures and osteoporosis.

TIME Brain

Concussions Continue to Plague Retired NFL Players

A study shows that a concussion during their playing years may have lasting effects on NFL players’ memory years later

While there may be more questions than answers about how best to protect football players from the effects of concussions, there’s more data suggesting that the negative effects of head injuries can be long lasting.

In the latest report, one of the first to combine both anatomical screening of the brain with performance on standard memory and cognitive tests, researchers found that retired NFL players who suffered a concussion may continue to experience cognitive deficits many years later.

Munro Cullum, a professor of psychiatry and neurology at University of Texas Southwestern Medical Center, and his colleagues report in JAMA Neurology that having a concussion, and in particular losing consciousness after a concussion, can have long-lasting effects on the brain. The team studied 28 former NFL players, all of whom had a history of concussion, who were compared to 21 matched volunteers who did not have a history of concussion. Eight of the retired players were diagnosed with mild cognitive impairment (MCI), which meant they had some deficits in memory but weren’t prevented from living their daily lives by these changes, and they were compared to six participants with MCI who did not have a history of concussion.

MORE: How Concussions Can Lead to Poor Grades

Overall, the retired players performed worse on average on standard tests of memory than health controls, suggesting that their history of concussion affected their memory skills in some way. This was supported by imaging data of the hippocampus, the region in the brain responsible for coordinating memory. On average, the athletes showed smaller hippocampal volumes than the controls. (The scientists did not, however, collect data on the player’s hippocampal volume before the concussion, although the comparison to the non-athletes suggests that the concussions may have influenced shrinkage in this region.) The volumes of retired players who were knocked unconscious after a concussion were even smaller than those of healthy controls, and the same was true for the athletes with MCI when compared to non-athletes with MCI.

“We know that normal aging itself is associated with some declines in both hippocampal volume as well as memory function,” says Cullum, “but it seems that those declines are accentuated when there is a concussion, and when there is a concussion with loss of consciousness.”

MORE: Judge OKs 65-Year Deal Over NFL Concussions That Could Cost $1B

The findings don’t address another big question in the field, which is how best to treat people who have had a concussion. The data is conflicting on how much rest following a head injury is ideal; most experts recommend a day or two and then gradual return to normal activities, with a break if symptoms like headaches and dizziness return.

While Cullum says that most patients with concussions recover completely within weeks of the injury, football players may be at increased risk of longer lasting cognitive deficits because of their repeated exposure to the danger. And that risk increases if they lose consciousness following a concussion. Documenting concussions and any blacking out afterward is critical for helping future physicians to manage the care of someone with such head injuries, he says.

TIME medicine

Many Probiotics Contain Traces of Gluten, Study Says

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Elizabeth Renstrom for TIME

55% of the samples tested had gluten—sometimes even when labeled gluten-free

A new study reveals that many popular probiotics contain traces of gluten, which is worrying for people who may have allergies.

Researchers at the Celiac Disease Center at Columbia University Medical Center analyzed 22 popular, high-selling probiotics and found that more than half of them (55%) contained gluten, according to research that will be presented on May 16 at Digestive and Disease Week in Washington DC.

“We see a lot of patients [with celiac] and we have a lot of patients who have it and don’t feel better,” says Dr. Peter Green, professor of medicine and director of the Celiac Disease Center. “We found previously that about 25% of celiac patients use supplements or non-traditional medical products, and probiotics were the largest and most frequently consumed. Those people [who used probiotics] had more symptoms compared to people who weren’t taking these supplements.”

Green says that data and the recent news revealing many supplements do not contain what they list on their labels prompted his team to look into the ingredients of probiotics. Using a detection technique called liquid chromatography-mass spectrometry, the researchers measured the quantity of gluten in the probiotics.

In general, for a product to be labeled “gluten-free,” the study authors note that gluten needs to be less than 20 parts per million. Their data show that most of the probiotics that contained gluten had less than that, but four brands contained more than the threshold. More than half of the probiotic brands tested by the researchers claimed to be gluten-free on their label.

Green says it’s unclear whether trace levels of gluten could be harmful for someone with celiac disease. “It hasn’t been very well studied how much gluten will cause symptoms,” he says. “But why is there any gluten in these products, and why aren’t these better regulated? People have great faith in natural products, and that’s why a lot of people eat probiotics. They should be studied and they should be regulated.”

If you have celiac disease, approach probiotics with caution, Green says. In addition to possible gluten contamination, we still don’t definitively know the benefits or harms of taking probiotics, he says. “Probiotics may turn out to be beneficial to individuals with different conditions, but to my mind, that has not be shown,” he says—and for someone with a gluten allergy, a probiotic with the ingredient could potentially be harmful.

TIME Research

The New Science of How to Quit Smoking

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Two studies shed light on promising new ways to make kicking the habit easier, using both biology and behavior

Studies show that most smokers want to quit. So why are some people more successful at cutting out nicotine than others? The latest studies looking at the brains and behavior of smokers may provide some explanations.

Some people may be hardwired to have an easier time giving up their cigarettes, suggests one new trial described in the journal Neuropsychopharmacology. It turns out that some smokers start out with a particularly rich network of brain neurons in an area called the insula, which regulates cravings and urges and communicates cues: like seeing a cigarette or smelling tobacco smoke, then wanting to light up. Joseph McClernon, an associate professor of psychiatry and behavioral sciences at Duke University School of Medicine, ran MRI scans of 85 smokers who puffed more than 10 cigarettes a day. The smokers were then randomly assigned to continue smoking their brand or to smoke low-nicotine cigarettes, along with nicotine replacement therapy, for 30 days. All of the people in the study were then told to stop smoking and given nicotine replacement for 10 weeks.

MORE The Best Way to Quit Smoking Isn’t E-Cigs

Those who relapsed during that time tended to have lower activity in the insula, particularly in the connections between the insula and other motor areas that translate cravings into action, while those who successfully kicked the habit showed more robust activity in this brain region. The pattern remained strong despite how many cigarettes the smokers smoked.

“We’ve known for a while that some people seem to be able to quit and other people can’t,” says McClernon. “This gives us a better sense of what neural mechanisms might underlie those differences.”

The results suggest that it might be possible to identify people who may have a harder time quitting—a quick MRI scan of their brains would reveal how much activity they have in their insula—and provide them with more support in their attempts to quit. “Some smokers might benefit from more intensive, longer duration or even different types of interventions to stop smoking,” says McClernon. “They might need a higher, different level of care to help them make it through.”

But how much this system can be manipulated to help smokers quit isn’t clear yet. Previous studies show how potentially complicated the insula’s connections may be—smoking patients who have strokes and damage to the insula suddenly lose their desire to smoke and quit almost cold turkey. McClernon believes that the richer connections may not only promote interactions between cravings and behavior, but also enhance the connections that can inhibit or suppress those urges as well. Having a more intense communication in the insula may help strengthen the ability to quiet urges and inhibit the desire to smoke, despite cues and the urge to light up.

MORE Taking Medication May Make It Easier to Quit Smoking

But even if you’re not blessed with a brain that’s wired to make quitting easy, you still have options. In another study, published in the New England Journal of Medicine, scientists studied one of the oldest and most reliable ways to motivate people: money. In that trial, Dr. Scott Halpern from the University of Pennsylvania and his colleagues assigned 2,538 employees of CVS Caremark to one of five different smoking cessation programs. All received free access to nicotine replacement and behavioral therapy, and some were also assigned to an individual reward program in which they could earn up to $800 if they remained abstinent at six months. Another group was assigned another individual deposit program which was similar, except they had to pay $150 to participate, which they got back if they remained abstinent. Others were assigned to group versions of the reward and deposit programs so that what they received depended on how many in their group quit successfully.

Not shockingly, more people who were assigned to the reward program (90%) agreed to participate than people who were assigned to the deposit strategy (14%), likely because most people weren’t wiling to put their own money on the line. But when Halpern looked more closely at those who did enroll, the smokers in the deposit programs were twice as likely to be abstinent at six months than those in the reward group and five times as likely to be smoke-free than those who received only free counseling and nicotine replacement.

MORE Paying People Could Help Them Quit Smoking

That’s not entirely surprising, says Halpern, since having some of their own money at risk provided more motivation for the smokers to quit. When it comes to incentivizing smoking cessation, “adding a bit of stick is better than having just a pure carrot,” he says.

Finding the perfect balance of stick and carrot, however, may be more challenging. Halpern believes that from the perspective of an employer, insurer or government, offering even higher rewards than the $800 in the study and lowering the deposit slightly might still provide benefits to all parties. Smokers cost an average of $4,000 to $6,000 more each year in health services than non-smokers, he says, so offering even as much as $5,000 can still result in cost savings for employers, many of whom are now dangling financial incentives in front of their smoking employees to motivate them to quit.

How the financial carrot is proffered is also important, says Halpern. Now, most employers or insurers reward quitting in more hidden ways, with bonuses in direct deposit accounts or with lower premiums. While helpful, these aren’t as tangible to people, and humans respond better to instant gratification. “They’re rewarding people in ways that are essentially blind to the way human psychology works,” he says. “The fact that the benefits occur in the future make them a whole lot less influential than if people were handed money more quickly. Our work suggests that in addition to thinking about the size of the incentive, it’s fundamentally important to think about how to deliver that money.”

Another factor that can make financial incentives more powerful is to make the experience more enjoyable, either by introducing some competition in a group setting or encouraging smokers along the way. In the study, smokers in the group programs were not any more successful than those in the individual regimes, but that may be because the employees didn’t know each other. Grouping colleagues in the same office might have more of an effect, says Halpern. Either way, he says, incorporating such incentives to help more people quit smoking is “really a win-win.”

Read next: The Best Way to Quit Smoking Isn’t E-Cigs

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