TIME Research

This Is What’s Keeping Teens From Getting Enough Sleep

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The biggest factor keeping teens up at night isn't technology

Up to a third of teens in the U.S. don’t get enough sleep each night, and the loss of shut-eye negatively impacts their grades, mental well-being and physical health. Biologically, adolescents need fewer hours of slumber than kids — but there’s a bigger reason for teens’ sleep loss, according to a new study in the journal Pediatrics.

MORE: The Power of Sleep

Katherine Keyes, an assistant professor of epidemiology at Columbia University, looked at survey data from more than 270,000 eighth-, 10th- and 12th-grade students at 130 public and private schools across the country, gathered between 1991 and 2010. Each student was asked two questions about his or her sleep habits: how often they slept for at least seven hours a night, and how often they slept less than they should.

MORE: School Should Start Later So Teens Can Sleep, Urge Doctors

She found that over the 20-year study period, adolescents got less and less sleep. Part of that had to do with the fact that biologically, teens sleep less the older they get, but Keyes and her team also teased apart a period effect — meaning there were forces affecting all the students, at every age, that contributed to their sleeping fewer hours. This led to a marked drop in the average number of adolescents reporting at least seven hours of sleep nightly between 1991–1995 and 1996–2000.

That surprised Keyes, who expected to find sharper declines in sleep in more recent years with the proliferation of cell phones, tablets and social media. “I thought we would see decreases in sleep in more recent years, because so much has been written about teens being at risk with technologies that adversely affect the sleep health of this population,” she says. “But that’s not what we found.”

MORE: Here’s How Much Experts Think You Should Sleep Every Night

Instead, the rises in the mid-1990s corresponded with another widespread trend affecting most teens — the growth of childhood obesity. Obesity has been tied to health disturbances including sleep changes like sleep apnea, and “the decreases in sleep particularly in the 1990s across all ages corresponds to a time period when we also saw increases in pediatric obesity across all ages,” says Keyes. Since then, the sleep patterns haven’t worsened, but they haven’t improved either, which is concerning given the impact that long-term sleep disturbances can have on overall health.

Keyes also uncovered another worrying trend. Students in lower-income families and those belonging to racial and ethnic minorities were more likely to report getting fewer than seven hours of sleep regularly than white teens in higher-income households. But they also said they were getting enough sleep, revealing a failure of public-health messages to adequately inform all adolescent groups about how much sleep they need: about nine hours a night.

“When we first started looking at that data, I kept saying it had to be wrong,” says Keyes. “We were seeing completely opposite patterns. So our results show that health literacy around sleep are not only critical but that those messages are not adapted universally, especially not among higher-risk groups.”

TIME viral

Europe’s Oldest Woman Says Being Single Helped Her Live to 115

That and eating raw eggs

Emma Morano, Europe’s oldest woman, says eating raw eggs and staying single has kept her alive for over 115 years.

Morano told the New York Times that she’s been single since 1938, when her first and only marriage ended after the death of her infant child. (Divorce only became legal in Italy in 1970.) She’s had many suitors since but has rebuffed them all, she says, and attributes her longevity to staying single most of her life.

“I didn’t want to be dominated by anyone,” she said.

MORE: Meet the New Oldest American

Well, that and her diet: per the early recommendation of a doctor, she has eaten three raw eggs a day since she was a teenager.

Morano is the fifth oldest person in the world and has lived through two world wars as well as monarchy, fascism and democracy in Italy.

Read next: How to Live Longer

[NYT]

TIME Research

13 Ways Inflammation Can Affect Your Health

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You can't live without inflammation, but it can also be hazardous to your health

You’ve heard of anti-inflammatory medications and anti-inflammatory diets, but do you really know what inflammation is? In short, it’s the body’s response to outside threats like stress, infection, or toxic chemicals. When the immune system senses one of these dangers, it responds by activating proteins meant to protect cells and tissues. “In a healthy situation, inflammation serves as a good friend to our body,” says Mansour Mohamadzadeh, PhD, director of the Center for Inflammation and Mucosal Immunology at the University of Florida.” “But if immune cells start to overreact, that inflammation can be totally directed against us.” This type of harmful, chronic inflammation can have a number of causes, including a virus or bacteria, an autoimmune disorder, sugary and fatty foods, or the way you handle stress. Here are a few ways it can affect your health, both short-term and long.

It fights infection

Inflammation is most visible (and most beneficial) when it’s helping to repair a wound or fight off an illness: “You’ve noticed your body’s inflammatory response if you’ve ever had a fever or a sore throat with swollen glands,” says Timothy Denning, PhD, associate professor and immunology researcher at Georgia State University, or an infected cut that’s become red and warm to the touch. The swelling, redness, and warmth are signs that your immune system is sending white blood cells, immune cell-stimulating growth factors, and nutrients to the affected areas. In this sense, inflammation is a healthy and necessary function for healing. But this type of helpful inflammation is only temporary: when the infection or illness is gone, inflammation should go away as well.

It prepares you for battles

Another type of inflammation occurs in response to emotional stress. Instead of blood cells rushing to one part of the body, however, inflammatory markers called C-reactive proteins are released into the blood stream and travel throughout the body.

This is the body’s biological response to impending danger—a “flight or fight” response that floods you with adrenaline and could help you escape a life-threatening situation. But unrelenting stress over a long period of time—or dwelling on past stressful events—can cause C-reactive protein levels to be constantly elevated, which can be a factor in many chronic health conditions, like those on the following slides.

Read more: 14 Foods That Fight Inflammation

It can harm your gut

Many of the body’s immune cells cluster around the intestines, says Denning. Most of the time, those immune cells ignore the trillions of healthy bacteria that live in the gut. “But for some people, that tolerance seems to be broken,” says Denning, “and their immune cells begin to react to the bacteria, creating chronic inflammation.”

The immune cells can attack the digestive tract itself, an autoimmune condition known as inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn’s disease. The symptoms include diarrhea, cramps, ulcers, and may even require surgical removal of the intestines. Doctors aren’t exactly sure why some people get IBD, but genetics, environment, antibiotics, diet, and stress management all seem to play a role.

It can harm your joints

When inflammation occurs in the joints, it’s can cause serious damage. One joint-damaging condition is rheumatoid arthritis(RA)—another example of an autoimmune disorder that appears to have a genetic component, but is also linked to smoking, a lack of vitamin D, and other risk factors. A 2013 Yale University study, for example, found that a salty diet may contribute to the development of RA.

People with RA experience pain and stiffness in their inflamed joints. But because the immune reaction isn’t limited to the joints, says Denning, they’re also at higher risk for problems with their eyes and other body parts.

Read more: 10 Ways to Protect Your Joints from Damage

It’s linked to heart disease

Any part of your body that’s been injured or damaged can trigger inflammation, even the insides of blood vessels. The formation of fatty plaque in the arteries can trigger chronic inflammation. The fatty plaques attract white blood cells, grow larger, and can form blood clots, which can cause a heart attack. One specific protein, called interleukin-6 (IL-6), may play a key role, according to a 2012 study published in The Lancet.

Obesity and unhealthy eating increases inflammation in the body, but even otherwise healthy people who experience chronic inflammation because of an autoimmune disorder—such as rheumatoid arthritis, psoriasis, or celiac disease—appear to have a higher risk of heart disease, regardless of their weight or eating habits.

It’s linked to a higher risk of cancer

Chronic inflammation has been linked to cancers of the lung, esophagus, cervix, and digestive tract, among others. A 2014 Harvard University study found that obese teenagers with high levels of inflammation had a 63% increased risk of developing colorectal cancer during adulthood compared to their thinner peers. The inflammation may be due to obesity, a chronic infection, a chemical irritant, or chronic condition; all have been linked to a higher cancer risk.

“When immune cells begin to produce inflammation, immune regulation becomes deteriorated and it creates an optimal environment for cancer cells to grow,” says Mohamadzadeh.

It may sabotage your sleep

In a 2009 study from Case Western Reserve University, people who reported sleeping more or less than average had higher levels of inflammation-related proteins in their blood than those who said they slept about 7.6 hours a night. This research only established a correlation between the two (and not a cause-and-effect), so the study authors say they can’t be sure whether inflammation triggers long and short sleep duration or whether sleep duration triggers inflammation. It’s also possible that a different underlying issue, like chronic stress or disease, causes both. Shift work has also been found to increase inflammation in the body.

Read more: The Best Bedtime Routine for Better Sleep

It’s bad for your lungs

When inflammation occurs in the lungs, it can cause fluid accumulation and narrowing of the airways, making it difficult to breathe. Infections, asthma, and chronic obstructive pulmonary disease (COPD), which includes emphysema and chronic bronchitis, are all characterized by inflammation in the lungs.

Smoking, exposure to air pollution or household chemicals, being overweight, and even consumption of cured meats have been linked to lung inflammation.

It damages gums

Inflammation can also wreak havoc on your mouth in the form of periodontitis, a chronic inflammation of the gums caused by bacteria accumulation. This disease causes gums to recede and the skeletal structure around the teeth become weakened or damaged. Brushing and flossing regularly can prevent periodontitis, and one 2010 Harvard University study found that eating anti-inflammatory omega-3 fatty acids (such as fish or fish oil) may also help.

Periodontal disease doesn’t just affect oral health, either. Studies show that inflammation of the gums is linked to heart disease and dementia as well, since bacteria in the mouth may also trigger inflammation elsewhere in the body.

It makes weight loss more difficult

Obesity is a major cause of inflammation in the body, and losing weight is one of the most effective ways to fight it. But that’s sometimes easier said than done, because elevated levels of inflammation-related proteins can also make weight loss more difficult than it should be. For starters, chronic inflammation can influence hunger signals and slow down metabolism, so you eat more and burn fewer calories. Inflammation can also increase insulin resistance (which raises your risk for diabetes) and has been linked with future weight gain.

Read more: 14 Lifestyle Changes That Make You Look Younger

It damages bones

Inflammation throughout the body can interfere with bone growth and even promote increased bone loss, according to a 2009 review study published in the Journal of Endocrinology. Researchers suspect that inflammatory markers in the blood interrupt “remodeling”—an ongoing process in which old, damaged pieces of bone are replaced with new ones.

Inflammation of the gastrointestinal tract (as with inflammatory bowel disease) can be especially detrimental to bone health, because it can prevent absorption of important bone-building nutrients such as calcium and vitamin D. Another inflammatory disease, rheumatoid arthritis, can also have implications because it limits people’s physical activity and can keep them from performing weight-bearing, bone-strengthening exercises.

It affects your skin

The effects of inflammation aren’t just internal: They can also be reflected on your skin. Psoriasis, for example, is an inflammatory condition that occurs when the immune system causes skin cells to grow too quickly. A 2013 study published in JAMA Dermatology suggested that losing weight could help psoriasis patients find relief, since obesity contributes to inflammation.

Chronic inflammation has also been shown to contribute to faster cell aging in animal studies, and some experts believe it also plays a role (along with UV exposure and other environmental effects) in the formation of wrinkles and visible signs of aging.

It’s linked with depression

Inflammation in the brain may be linked to depression, according to a 2015 study published in JAMA Psychiatry; specifically, it may be responsible for depressive symptoms such as low mood, lack of appetite, and poor sleep. Previous research has found that people with depression have higher levels of inflammation in their blood, as well.

“Depression is a complex illness and we know that it takes more than one biological change to tip someone into an episode,” said Jeffrey Meyer, MD, senior author of the 2015 study, in a press release. “But we now believe that inflammation in the brain is one of these changes and that’s an important step forward.” Treating depression with anti-inflammatory medication may be one area of future research, he added.

Read more: 12 Strange-But-True Health Tips

This article originally appeared on Health.com.

TIME relationships

You Can Trick Someone Into Loving You — and 6 Other Surprising Facts About Love

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How to make somebody fall in love with you, get over an ex, and why you should treat your relationship like a drug addiction.

There are male dating gurus who train men in the dark art of the female putdown. They tell guys that playing hard to get is the way to make a woman fall head over heels; that women prefer men who behave like jerks, with a touch of humor thrown into the mix.

There is some truth to their claims: when we obtain what is hard to get, we appreciate it more. Sensing signs of love from a jerk may feel like more of an achievement than from a guy who constantly dotes on us (or on any woman he lays his eyes on). But these male dating gurus are not entirely right, either. Behaving like a jerk for too long builds resentment. Sometimes those negative feelings surface with a vengeance and we simply fall out of love, almost overnight.

Love advice spreads across the internet Gangnam-style, especially this time of year. But much of the advice on love – and breakups, for that matter – is little more than urban legend. Here are 7 surprising facts about the actual science of love and heartbreak.

You Actually Can Make Somebody Fall in Love With You

Dr. Arthur Aron made two strangers fall in love in a lab by staring into each other’s eyes for several minutes and taking turns answering 36 personal questions. (Things like, “What do you find most attractive in a woman/man?” and “If you were to die this evening, what would you most regret not having told someone?”) That experiment was replicated by two friends — now lovers — whose story was recently published in the New York Times. Why it works? The test creates intimacy, which can increase dopamine, one of the chemicals that floods the brain when you are in love.

You may be able to fool the brain with adrenaline, too. Adrenaline comes along with low levels of the feel-secure-and-safe chemical serotonin — just the right cocktail to fool the brain into producing feelings of love. In one famous study, a woman asked eligible strangers survey questions on a dangerous bridge and also safely on solid ground. Afterwards, she gave each of them her number. Who were more likely to call her later? The men on the bridge. Perhaps they had confused the adrenaline caused by the danger with the adrenaline caused by new love.

True Love Isn’t ‘Unconditional’

Newlyweds vow that they will love each other forever; that their love will never change. But they are deluded. Sexual desire and romantic love always fade. Scientists used to believe it would fade around the seven year mark. You know, that day you wake up next to your partner and suddenly feel like you’re in bed with a relative. But newer research shows that romantic love may fade even faster, even at just three years, according to recent research by the Pew Research Center and the National Survey of Families and Households. That doesn’t mean your relationship is doomed, of course. Just different. What keeps people together? Attachment. And altruism: a desire to keep our partner happy.

Marriage Isn’t Going to Solve Your Problems

In folklore, getting married is associated with happiness: an elegant white princess dress, a striking tuxedo, a wedding cake with marzipan flowers and the devoted man or woman you are going to spend the rest of your life with. A marriage may indeed signal happiness— a 2006 study in the Journal of Socio-Economics, which followed married couples over 17 years, found that happy people are more likely to get married than unhappy folks. But the marriage was not the cause of that happiness, these were naturally happy people. In reality, marriages do not make people happy. So don’t think a proposal is going to fix your relationship problems.

Love Hurts. Like, Physically Hurts

You want to fall in love, you say? Be careful what you wish for. Lovers might assume a broken arm may hurt more than a broken heart, but they’d be wrong. Emotional pain can feel just like physical pain by firing the very same neurons in the brain. Your heart can actually hurt.

And if you think love can’t kill you? Think again there, too. The idea of “broken heart syndrome” has been around for ages, but it’s a real condition — known as “stress cardiomyopathy” in the medical community. Heartbroken lovers with stress cardiomyopathy have two to three times as much adrenaline in their blood as people who suffer from a classic heart attack, and they have seven to thirty-four times more adrenaline than normal individuals. What that means? Taking a Tylenol actually might ease your emotional pain.

Instead of Trying to Forget Your Ex, Try Remembering Him

If Eternal Sunshine of the Spotless Mind weren’t fiction, I’d recommend erasing a few memories. But the path to recovery from a breakup may be just the opposite: don’t try to forget. Expose yourself to just about every reminder of your ex you can think of. Did he ride an Audi S5 Coupe? Go to an Audi store and test drive one. Keep going until the store manager asks you to get lost. The reason? Our brains get bored when we feed them the same information over and over. They adapt to the stimulants and eventually cease to take note – which enables to forget, and move on with our lives. This is true even if the information overload may be torturous at first.

Drastic Changes After a Breakup Can Help You Heal

It’s called “placement conditioning”: the idea that changing your surroundings may help you recuperate from heartbreak. The reason we know it works is because it’s been tested — in drug addicts. These weren’t heartbroken drug users, no, but love can be a lot like a drug: the reward chemical dopamine that plays a crucial role in drug addiction is overflowing in the brains of people smitten with love.

What explains the need for drastic changes is chemical conditioning. If a heroin addict always takes a dose at a specific time, in a specific hangout, the brain will learn that these stimuli (room, time, people) mean the dose is coming, and it will prepare itself for the fix. But suppose the heroin addict and his pals agree to quit. The withdrawal symptoms would be worse in the old environment because there the brain knows to prepare the body for a dose. When the fix doesn’t arrive, the cravings get stronger. When you are in emotional pain and crave your ex, you are in the same situation as the heroin addict who suddenly quits his addiction. His craving will be more intense in the “heroin” environment than in a new one. So get the ball rolling: move the love seat to the other side of the living room.

Go Out and Get Kinda Drunk After a Bad Breakup. No, Really

You may have heard the opposite, and even your shrink might warn against it — if she hasn’t caught up on the latest research. It takes time for the brain to store events to long-term memory. But there is an exception to this. When you experience something terrifyingly traumatic — which a breakup can be — the trauma leads to immediate memory storage. When you recall the negative memory it may continue to activate the amygdala, the brain’s fear processing center, on every recall. But there is a way to bypass this. If you get hammered right after the trauma, your memory of the event won’t be as tightly anchored in your brain. Excessive alcohol consumption naturally protects against this. So, go get drunk as a skunk. Just don’t don’t drink an unhealthy amount or do anything stupid.

Berit Brogaard is the author of the new book ON ROMANTIC LOVE: Simple Truths about a Complex Emotion (Oxford University Press). She is Professor of Philosophy at the University of Miami, where she specializes in philosophy of language, philosophy of mind, and the cognitive sciences.

TIME Diet/Nutrition

7 Surprising Ways To Eat Healthy at a Restaurant

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These simple, unexpected tricks help us make better menu choices

Here’s some food for thought: A typical restaurant meal contains more than 1,100 calories. If you’re like the average American, you eat out five times a week—which could wreak havoc on your diet. But before you vow to brown-bag it forever, know that it doesn’t have to be this way. Food economists and consumer behavior experts have been studying the habits of restaurant-goers to identify why some leave happily sated and others fall into a food coma. They’ve learned that menu choices may have as much to do with where you’re sitting as what you’re craving. A host of factors—from the room’s lighting to the height of your table—can encourage you to make more nutritious decisions. Here’s how to set yourself up to enjoy a waist-friendly meal to the fullest.

Read more: 20 Snacks That Burn Fat

Grab a health-minded pal

Research shows that when we eat in groups, we tend to order similar types of food: Everyone opts for a salad, say, or most of the table indulges in burgers. Food economists from Oklahoma State University found that diners who caved to this subtle peer pressure also tended to be happier with their choice. Looking for dinner dates? Round out your guest list with friends more likely to get a side of farro than fries.

Go somewhere romantic

Setting the mood seems to matter as much in a restaurant as in the bedroom. When researchers from the University of Illinois at Urbana-Champaign replaced a fast-food restaurant’s fluorescent lights and rock-and-roll soundtrack with softer incandescent bulbs and mellow jazz, study participants ate 18 percent less food. They also ate more slowly and rated the food as more enjoyable.

Read more: Healthy Foods That Can Kill You

Request a table near the window

“If you want to stack the deck in your favor, think twice about where you sit,” says Brian Wansink, PhD, director of Cornell University’s Food and Brand Lab and author of Slim by Design. When his team compared receipts and table locations at 27 restaurants, they found that patrons at high-top tables tended to order more fish and fewer desserts, and diners near the window were 80 percent more likely to have salads. “Maybe a high table makes you feel more in control, and sitting near a window feels more public,” he says. “The why isn’t clear. But as we say in the lab: If you want to be skinny, do what skinny people do.”

Sit far from the bar

When you’re in view of the television, it’s tempting to watch between bites. But eating while distracted causes people to consume more—not only at that meal but later in the day as well, according to a British study. And TV isn’t the only temptation you’ll fight near the bar. The Cornell research team found that groups of four perched within two tables of the booze drank an average of three more drinks than patrons just one table farther away.

Read more: 10 Signs Your House Is Making You Fat

Ask for a tall glass

We tend to underestimate how much liquid is in short tumblers—which is why bartenders typically pour 27 percent more alcohol into short glasses than tall ones, according to a study published in the Journal of Consumer Research. The flip side of this optical illusion: By sipping your caipirinha from a tall glass, you’ll have fewer calories without feeling deprived.

At a buffet, make a beeline for the fruit

“The first food a person selects triggers what they take next,” wrote researchers in a 2013 Plos One study on buffet patrons. For their experiment, they split 124 breakfast diners into two groups: One navigated a bar that started with cheesy eggs and ended with fruit; the other group faced a buffet table in the reverse order. Of the people who encountered cheesy eggs first, 76 percent served themselves the (deliciously gooey) calorie bomb—compared with 29 percent of people in the fruit-first group. And those who took cheesy eggs at the start were more likely to pile on bacon and potatoes. At dinner? Head to the salad station first.

Read more: 14 Fad Diets You Shouldn’t Try

Think miles, not calories

Calorie counts on a menu are a good start. But a 2014 study found that diners are even more motivated to order healthy when those numbers are translated into miles of physical activity. Every 100 calories is roughly equivalent to jogging one mile. The next time you’re waffling between a 600-calorie sandwich and an 800-calorie pizza slice, try thinking about the two extra miles it would take to run off the slice. (If you’re still craving the mozzarella and doughy goodness, it’s worth the calorie splurge.)

This article originally appeared on Health.com.

TIME Research

What Pheromones Really Reveal About Your Love Life

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In search of the lingua franca of odor

Beauty may not be in the eye of the beholder after all.

It may actually lie just south, in the nose. At least that’s what the latest research on pheromones, substances that social animals secrete to communicate with and attract other members of their species, suggests. Moths, pigs, goldfish, and even we, as social animals, have them. But exactly what role do these scents play in sexual attraction between people?

“There are millions of hits on websites that are trying to sell—mostly to men—the sex attractant,” says Charles Wysocki, a scientist at the Monell Chemical Senses Center. “Wear this and you’ll score tonight.” The promise: with the spritz of a mate-attracting mist, the sniffer would fall helplessly, chemically, scientifically under the smell spell of pheromone-emitting you.

Sounds good, but scientists have yet to conclusively identify a single known human pheromone, let alone bottle the stuff, although they have been chasing some fascinating leads. We now know, for example, that pheromones do help you smell someone else’s gender, and there’s some preliminary evidence that pheromones might be a potential X factor for attraction and fertility. According to one study, in which 18 professional lap dancers recorded their menstrual cycles, work shifts and tip earnings for two months, researchers found that during the phase when the women were most fertile, right before ovulation, dancers earned about $335 per shift, compared to $260 during other parts of their cycle. When they were menstruating, they only earned about $185 per shift. Interestingly, dancers who took birth control pills, which contain hormones that prevent ovulation, didn’t experience this fertile peak in tips.

Of course, many other explanations for the spike in sexual attractiveness are possible, but the data on the potential link between fertility and pheromones is getting hard to ignore. Another study published in Psychological Science found that when men smelled T-shirts worn by women who were close to ovulation, they displayed higher levels of testosterone than when they sniffed shirts from women further away from ovulation or T-shirts with a control scent.

Other research suggests that pheromones may regulate people’s moods, and that may explain the link—albeit more indirect—to sexual attraction. Wysocki’s lab collected underarm secretions from men and put them on the upper lips of women, who reported feeling less tense and more relaxed when they smelled the sweat than when they smelled a placebo.

Read more: Is Perfume Bad For Me?

What element of that sweat, or of any scent we emit that’s picked up by others, is driving the attraction is still unclear. Experts believe it may likely be a bunch of them. People also seem to have one-of-a-kind odor prints, or signature smells that we can’t help but produce uniquely. That’s thanks to something called a major histocompatibility complex (MHC), a collection of proteins that regulate the immune system—and maybe even mate choice, say some scientists. According to their theory, you naturally sniff out a mate whose immune system is optimally different from your own, which would make the immune system of your offspring more diverse, robust and better positioned to fend off more pathogens.

“The evidence is strong that there’s something in the major MHC genes that influences mate choice,” Wysocki says. In one study also involving well-worn T-shirts, women sniffed shirts worn by men and picked the one they’d most prefer to socialize with. They tended to select shirts from men with MHC genes that differed from their own. Women on birth control pills, however, show the opposite effect and are drawn to MHCs similar to theirs, possibly because the pill puts the body into a hormonal state similar to pregnancy, when you’d want safe, supportive and similar relatives around. Wysocki believes that birth control pills might be messing with the mating game. “Some have argued that for women who are on the birth control pill, they’re not getting the right olfactory information about their potential mate,” he says.

“We know that hormones affect the sense of smell especially in women,” Wysocki says. But he’s reluctant to say anything more about what role, if any they play in attraction, since results from studies so far aren’t conclusive, and the topic is controversial and tough to investigate well. “That’s about as far as I can say; the underlying mechanism has not yet been established.”

Part of the challenge comes from the fact that people perceive smells in different ways; one of Wysocki’s studies determined that no two people experience the olfactory world in exactly the same way. Add in all of the other complexities of attraction, and it’s no surprise we haven’t found an eau d’amour quite yet. That bottle may be many, many Valentine’s Days away.

Read next: The Truth About Aphrodisiacs

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TIME ebola

Ebola Bodies Are Infectious a Week After Death, Study Shows

The virus is also detectable in corpses for up to 10 weeks

Scientists have known for some time that the closer a person with Ebola is to death, the more infectious they are. A dead body with Ebola has been frequently referred to as a “viral bomb.” But what was unclear was how long bodies remained infectious. Now, researchers working for the National Institutes of Health in Hamilton, Montana released new findings on Thursday showing the Ebola virus may remain infectious in dead bodies for a week, and detectable for 1o weeks.

In the study, the researchers infected five macaque monkeys—a species they believe can serve as models for humans—with Ebola, then eventually euthanized them. They placed the dead monkeys in a temperature- and environment-controlled chamber to simulate the climate of West Africa. Over several weeks, the researchers sampled and swabbed the tissue of their nose, mouth, blood, lung, spleen, liver and muscle.

MORE TIME Person of the Year: Ebola Fighters

They concluded that infectious Ebola virus remained in the macaques’ organs for three days, and in their blood for seven days, after death. Viral RNA, which wasn’t infectious, was still detectable for 10 weeks.

The new findings underline the continued need for vigilance when burying the bodies of Ebola victims, as well as safer funeral practices. In the beginning of the current Ebola outbreak in West Africa, the spread of the virus could often be traced to funerals. Prior to massive education efforts, people living in the three affected countries often participated in intimate practices with the dead. In Liberia, for example, washing and kissing the corpse was a common custom.

The research also gives scientists a better understanding of how long the virus can remain in dead animals, since an outbreak is is typically spurred from contact between an infected animal and a human. It also provides a warning for researchers in the field who may handle primate carcasses, the researchers note.

Read next: How Today’s Ebola Response Reflects the History of Colonialism in Africa

Listen to the most important stories of the day.

TIME Sex/Relationships

6 Weird Things You Never Knew About Kissing

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Who knew kissing could make you healthier in so many ways?

Romantic kissing happens in more than 90% of all cultures, and with good reason: “It helps us find a partner and stay with them,” says Laura Berman, PhD, assistant clinical professor of ob-gyn and psychiatry at the Feinberg School of Medicine at Northwestern University in Chicago and author of Loving Sex ($25, amazon.com). But it also has a slew of surprising functions, including some major health benefits. Pucker up to these fascinating facts.

It may be the most fun way to build immunity

Just 10 seconds of French kissing can transfer 80 million germs from one person’s mouth to the other, according to a Dutch study published this past November in the journal Microbiome. While that may sound gross, there’s a big potential benefit. “It’s a way to pass around bugs so your body develops immunity to them,” Berman explains. In fact, a 2010 paper in the journal Medical Hypotheses suggested that kissing between partners could help protect their babies from being infected in utero with cytomegalovirus, which can cause birth defects such as infant blindness.

Read more: 13 Reasons to Have More Sex

It really is ‘in his kiss’

Women rate romantic kissing as more important when they’re close to ovulation—in other words, when they’re more likely to get pregnant. This makes sense from an evolutionary perspective, researchers say: Kissing offers a way to assess a mate through taste or smell.

It may boost your libido

While both sexes enjoy French kissing with long-term partners, guys “preferred more tongue contact” than women with short-term mates, according to a study published in the journal Evolutionary Psychology in 2007. (The study was done with college students, so you might want to take it with a grain of salt.) “One theory is that their saliva transfers testosterone to the woman, which in turn increases her sexual desire,” explains Berman.

Read more: 15 Everyday Habits to Boost Your Libido

It boosts happy hormones

“When you kiss, your brain releases this chemical that leaves you feeling connected and bonded to your mate,” explains Berman. It also releases endorphins, those same feel-good chemicals your body produces when you work out. Another relaxing bonus: kissing lowers levels of the stress hormone cortisol, according to a 2009 study done at Lafayette College in Pennsylvania.

It may save your relationship

Both men and women who report frequent kissing in their relationship report more sexual satisfaction, according to a 2011 Kinsey Institute study. Guys who frequently smooched were also three times happier in their relationship than guys with limited snuggling. (Interestingly, frequent kissing didn’t predict relationship satisfaction for women.)

It can last for days—literally

The longest kiss award goes to Ekkachai Tiranarat and Laksana Tiranarat, who smooched for 58 hours, 35 minutes and 58 seconds in Pattaya, Thailand, on February 12-14, 2013. They beat out eight other couples who entered the competition. Wonder how much training they had to do to prepare for that one!

Read more: 20 Ways to Fall in Love All Over Again

This article originally appeared on Health.com.

TIME public health

Canada Has a Case of Mad Cow Disease

Cattle graze in a pasture in the foothills of the Rocky Mountains west of Calgary, Alberta in 2006.
Patrick Price—Reuters Cattle graze in a pasture in the foothills of the Rocky Mountains west of Calgary, Alberta in 2006.

One Alberta cow has been diagnosed

A beef cow in Canada was found to have mad cow disease, officials said Friday, the first case of the disease in the country since 2011.

The Canadian Food Inspection Agency (CFIA) is investigating the cow’s history, Reuters reports, and officials said the infected cow hadn’t been processed for consumption by humans or other animals. Cows are typically infected after eating materials from the brains or spinal cords of sick animals. When humans eat an infected cow, they can become ill with a variation of the disease.

Officials said this case should not impact Canada’s beef exports.

[Reuters]

TIME Infectious Disease

Disneyland Asked California to Say Park Was Safe During Measles Outbreak, Report Says

Visitors walk towards the Sleeping Beauty Castle during a visit to the Disneyland Paris Resort run by EuroDisney S.C.A in Marne-la-Vallee on Jan. 21, 2015.
Gonzalo Fuentes—Reuters Visitors walk towards the Sleeping Beauty Castle during a visit to the Disneyland Paris Resort run by EuroDisney S.C.A in Marne-la-Vallee on Jan. 21, 2015.

The AP reports Disneyland officials sent emails to officials about language to use when talking about the park, outbreak

Disneyland asked California officials to reassure the public that the amusement park was safe to attend amid the measles outbreak that started there in December, according to a new report.

The Associated Press, citing documents obtained, reports that Disneyland officials sent a series of emails to the California Department of Health and the Orange County Health Care Agency, asking the agencies to make it clear to the public that the park was not responsible for the outbreak, and that vaccinated people could still visit. Six Disneyland employees were among 70 people in California infected during an outbreak that has passed 100 cases in the U.S.

A Disneyland spokeswoman told the AP the park was in contact with health officials “in order to ensure that factual and accurate information flowed both ways to avoid confusion and properly inform the public.”

Read more at the Associated Press

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