TIME medicine

Dad Bod Is Explained By Science In a New Study

A first-of-its kind study to follow men for up to 20 years from adolescence shows that dads do get a little squishier after the kids

According to Clemson student Mackenzie Pearson, who wrote a viral essay essay on the appeal of the dad bod, it’s a physique that’s a “nice balance between a beer gut and working out,” the result of going to gym but indulging in a few pizzas once in a while and being okay with that. (Think John Hamm, and Chris Pratt before he went Jurassic.)

And according to scientists, Pearson and her demographic have pretty much nailed it. The source of that “more human, natural and attractive” body is unique to fathers and can be traced to simply having kids.

In a study published in the American Journal of Men’s Health, Dr. Craig Garfield, a pediatrician at Northwestern University Feinberg School of Medicine and his colleagues dove into a database of 10,263 men beginning when they were 12 years old and followed them for up to 20 years. They looked specifically at how body mass index (BMI), a combination of height and weight, changed over time as the men either became fathers or did not, and for those who did, whether they were what the researchers called resident fathers who lived with their children, or non-residents who lived separately.

Read more Why We Accept ‘Dad Bod’ on Rich Men

Whether or not they lived with their kids, becoming a father was linked to around a four pound increase in weight over the study period, while remaining child-free was associated with a 1.4 pound weight loss for a six-foot-tall man.

“It’s a unique look at the influence that a social phenomenon, becoming a father, has on a biological marker, namely BMI,” says Garfield. “It really plants fatherhood as a potential social determinant of health for men.”

That’s a critical finding, especially since men, and in particular young men, are typically less proactive about taking care of their health. Garfield notes that while many men will quit smoking and drink less and otherwise try to become healthier when they become fathers, there may be other factors associated with caring for kids that counteract those good intentions, such as being surrounded by more kid-friendly, high calorie foods and snacks, as well as their leftovers.

“From my own point of view, we wouldn’t have as many pizzas in the house if the kids weren’t around, and we wouldn’t have the brownies my wife makes if the kids weren’t around,” says Garfield. “Having kids around changes not only the food in the house and what is available to you for meal, but also for snacks. It also changes whether you are able to find time to get out and exercise and get enough sleep and take care of yourself.”

Read more Dadbod, Mombod and Our Pretty Bad Bod Prob

Dads, of course, are not alone in experiencing these effects of parenthood. But this is the first study to tease out specifically the effects of fatherhood on weight gain over time. Since men are less likely to be seeing doctors regularly, if they are joining their partners during prenatal visits or pediatric visits, says Garfield, those are good opportunities to talk to them about their own eating, exercise and sleep habits to make them aware of the sneaky way that pounds can creep up on dads and potentially affect their health (even if the look seems to have its own kind of physical appeal).

Read next: For the Dad Who Is Confident About How He Looks in Swim Trunks

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TIME Research

Alzheimer’s May Show Up in Saliva

Identifying Alzheimer’s well before symptoms appear may become easier with a saliva test

The latest advances in Alzheimer’s disease involve people who don’t appear to show any signs of cognitive decline yet. Experts now believe that the biological processes behind the neurodegenerative condition begin years, if not decades, before memory problems and confusion become noticeable.

At the annual Alzheimer’s Association International Conference, researchers say they have found a series of substances in saliva that can distinguish between people who experience normal aging, those with mild cognitive dementia (MCI, which in some cases can lead to Alzheimer’s and in other cases not), and Alzheimer’s disease.

Presenting at the meeting, Shraddha Sapkota, a graduate student in neuroscience at University of Alberta, and her colleagues described how they carefully analyzed the saliva of a group of volunteers participating in an aging study. Some had been diagnosed with Alzheimer’s and some with MCI, while others did not have any neurological conditions. By comparing their saliva components, the scientists found that each of the three groups showed slightly different patterns of compounds, which could form the basis of a relatively easy and non-invasive way to determine which people are at higher risk of developing more serious degenerative brain conditions.

The results aren’t conclusive enough yet for doctors to start using them to distinguish people who are more likely to develop Alzheimer’s, but that’s the goal, says Sapkota. Ideally, for example, isolating those with MCI might help doctors to focus in on a group of patients who might be at higher risk of developing Alzheimer’s and therefore might need more intensive and regular testing.

TIME Research

Your School Grades Affect Your Risk of Dementia

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Building up a dementia-resistant brain and protecting against Alzheimer’s begins a early as childhood, the latest research suggests

In a presentation at the Alzheimer’s Association International Conference, scientists report that getting good grades in school is among the important factors that can protect against dementia later in life.

Experts have known that people with so-called cognitive reserve, or the ability to compensate for the failing parts of the brain in degenerative conditions such as Alzheimer’s, can help to slow down or stave off some symptoms of memory loss, confusion and disorientation. But it wasn’t clear when the buildup of these reserves should begin.

MORE: New Research on Understanding Alzheimer’s

In a study involving 7,574 people who were at least 65 years old and followed for 21 years, Serhiy Dekhtyar, a postdoctoral research fellow at the Karolinska Institute, and his colleagues found that the chance of developing dementia was strongly linked to how well the people in the study did in school during childhood. Those with grades in the lowest 20% showed the highest risk of developing dementia later on, an effect that remained strong even if the volunteers went on to attain more education and had intellectually demanding jobs. In other words, says Dekhtyar, “Your early life baseline cognitive abilities play a role in later dementia risk, which we didn’t know before because we didn’t have data. Now we have the data that show there is a component of early cognitive abilities that seems to still [have an effect] 50 or 60 years later.”

Most studies focus on people who already have dementia and look at the effect that intellectual engagement in later life can have in slowing the progression of dementia or reducing some of its symptoms. The idea is that the more intellectual activities the brain has, the stronger and more robust its network of neurons. Someone with larger cognitive reserves, therefore, can function with fewer symptoms than someone with lesser reserves, even if both have the same amount of damage caused by degenerative diseases like Alzheimer’s.

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

Those with the most protection in the study were people who had good grades during childhood and who ended up in demanding jobs; they lowered their risk of dementia by about 40%. While having a complex intellectual job lowered risk of dementia by 23%, it couldn’t completely negate the effects of not being a good student in school. “If you were in a group at higher risk, then it might be difficult to modulate that risk,” says Dekhtyar. “But it’s not deterministic. We can clearly see that risk can additionally be reduced, just not by as much as if you started with a lower baseline risk.”

For doctors and people concerned about their dementia risk, especially those in families in which several members are already affected by the condition, it’s important to understand that protection against dementia begins early. And even if it’s too late to become more engaged in school, continuing to build cognitive reserve with an intellectually demanding job, staying socially active and mentally engaged, can be helpful as well. “It’s a good message that I think has to be out there for patients,” says Dekhtyar.

TIME Cancer

Here’s the Amount of Exercise That Lowers Breast Cancer Risk

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A new study calculates how much weekly exercise can reduce fat levels enough to lower the chances of developing breast cancer

More than 100 studies have found that physical activity can lower breast cancer risk; the most active women tend to have a 25% lower chance of developing the disease than the least active women. But how does exercise help?

Christine Friedenreich, scientific leader of cancer epidemiology and prevention research at Alberta Health Services, and her colleagues had identified body fat as a possible pathway to lowering cancer risk. In an earlier study, they found that women exercising 225 minutes a week showed dramatic drops in total body fat, abdominal fat and other adiposity measures.

MORE: New Genetic Test for Breast Cancer Would Be Cheaper and Easier

That inspired the team to examine more closely the effects of the commonly recommended 150 minutes of moderate to vigorous exercise a week on body fat measures. They compared these effects to a doubling of that amount of activity, to 300 minutes a week, to see if more exercise had a greater effect in lowering body fat.

Reporting in JAMA Oncology, Friedenreich found that indeed, among 384 non-active women past menopause, some of whom were normal weight and others who were overweight or obese, those randomly assigned to exercise for 300 minutes a week over the year-long study lost more body fat than those who were active for 150 minutes each week. The women didn’t change their diet or any other aspect of their lives; they just exercised their allotted amount, by walking, running, cycling or using an elliptical machine or treadmill.

MORE: Many Breast Cancer Patients Get Unnecessary Radiation

Overall, the women exercising 300 minutes weekly lost 1 kg—about 2.2 pounds—or 1% more body fat than those in the 150 minute group. The former also lost more abdominal fat and had a bigger drop in their waist to hip ratio. They did not, however, lose significantly more weight.

That last finding is important because many physical activity and cancer studies focus on weight as an outcome and correlate pounds lost with cancer risk. But Friedenreich wanted to specifically tease apart what physiologic effects exercise has on the body, specifically on fat, since fat levels have been linked to a higher risk of a number of cancers, including breast cancer.

MORE: Here’s How Well Your Genes Can Predict Your Breast Cancer Risk

While the women who exercised more saw the biggest drops in their body fat measures, those who followed the recommended amount of activity—150 minutes each week—also melted away some of their fat. But the finding suggests that more is better, and for preventing cancer, it may take more than the recommended amount of exercise to produce a benefit.

“The exercise guidelines were developed with [heart disease] outcomes in mind,” says Friedenreich. “So at that level, they can have an effect on blood pressure, cholesterol levels and waist circumference. But for cancer prevention, we may need to exercise at higher volumes. So yes, doing 150 minutes of activity a week is good, but if you can do more, then from a cancer prevention perspective, 300 minutes is better.”

The fact that exercise can lead to a drop in body fat is especially important for cancer of the breast, she says, since fatty tissue is the primary source of hormones that can drive breast cancer after menopause. Fat also plays a role in the body’s immune and inflammatory responses, both of which are also involved in cancer. “I’m sure that doctors are advising their patients to be more physically active to prevent heart disease or diabetes,” says Friedenreich. “So we’d like to add cancer to that list of chronic diseases that exercise can potentially prevent or help to lower the risk.”

TIME Brain

How Alzheimer’s Is Different in African-Americans

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The brain disease looks very different in African-Americans than it does in whites, which could affect treatment and diagnosis

The hallmark signs of Alzheimer’s are well-established—plaques of amyloid protein and tangles of tau protein in the brain, which work to suffocate and eventually destroy neurons that are dedicated to higher level functions such as memory and reasoning.

But in a study published in the journal Neurology, researchers show that there may be important differences in the way Alzheimer’s appears in the brains of African-American and white patients. When Lisa Barnes, a neurologist at the Rush Alzheimer’s Disease Center at Rush University Medical Center and her colleagues compared the brains of 41 black patients who had died of the disease to the brains of 81 white patients, they found a much more complex picture of Alzheimer’s in the brains of the African-Americans.

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

These patients were more likely to have not just the familiar plaques and tangles, but also other signs of neurological abnormalities, including Lewy bodies, signs of infarcts and blood vessel disease. In fact, 71% of the African-American patients showed this mixed picture compared to 50% of the white patients.

The most common—and surprising, says Barnes—connection involved the Lewy bodies. These are clumps of proteins that aggregate inside nerve cells, particularly those involved in movement. They are common in Parkinson’s patients and can contribute to tremors as well as hallucinations and sleep disruptions. Because the black population is known to have higher risk of circulatory disorders, including stroke and hypertension, Barnes expected to find more infarct-related differences when comparing the brains of African-Americans to those of whites. “We did not find that,” she says. “We found a much more mixed picture than just infarcts, and that was a little bit surprising.”

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

She says, however, that the prevalence of Lewy bodies in the brains might simply reflect a bias in the study sample, since they came from the population of patients who came to the Alzheimer’s clinic. Hallucinations and abnormal movements are more likely to cause patients to see a doctor than slips in memory, which many dismiss as a normal part of aging.

Still, Barnes says the findings suggest that there may be important differences in the way Alzheimer’s develops in African-Americans that is being missed with the dominant focus on plaques and tangles. “They suggest that treatments currently on the market targeting plaques and tangles, if they are given to a population that has more mixed disease, may not respond as well to the medication,” she says. “Right now we are focused on amyloid and tangles. But maybe we need to be thinking about Lewy bodies and infarcts as possible treatment targets.”

It’s possible, for example, that in African-American patients, a combination of drugs that includes other medications to treat blood pressure or diabetes might be as important for addressing symptoms of dementia.

The results also suggest that having better ways of detecting not just the plaques and tangles but other changing brain abnormalities, particularly in non-white populations, are desperately needed. But Barnes says that little is known about how brain disorders evolve in different racial and ethnic groups because there are very few studies involving them. “We need to have better biomarkers—something to actually detect things in the body, blood and brain to help us see how the disease is playing out in different racial and ethnic groups,” she says. “But we need people participating in the studies to do that.”

TIME Research

Hair Burning Is Now a Thing

This is This Is Now A Thing, where we check out the science behind new health phenomena.

Friday treat 🔥🔥🔥 @lacesandhair @crisdioslaces #hairtreatment #hidratação #multivitaminas

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The thing: Candle cutting, or the Brazilian term, velaterapia, is a $150 to $200 hair treatment that involves running a candle flame along twisted strands of hair to singe off stray and unhealthy ends.

Popular for decades in South America, velaterapia possibly originated in ancient civilizations among pioneering beauties such as Cleopatra, who supposedly had her locks singed regularly to get that thick, glossy, waterfall look for which she was known. Stylists twist modern-day tresses into dozens of strands, dreadlock-style, and then run a lit candle along each one, holding the flame just long enough for the stray ends to briefly catch fire and burn off.

Ricardo Gomes, a stylist at New York’s Maria Bonita salon, performs the service. He says he first heard about the technique when his Brazilian friends swore by its results. Five years ago, he went back to his native Brazil and spent a day watching a stylist do it. “It took me a little time to learn it,” he says. “I tried it on a few friends and got the hang of it.” His clients now include models—who regularly damage their hair with styling chemicals and constant drying and heating, but who don’t want to lose any length off their locks—as well as women who get regular bleaching, relaxing or straightening treatments, which strips hair of its natural shine and leaves ends damaged and straw-like.

Gomes says he has perfected an after-treatment, which involves a deep conditioning regimen that he won’t reveal, but that he says takes advantage of the hair’s “open cuticle.” “When you run the flame through the hair, it’s such a shock treatment that you need something really strong and powerful to close that cuticle back, and start the growing process to become a lot stronger than what it was,” he says.

Post-conditioning, he goes over the hair again with a pair of scissors, snipping off the singed ends and any rogue flyaways for the smooth, finished look that his clients desire.

The hype: Proponents claim the heat from the candle opens the hair shaft to make it more receptive to conditioning afterward, and burning the ends seals off the annoying split ones. Just as cauterizing a wound stops bleeding, they claim that lighting up hair makes it smoother-looking. Models Alessandra Ambrosia and Barbara Fialho recently posted photos of their precious locks going up in smoke.

The research: But does it really work? Unsurprisingly, there isn’t much research on the practice, but dermatologists specializing in hair care aren’t convinced it’s the best way to smooth out your tresses. “The best way to treat split ends is to get regular hair cuts,” says Dr. Melissa Piliang from the Cleveland Clinic. “Even small trims, called dusting, every six to eight weeks can make hair grow longer, stay healthier and fuller. It’s a much better option than putting fire near your hair, which is flammable, and seems dangerous.”

And exposing hair to more heat, she says, isn’t a good idea. Hot curling irons, straightening irons and high-heat blow-drying aren’t recommended, so the heat from an open flame, however, brief, can’t be beneficial either, they say. Instead, she recommends gentle hair care to keep hair healthy, like using a deep conditioner a few times a week and avoiding hair treatments that strip hair and leave it damaged, such as bleaching and straightening.

Piliang also notes that healthy, shiny hair starts from under the skin, so factors like a healthy diet diet and getting enough sleep can also help. Vitamins like zinc, vitamin D, and iron are critical for making hair grow, and omega 3 fatty acids, found in fish like salmon, contribute to healthy, shiny locks. But it takes a few months of taking these supplements or eating well and sleeping enough to see the results, she says.

The bottom line: Searing off damaged ends may seem like a quick and satisfying way to subdue flyaway hair. But besides doing it all for questionable benefit, you’ll have to sit through what many of Gomes’s clients say they fear is the worst part: several three-hour sessions of smelling your hair lit on fire.

TIME Cancer

Why Breast-Cancer Survivors Gain More Weight

Tumors and treatment may make it easier to put on pounds, and the latest research shows why breast cancer patients should be aware of the dangers of gaining too much

Studies have hinted that breast cancer survivors tend to gain weight after their diagnosis and treatment, but it’s not yet clear why. Because breast cancer rates tend to rise around menopause, doctors weren’t sure whether the weight gain was part of normal aging and changes in women’s reproductive status, or whether something about cancer made patients more vulnerable to gaining weight.

In a new study published in Cancer Epidemiology, Biomarkers & Prevention, researchers compared a group of women who survived breast cancer with a similar group of women who did not have the disease. All women were at higher risk of developing breast cancer because of family history. The scientists found that even after they adjusted for the influence of age, menopause and other factors, those who survived breast cancer did indeed gain more weight—almost four pounds more, on average, within five years of their diagnosis compared to those who didn’t have cancer. Among these women, those who were treated with chemotherapy were twice as likely to gain weight—about 11 pounds more, on average—compared to women who were treated with hormone-based therapies (who did not get any heavier with their treatments) and women who didn’t have cancer.

MORE: New Genetic Test for Breast Cancer Would Be Cheaper and Easier

While weight has been implicated in possibly playing some role in certain cancers, this study is among the first to tease apart what effect cancer itself, and treatments for cancer, might have on changing metabolism, inflammation, the immune system and other body functions to make weight gain more likely. By following the women for four years, the researchers, led by Dr. Kala Visvanathan, director of clinical cancer genetics and prevention service at the Johns Hopkins Kimmel Cancer Center, compared their weight changes from diagnosis onward. The team is planning to continue to follow the women for a longer period of time to track other patterns in weight.

“Obviously treatment [for the cancer] is a priority,” says Visvanathan. “But these findings show that it’s also important to take note of weight changes, especially for women getting chemotherapy. Chemotherapy treatment usually goes for six months or a year, so monitoring weight in that time and taking steps to intervene if weight is clearly increasing is important.”

MORE: Breast Cancer May Increase 50% By 2030

Many cancer patients become less active during chemotherapy, and for good reason—the regimen can be punishing on the body, leaving people feeling fatigued and less energetic. But maintaining a healthy diet and staying physically active, says Visvanathan, are critical to keeping weight down. Weight may play a role in how people respond to cancer treatments, as well as their recovery, so it makes sense to for cancer survivors to try not to gain too much.

In addition, getting heavier is associated with a higher risk of other chronic diseases. And the fact that more cancer patients—particularly breast cancer patients—survive their disease is another important reason to keep weight in check. “Most breast cancer survivors will survive their cancer for years or even decades, and die of other diseases,” says Amy Gross, a PhD candidate in the department of epidemiology at the Johns Hopkins Bloomberg School of Public Health, and a co-author of the paper. “Our study highlights the need to be aware of the impact of weight gain on the risk for other diseases. It’s a problem we need to pay more attention to, in addition to just helping patients survive the cancer.”

TIME Heart Disease

New Advice on Statins Is Leading to Less Heart Disease

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A recent shift in how doctors figure out heart disease risk may lead to 63,000 fewer heart-related health problems, a new study shows

In 2013, when the American Heart Association and the American College of Cardiology revised the guidelines that doctors use to decide which patients need cholesterol-lowering treatment for heart disease and which do not, there was more confusion than confidence in the new advice. Now, a new study published in JAMA may offer some answers about the effects of the updated treatment guidelines.

Rather than setting threshold levels of target cholesterol levels that were considered normal or high, for example, the new guidelines instead assessed a person’s overall risk of having a heart attack, stroke or other heart problem over the next 10 years. If these factors—which included cholesterol, family history of heart disease, age and other factors—contributed to a risk of 7.5% or higher, then the person would be eligible for taking the cholesterol-lowering drugs known as statins, which not only bring potentially troublesome fat levels in the blood down but also reduce inflammation, which can contribute to atherosclerosis and set the stage for a heart attack.

MORE: Should I Take a Statin? What You Need to Know About the New Cholesterol Guidelines

Heart experts weren’t all convinced that putting more people on statins would actually lead to fewer heart events. Their biggest concern was that the looser criteria would mean more otherwise healthy people who wouldn’t really benefit from statins would be taking the drugs. (Some estimates showed that as many as 12.8 million more people would be taking the medications under the new guidelines.). So Dr. Udo Hoffman, director of the cardiac MR, PET and CT Program at Massachusetts General Hospital and his colleagues decided to analyze the data to see if the new guidelines really were contributing to less heart disease.

In the new study, they compared 2,435 people who were the offspring or third generation descendants of the Framingham Heart Study, the pioneering heart disease trial that continues to follow people and track their lifestyle and health outcomes. Some of the participants in the current study were at higher risk of heart disease, and some were not. Using the older cholesterol-based heart risk guidelines, Hoffman found that 14% would have been given a statin. Nearly three times that proportion, 39%, would have qualified under the new 2013 guidelines.

MORE: New Guidelines for Cholesterol Treatments Represent “Huge Change”

When the researchers looked at how many of those people who were eligible to take statins went on to have heart events, it was more than twice as high using the newer guidelines. That means that a higher proportion of people who should be on statins, according to the newer guidelines, went on to have heart events, suggesting that the new criteria were better at predicting which people were at higher risk.

In addition, Hoffman also backed up his findings with tests of the amount of calcium in the heart vessels of the participants. Coronary artery calcium tends to be a good indicator of how stiff the vessels are becoming; more calcium suggests more atherosclerosis and therefore a higher risk of heart attack or other issues.

MORE: Statins May Seriously Increase Diabetes Risk

The findings were especially robust in those people considered to be at intermediate risk of heart disease—patients in the grey area where it’s not entirely clear how likely they are to have heart problems. Among them, those who qualified to take statins under the newer 2013 guidelines were nine times more likely to have a heart event than those who didn’t meet the criteria for needing the drugs. “If we looked at this group from the formal risk factor evaluation approach [using the older guidelines] there is no way we could guess which of these people were at higher risk of heart events,” says Hoffman. “So in this population, the new guidelines are helpful.”

The findings show that even if the revised guidelines cast a wider net of people who would be on statin drugs, the rate of heart events the new criteria are picking up remain about the same. That means that the people being captured are still those at higher risk of having events, and not healthy people who would be unnecessarily put on medications, as some critics of the new guidelines feared. “Overall, the new guidelines are a more accurate and efficient allocation of statin therapy,” says Hoffman.

TIME global health

Here’s How Much More Money Is Needed to Improve Global Health

Outbreaks like Ebola highlight the gaps in the way money is raised and used for protecting people’s health, a new study finds

In a report published in the journal Lancet, researchers point out large gaps in the money raised and dispatched for public health purposes and the medical needs of countries, particularly in the developing world, to keep their populations healthy.

Despite recurrent outbreaks of pandemic infections such as SARS and, most recently, Ebola, donors have committed less than a third of the estimated $3.4 billion that is needed to maintain a strong pandemic preparedness system, according to the World Bank. Overall, donor countries have spent only half of the $6 billion that the World Health Organization says is needed to maintain global public health.

What’s lacking, the study authors say, is a more focused system for investing in global health that emphasizes programs designed to achieve certain public health functions, such as vaccinating a particular population or corralling antibiotic resistance or the spread of multi-drug resistant tuberculosis. It’s an approach championed by philanthropic organizations such as the Bill & Melinda Gates Foundation, the organization that funded the study. Part of the funding conditions of its programs include specifying outcomes and a timeframe for achieving them.

“For example, countries like China and India would substantially benefit from market shaping to lower drug prices and increased international efforts to control multi-drug resistant tuberculosis,” Dr. Marco Schaferhoff, association director of SEEK Development in Germany and one of the co-authors of the report, said in a statement. “At the same time…donor countries should also ensure that vulnerable and marginalized populations in middle-income countries, such as ethnic minorities who suffer discrimination, refugees, and people who inject drugs, receive sufficient support.”

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