Research

“The chemicals used to make hand sanitizers, soaps, lotions, and sunscreen degrade the skin’s ability to act as a barrier"

An order of French fries may be bad for your health in ways that extend well beyond the outsize calorie count. According to a new study by scientists at the University of Missouri, people who used hand sanitizer, touched a cash register receipt and then ate French fries were quickly exposed to high levels of bisphenol A (BPA), a chemical widely used to coat receipt paper.

BPA has been identified as an endocrine disrupting chemical for its ability to interfere with estrogen and other hormones. In human and animal studies, BPA exposure has been linked to adverse effects on the reproductive and neurological systems as well as increased risk for obesity, diabetes and cardiovascular disease. Some animal studies also suggest that BPA can set the stage for certain cancers, including breast and prostate cancer.

The study, published in PLOS One, is the first to show how handling BPA-coated receipts can account for exposure at levels that have been shown to harm health.

Most studies of BPA exposure, including those that have informed current regulation of the chemical, have focused on exposure that happens through food or after BPA passes through the gut, explains study author Frederick S. vom Saal, Professor of Biological Sciences at the University of Missouri-Columbia.

But this study shows that skin absorption of BPA appears to lead to higher levels of biologically active BPA in the body than when the chemical is digested with food. When scientists added in two other factors—scrubbing hands with hand sanitizer and eating greasy food—the evidence points to a super-sized dose of BPA.

“The chemicals used to make hand sanitizers, soaps, lotions, and sunscreen degrade the skin’s ability to act as a barrier and so act as skin penetration enhancers,” says vom Saal. So BPA enters the body more efficiently than it would otherwise. Food grease and other oils can act similarly because BPA itself is fat-soluble, explains vom Saal.

Vom Saal also explains that BPA can be absorbed rapidly by tissue in the mouth so that the chemical enters the body without first being metabolized–or broken down in digestion.

“The combination of dermal and oral BPA absorption led to a rapid and dramatic average maximum increase in unconjugated (bioactive) BPA…in blood and urine within 90 minutes,” write the study authors. In experiments, BPA was absorbed by people who held a receipt for as little as two seconds. The amounts absorbed in the study “are in a zone where effects associated with obesity, diabetes and neurological effects can result,” says vom Saal.

Many laboratory studies have shown that BPA can produce health effects at very low levels of exposure—or just a few parts per trillion. BPA has also been shown to effect developing embryos, which means a mother’s exposure to BPA can affect her children. Some studies have shown that a single BPA exposure can affect even a third generation as the chemical has the potential to alter the ovary and eggs of the exposed fetus. At the same time many studies have found associations between BPA exposure in humans and the health effects found in lab studies.

Given the concern about BPA’s health effects, manufacturers of baby bottles and toddler’s sippy cups have largely stopped using it. In 2012, the U.S. Food and Drug Administration withdrew its approval for use of BPA in these products. But its use is still allowed in other products that come into contact with food. Industry trade associations, including the American Chemistry Council, maintain that BPA is safe and that average exposure levels, including from receipts, are not harmful.

Meanwhile, 12 different states have passed laws barring BPA in various products—primarily food and beverage containers intended for use by children. Only one state, Connecticut, has passed a law banning use of BPA in receipts.

But simply switching to another chemical may not solve the problem. As vom Saal and his coauthors point out in this study, a common BPA alternative used in receipts is bisphenol S, which can also interfere with estrogen. In fact, in its assessment of available alternatives for receipts, the U.S. Environmental Protection Agency found no chemical that was clearly safer than BPA. “What we need,” says vom Saal, “is an alternate technology.”

In the meantime, it appears that grabbing the fast food receipt before snacking on French fries may not only be packing on the extra calories. It might also be disrupting our hormones.

This post originally appeared on CivilEats.com.

A quarter of schools don't educate their athletes on the injury

Policies guiding concussion treatment at scores of colleges across the country still run afoul of rules set by the National Collegiate Athletic Association (NCAA), according to a new study in The American Journal of Sports Medicine.

“The vast majority of schools did have a concussion management plan, but not all of them did,” said Christine Baugh, a Harvard researcher and one of the study’s co-authors. “The number of schools who reported to us that they didn’t have a concussion management plan in place affects tens of thousands of athletes each year.”

The study comes as the NCAA faces increased pressure to protect the health of college athletes. Earlier this year, the organization set aside $70 million for concussion testing and research to settle several class action lawsuits. The exact number of college athletes who suffer from concussions during practice and games is unclear, but some estimates put it in the thousands.

To combat concussions, the NCAA has mandated that colleges create “concussion management plans.” While 93% of the 2,600 schools surveyed said they had drafted such a plan to guide their response to concussions, many of those plans lacked components that Baugh says are critical to actually reducing the head injury. For one, about a quarter of schools don’t train athletes to detect concussions, making it difficult for athletes to recognize when they need to seek medical attention. And more than 6 percent of schools allow coaches or athletes who lack formal medical training to make the final decision about whether a student can return to competition after suffering a concussion.

“It may be the case that coaches and athletes are being extra cautious; despite being cleared by a clinician, they are withholding themselves or withholding their athletes,” said Baugh, who was a Division I athlete during her college years. “But it may also be the case that some of these schools, coaches or athletes are pressuring clinicians to prematurely return to play before their symptoms have been resolved.”

The study concludes with a recommendation for the NCAA: step up enforcement of concussion policies.

Two thirds of recalled supplements still contain the substance banned by the FDA

Dietary supplements with recalled ingredients often remain on the shelves despite a health warning from the Food and Drug Administration (FDA), according to a new study in the Journal of the American Medical Association.

Looking at 27 supplements recalled between 2009 and 2012, researchers found that two thirds of those supplements what were still being sold contained the substance banned by the FDA. The other supplements either remained on the shelf with the recalled ingredient removed or were pulled completely.

The study also found that some types of supplements were more likely to contain recalled ingredients than others. Sports supplements stayed on the shelf despite containing recalled ingredients 85% of the time, higher than any other type of supplement. Only 20% of sexual enhancement supplements that had faced a recall continued to be sold with the recalled element still included, the study found.

Supplement manufacturers make varying levels of effort to ensure that their recalled product is taken off the shelves, says Pieter Cohen, a Harvard researcher who helped conduct the study.

“These companies…were so unabashedly willing to continue to sell exactly the same product that they had recalled with banned drugs in them,” he says. “It shows that the FDA is not … double checking.”

And just what is that cracking sound, anyway?

From fingers and toes to necks and knees, everyone knows a “cracker.” And most habitual joint poppers have heard rumors their habit may cause arthritis. But are those rumors true?

First, a quick anatomy lesson: Many of your joints—including those that allow your fingers to beckon or point—feature small pockets or gaps that are filled with synovial fluid. Like axle grease, this fluid allows the bones that commingle in your joints to glide close to one another without grating, explains Dr. Pedro Beredjiklian, chief of hand and wrist surgery at Philadelphia’s Rothman Institute.

When you pull, twist or otherwise “crack” a joint, you’re expanding the volume of space between your bones, Beredjiklian says. That volume expansion creates negative pressure, which sucks the synovial fluid into the newly created space. This sudden inflow of fluid is the popping you feel and hear when you crack a knuckle, he adds.

The more you crack your joint, the more you stretch and loosen both its capsule and the surrounding ligaments. And the looser those components become, the more easily your joint will pop, Beredjiklian says.

So is this bad for your joints? Almost certainly not, he assures. Multiple studies have looked into the prevalence of “crackers” among large groups of osteoarthritis patients. They found no evidence that finger pullers and poppers are more likely to suffer from arthritis than those who don’t crack their knuckles. One devoted researcher—a man who habitually cracked the joints on his left hand—actually studied himself. After roughly six decades of lopsided joint popping, this case study of one showed no increased presence of arthritis in his left hand as opposed to his right.

“Finger cracking is so common you would expect to see a lot of causal reports if it was harmful,” Beredjiklian says. “But you don’t. So I think it’s unlikely cracking joints in hands leads to arthritis.”

While one 1990 study linked long-term joint popping to hand swelling and lower grip strength, there isn’t any more research to back up that finding. On the other hand (pun intended), at least one study concluded that knuckle cracking offers those who do it a sense of almost therapeutic “release.”

Poppers, you can ignore your fusty aunt or cranky coworker when they try to scare you with talk of debilitating cracking-related ailments.

Just one note of caution: Tendons catching on irregular bone or joint formations can also explain some clicking or popping sounds, especially in places like your neck, Beredjiklian says. Whether this can cause harm will depend on the person and his or her anatomy. But if a weird sound emanates from your shoulder or knee when you flex it a certain way, you may want to avoid angering that area with deliberate cracking.

Not being able to smell well could signal the early stages of Alzheimer’s disease

No one appreciates their sense of smell when they pass a trash heap or accidentally step in dog poop. But your nose knows a lot—not just when things stink. In fact, your ability to smell, or not, can tell you a lot about your health. Here’s why you shouldn’t take your whiffing powers for granted.

A bad sense of smell can signal an early death

Feel like your sense of smell has gone south over the years? If it’s less than stellar, it could be a tip-off that you’re not in good health. A new study from the University of Chicago Medical Center found that not being able to detect certain odors had an increased risk of dying within five years. A whopping 39% of older patients who couldn’t pick up on scents like orange, rose, and peppermint died within that time frame, compared to only 19% of so-so smellers, and 10% of good smellers.

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Poor smell detection may be a sign of Alzheimer’s

Not being able to smell well could signal the early stages of Alzheimer’s disease, according a Harvard Medical School study. Participants with elevated levels of amyloid plaques (telltale proteins found in the brains of Alzheimer’s patients) who performed worse on an odor identification test also had greater brain cell death. Why? When the disease starts to kill brain cells, this often includes cells crucial for your sense of smell.

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Smelling something weird could predict a stroke

Some people pick up on more scents than others, but brief episodes of smelling something completely off-base—like fish when there isn’t any around—may be a sign of stroke or a seizure. The American Academy of Neurology says these “olfactory hallucinations” are usually unpleasant smells, but they can differ from person to person, according to the Mayo Clinic. Contact your doctor right away if your nose seems to be going haywire.

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Imagining odors can precede a migraine

While it’s relatively uncommon, people may also hallucinate a smell as part of a pre-migraine aura, according to a review of research done by the Montefiore Headache Center. Again, the scents were mostly unpleasant: the most common were of things burning or decomposing.

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This article originally appeared on Health.com

Up to an additional 150,000 to 180,000 per year between 2007 and 2009

The recession was accompanied by a sharp increase in the number of American men who underwent vasectomies, according to research presented Monday, though it’s unclear if economic woes actually led to more procedures.

Researchers from Weill Cornell Medical College looked at survey data from the National Survey for Family Growth, which interviewed more than 10,000 men between 2006 and 2010, according to the American Society for Reproductive Medicine. They wanted to get a sense of how the economic downturn from 2007 to 2009 affected men’s decisions about having kids.

Before the recession, 3.9% of men reported having a vasectomy, but 4.4% reported having one afterward, which the researchers calculated to mean an additional 150,000 to 180,000 vasectomies during each year of the recession.

The researchers also found after the recession that men were less likely to be employed full-time, and more likely to have lower incomes and be without health insurance. Nothing changed when it came to men’s desire to have children, but those who were interviewed after the recession were more likely to want fewer children.

It’s important to note that the study, which is being presented at the American Society for Reproductive Medicine’s 70th Annual Meeting, does not prove causation, meaning it’s unclear whether men were undergoing surgery for financial reasons. Though the researchers do conclude that their findings suggest Americans may be factoring economics into family planning—which is not necessarily a new trend.

When kids learn how far they’d have to walk to burn off the calories in a soda, they tend to buy smaller sizes or stop buying it altogether, suggests a new study published in the American Journal of Public Health.

Researchers analyzed more than 3,000 drink purchases by children ages 7 to 18 at stores in low-income Baltimore neighborhoods and found that sugary drinks accounted for 98% of the beverages kids bought. But when researchers put up colorful signs with calorie information, that figure dropped to 89%. The most effective sign was the one that said it would take a five-mile walk to burn off the calories in the drink. Researchers argue that while laws already require beverage manufacturers to post caloric information, calorie numbers may not mean all that much to many consumers. More practical information, including statistics about how long it will take to burn calories, is easier to grasp.

“This is a very low-cost way to get children old enough to make their own purchases to drink fewer sugar-sweetened beverages, and they appear to be effective even after they are removed,” says study author Sara N. Bleich, an associate professor at Johns Hopkins University.

MORE: The Soda Industry’s Promises Mean Nothing

Sugar-sweetened beverages like sodas and energy drinks contribute significantly to a number of public health ailments that harm children, including obesity. In low-income communities the problem is especially rampant: Sugary drink consumption accounts for about 15% of a minority adolescent’s caloric intake, more than twice the recommended quantity. Interventions like this might help decrease that disparity.

“People don’t really understand what it means to say a typical soda has 250 calories,” says Bleich. “If you’re going to give people calorie information, there’s probably a better way to do it.”

Read next: The Soda Industry’s Promises Mean Nothing

Life expectancy in the U.S. is at an all-time high, according to a recent report by the Centers for Disease Control and Prevention (CDC). And while the news that we’re living, on average, to the ripe old age of 78 years and 9 ½ months isn’t that surprising, there is one stat that is: A girl born in 2012 can expect to live to 81.2 years—almost 5 years longer than a boy baby born the same year, who’s likely live to age 76.4. Weaker sex, indeed.

“Men are biologically and sociologically at a disadvantage from the time they’re conceived to the time they die,” says Marianne Legato, MD, professor emerita of clinical medicine at Columbia University College of Physicians and Surgeons and founder and director of the Foundation for Gender-Specific Medicine. Here’s why:

Females are tougher in utero

Two and a half as many boys are conceived as girls, Dr. Legato says, but they’re so much more likely to succumb to prenatal infection or other issues in the womb that by the time they’re born, the ratio is close to one to one. “They’re also slower to develop physically than girls prenatally, which means they’re more likely to die if they are preemies due to underdeveloped lung or brain development,” Dr. Legato explains.

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Women are less likely to be daredevils

Unintentional injuries are the third leading cause of death in men, according to the CDC; for women it’s only the sixth. Again, you can blame it on biology: The frontal lobes of the brain—which deal with responsibility and risk calculation—develop much more slowly in males than females, Dr. Legato says.

The result: Guys often take many more risks (which you probably already realize if your small son has taken one too many spins off his bike handlebars). “Almost inevitably, a male will take risks that a woman of his same age wouldn’t take,” Dr. Legato says.

Women succumb to heart disease later

Heart disease is the leading killer of both men and women, but men are more likely to develop it—and die from it—as early as their 30s and 40s. Women, on the other hand, typically develop heart disease 10 years later than men. They’re protected from it until menopause, since their bodies churn out estrogen, which helps keep arteries strong and flexible, says Dr. Legato.

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Women have stronger social networks

Friends make good medicine: People with strong social connections have a 50% lower chance of dying than those with few social ties, according to a 2010 study at Brigham Young University. “Most men tend to hold their stress and worries close to their chest, while women tend to reach out and talk to others,” Dr. Legato explains. The one exception: married men, which also explains why so many studies show that they’re likely to be healthier and live longer.

HEALTH.COM: How Friends Make You Healthier

Women take better care of their health

Men are 24% less likely than women to have visited a doctor within the past year and are 22% more likely to skip out on cholesterol testing, according to the Agency for Healthcare Research and Quality. In fact more than a quarter (28%) of men don’t have a regular physician and about one in five didn’t have health insurance in 2012, according to the Kaiser Family Foundation.

You can blame it on the so-called John Wayne syndrome: “Men often deny illness; they minimize symptoms because they don’t want to go to a doctor and find out something is wrong,” Dr. Legato notes.

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This article originally appeared on Health.com