TIME Infectious Disease

Ebola Treatment May Emerge From Drug For Another Virus

Ebola and Marburg belong to the filovirus family, and encouraging results from a gene-based therapy against Marburg could jump-start a similar treatment for Ebola

With the latest outbreak of Ebola in western African claiming more than 1,200 lives since March, any advances on the treatment front are welcome—even if they come from studies of a related virus.

Thomas Geisbert, professor of microbiology and immunology at the University of Texas Medical Branch at Galveston, is getting more attention than he expected for his work on a promising therapy for a virus called Marburg because of its potential application against Ebola. In the journal Science Translational Medicine, Geisbert, who spent two decades at the U.S. Army Medical Research Institute of Infectious Diseases working on treatments for emerging and lethal pathogens, reports that delivering bits of RNA encased in a protein to monkeys infected with the nastiest Marburg strain can save their lives. While all of the 16 animals treated with the experimental treatment survived, none of the animals who weren’t treated did.

MORE: We’re Getting Closer to Vaccines and Drugs for Ebola

In 2010, he and his colleagues published equally promising results using the same technique against Ebola Zaire, the same strain responsible for the deaths in western Africa. In that study, however, the animals were treated within an hour of being infected with a highly lethal dose. The animals survived, so Geisbert is eager to test whether delaying treatment longer, up to several days after infection, will also protect patients, just as it did with the monkeys in the current study. Having such a window is critical because in reality, people may not even know they have been infected until they experience symptoms like fever or headaches.

“This is the first study showing that we can treat [filovirus infections] when we first start seeing signs of illness,” he says. “I am very confident that the same will hold true with Ebola. We demonstrated in 2010 that the same strategy works against Ebola Zaire and I think we certainly can optimize the strategy to perhaps do even better.” The animals in the study were dosed with a much higher amount of virus than people would generally see, so Geisbert believes that if it’s possible to extend protection against Ebola, it would buy up to a week of time in which people could be successfully treated. What’s making Geisbert so optimistic is the fact that the technique involves blocking the virus’ ability to reproduce, unlike the therapy that two American health workers received, which relies on antibodies that stick to the virus and incapacitate it before it can infect healthy cells.

MORE: Containing Ebola Is Extremely Labor Intensive, Former CDC Researcher Says

Tekmira, a Canadian biotech company, has begun early human trials testing the safety of the Ebola version of the therapy. While the Food and Drug Administration requires human trials for all new drugs and vaccines, for so-called exotic viruses like Ebola and Marburg, for which intentionally infecting volunteers wouldn’t be ethical because of their lethality, the agency makes an exception. It accepts tests involving animals that replicate the human course of disease, and a trial of the drug’s safety in uninfected, healthy human volunteers. The FDA had put a hold on the company’s application for approval, pending more confirmation that the product was safe to study in healthy people in escalating doses, but that in August the agency changed that to a partial hold. That makes it possible for any person, or country, that requests the treatment to receive it under emergency conditions.

“There is a lot of pressure to move studies [on Ebola] to the forefront and do them sooner rather than later,” says Geisbert. And now there’s more evidence that doing so could potentially save more lives.

MORE: Inside the CDC’s Emergency Operations Center Tackling Ebola

 

TIME Exercise/Fitness

Exercise Makes Kids’ Brains More Efficient

Brain
Science Photo Library/Corbis

For the first time, there’s evidence that being fit can improve the speed and connectivity of brain neurons in children

There’s plenty of evidence that suggests that children who are more physically active do better in school. But what’s contributing to the boost in brain power?

In a study, published in the journal Frontiers in Human Neuroscience, researchers led by Laura Chaddock-Heyman, a research associate in psychology at the University of Illinois at Urbana-Champaign, report that children who are more fit have more white matter in their brains than those who aren’t as fit. The areas of the brain where more white matter was observed are important for attention and memory, and are critical for linking different parts of the brain together.

The study is the first to find a connection between exercise and white matter in children. Previous studies focused on specific structures of the brain, such as the hippocampus, which is involved in memory, and how exercise affected their size and volume. In the current study, however, Chaddock-Heyman and her colleagues show that the improved fitness that comes with exercise may lead to other beneficial changes in the brain as well, such as improving the way signals are sent around the brain via the white matter.

But whether the bulkier white matter actually translates into higher IQ or better school grades isn’t clear yet. Chaddock-Heyman says the study did not track the students’ cognitive abilities, though previous, smaller studies have linked white matter to better math scores, for example. “It’s possible that white matter differences as a function of fitness are driving the cognitive differences we see in the brain,” she says. “But that that’s speculation at this point.”

What the results do show, however, is that physical activity may be an important part of keeping children’s brains active and open to learning. Physical education class and recess may be just as important to doing well in school as time spent in a classroom. “We are hoping our work encourages more support of physically active lifestyles,” says Chaddock-Heyman. She and her colleagues are continuing their work with a five year trial in which children are randomly assigned to an aerobic fitness program or not, so their white matter changes and their academic performance can be tracked.

“More schools are contributing to our more sedentary lifestyle by eliminating or reducing physical activity during the school day,” says Chaddock-Heyman, “and we know that aerobic fitness is related to the size of brain structures as well as their function.”

TIME Nutrition

Eggless Eggs Exist and This Is What They Taste Like

Hampton Creek

No it’s not science fiction.

The product’s logo says it all. It’s a silhouette of a tiny plant against the background of an egg shell, and it represents a revolutionary idea in food, questioning the land-laden, energy-heavy and labor-intensive way we grow so much of what we eat. It also represents the first time a company has created—and gotten to market—a food that acts like an egg and tastes like an egg, but comes from a Canadian yellow pea, not chickens.

Hampton Creek Foods launched its eggless mayonnaise just over eight months ago and its flagship product, Just Mayo, is already the leading mayo brand at Whole Foods Markets. In September, it will take over Walmart and Target shelves too and based on the growing interest in its products so far, the company expects to earn $35 million in sales this year.

During a recent visit to Hampton Creeks’ research facilities in San Francisco, in a warehouse between the city’s SOMA and Mission neighborhoods, I found the cramped space was a hub of activity. It was here that founder and CEO Josh Tetrick began his journey two and a half years ago to find a new way to make food—starting with the egg. With the help of biochemists, food scientists, data scientists and chefs, he is rethinking where our food comes from and how it’s grown. It’s not about replacing what we currently have, he says, but about making it better – more nutritious, and cheaper by about 30%.

Tasting the Eggless Eggs

On the day I’m there, dozens of people—from biochemists to data scientists to chefs—were busy fulfilling the next stages of the company’s mission. Tetrick says the company has already piloted eggless raw cookie dough as well as a liquid egg-like substance that can be used on French toast or even scrambled on their own. Now, they’re trying to cull from the world of plant proteins to develop alternatives to sugar or even fat.

So how does it taste? The mayo is indistinguishable from regular mayo. So much so that celebrity chef Andrew Zimmern is a fan: in a blind taste test, he preferred the richness of Just Mayo to Hellmann’s. The cookies are moist and crumbly, and even the raw cookie dough pretty faithfully replicates the taste of a traditional batter—but without, as Tetrick points out, the risk of salmonella poisoning or the burden on the environment that comes with raising hundreds of thousands of poultry.

That’s why companies like Walmart, Target, Kroger, Safeway, Ralph’s, Shoprite and Costco are signing deals to carry the company’s mayonnaise. From the beginning, Tetrick says, Just Mayo was not meant to be a boutique brand aimed at the 1% who can afford to worry about the environment. Case in point: Just Mayo will also be at the Dollar Tree. That every-man mentality, which means the eggless egg could also help to alleviate hunger around the world as an important and cheaper form of protein, has also attracted some of the company’s biggest-name investors, including Bill Gates, Yahoo co-founder Jerry Yang, financier Tom Steyers and Chinese entrepreneur Li Ka-Shing.

The Scrambled Challenge

But before that can happen, Hampton Creek’s chefs and chemists are trying to tackle their biggest challenge yet — scrambled eggs. For the 30% of products like muffins, cookies and mayo in which eggs are just an ingredient and not the star of the show, their product has exceeded expectations. But when it comes to throwing the yellow-pea “egg” into a pan…that’s been a challenge that’s stumped — and continues to stump — the team. To move things along, Tetrick recently hired Trevor Niekowal from Chicago’s trendy Moto restaurant, and Niekowal is eager to show me the latest version of their scramble-ready egg. He starts by whipping up some French toast using Wonder bread. It tastes indistinguishable from the real thing, with the right crispiness that comes from a sautéed-egg coating.

He admits, though, that heating the product on its own is still a work in progress. Back in April, the culinary team, which includes other Moto alums Chris Jones, a former Top Chef contestant and pastry chef Ben Roche, eagerly poured the product into the pan, only to watch the liquid evaporate into nothing. The next version, beefed up with stronger chemical bonds, stayed together a little too well, forming a flat crepe that didn’t have any of the fluffiness of an egg.

For my taste test, Niekowal pours some of the egg mixture into a skillet and it looks no different than something cracked out of a shell and whipped into a slightly runny yellow liquid. It hits the pan with a slight sizzle and stays a little runny before fluffing up and rolling once it’s been heated. The taste, however, still needs some work. The eggless eggs I ate at Hampton Creek tasted like, well, tofu. ‘We’ll tell that to our food scientists,” says Niekowal.

The Sky’s the Limit

And they’ll likely get it just right eventually. In fact, Tetrick is so confident of that that he’s looking even beyond the eggless egg and making even bigger plans to re-make food. He recently hired Dan Zigmond, responsible for managing data for Google Maps and YouTube, to make the company’s plant-based database even more nimble and productive. “We built this company around the idea that there are 400,000 plant species in the world,” says Tetrick. “Remarkably, 92% of them haven’t been explored for how to make food.”

And so Tetrick and his team are painstakingly annotating as much of that database as possible, with valuable information such as the proteins’ weight, their molecular properties—does it form gels? what happens when it’s heated?—and where they are grown. In order to qualify for Hampton Creek consideration, the plant can’t be a premium crop or one that requires excessive or unusual conditions to grow. That wouldn’t help to make the food a less expensive option than what we currently eat. “For the first year and a half of the company, there was a lot of grinding out information about the proteins, lots of trial and error before we started seeing things,” says Tetrick.

But the database is starting to bear fruit — the team is perfecting a super-food high in protein that could potentially address malnutrition in developing nations, as well as looking for healthier ways to sweeten foods. “The world is so addicted to soy and corn, it’s almost like we forgot about the abundance and complexity of the natural world,” he adds. “I think that’s unfortunate.” There’s a big world of plant proteins out there just waiting to be mined for taste, nutrition and health benefits. And for now at least, there’s always the eggless egg.

TIME Sex

Don’t Be Afraid of Housework, Guys. It Won’t Lead to Less Sex

That’s what the latest research shows, calling into question earlier work that suggested that more equal roles in the home contributed to less fun in bed

Housework can be a downer, but when husbands pitch in to cook, clean and keep the abode tidy, it could also put a damper on their sex lives. So said researchers from the University of Washington in 2013. If husbands left the meals and toilet cleaning to their wives, they had sex nearly twice as much as husbands who performed these chores.

But Daniel Carlson, an assistant professor of sociology at Georgia State University, and his colleagues say that study used data from the 1980s and 1990s, before more egalitarian roles in both in and outside of the home became the norm. Plus, other work suggested the opposite, and hinted that women often used sex as a reward for their husbands who performed chores, leading to more sex among men who picked up the laundry detergent. So he and his team looked at more recent data involving 487 couples enrolled in the 2006 Marital and Relationship Survey to see if housework continued to have a chilling effect on sex.

To a certain extent, it did. Among couples where men shouldered most of the daily household chores, the sex was less frequent and less satisfactory, just as the 2013 study found. But in Carlson’s study, couples who shared housework more equally also reported having a healthy and happy sex life, as did couples in which women di most of the cooking and cleaning. “Where previous research said egalitarianism was the problem, and that couples with a more traditional division of labor seemed to be doing better, our study shows that egalitarian couples have in some respects caught up,” says Carlson. “Both [groups] are leading sex lives that are satisfying.”

The reason, he says, may have to do with the broader effect that sharing responsibilities have on a relationship. Couples who feel they are sharing the duties of raising a family and managing a household are more likely to be happy in their relationship, and that leads to more affection.

MORE: Chore Wars: How the Division of Domestic Duties Really Affects a Couple’s Sex Life

The results, which were presented at the annual meeting of the American Sociological Association, won’t likely be the last word on understanding how gender roles within relationships affect sexual attraction, not to mention the strength of the bond between couples. But the research does hint that as evolved as we like to think we are about how equal men and women are when it comes to raising a family and running a household, we still have a ways to go before doing the dishes and scrubbing toilets are truly gender-blind tasks.

While more couples are accepting of situations when the husband and wife share in these duties, among couples in which the husband is bearing most of the burden of managing the home, social and cultural hurdles still exist. “When couples end up in an arrangement where the male is doing the majority of the housework, it’s not something that the couples tend to choose,” says Carlson. “They end up in the arrangements due to unforeseen circumstances such as the male partner losing his job, or the female getting a big raise that makes her the primary bread winner.” While these couples are relatively rare, making up only 5% of the study population, they may represent the final barrier to making housework not just a woman’s job.

MORE: Why Husbands Who Share Household Chores Miss Out on Sex

TIME Health Care

Your Next Blood Test Could Cost $10,000

That’s how much one Cal. hospital charges for a routine cholesterol test. Others charged as little as $10 for the exact same assay

We’re used to comparison shopping, and we know where we can get a better deal on the exact same box of cereal or the same pair of sneakers. But when it comes to the routine blood test you get every time you see the doctor, how budget-conscious can you be?

Not very, new research shows. In an eye-opening report published in the journal BMJ Open, Dr. Renee Hsia, an associate professor of emergency medicine at the University of California, San Francisco, and her colleagues found that cholesterol panel could cost patients anywhere from $10 to $10,169 — a more than thousand-fold difference. A basic metabolic test for things like blood sugar ranged from $35 to $7,303.

“I was expecting a little variation, maybe two-fold, or even three-fold,” says Hsia, who also studied differences in total costs for procedures like having the appendix or tonsils removed. “But I wasn’t expecting this amount.”

She focused specifically on blood tests because they are automated and not prone to variations in the quality of the technician or other bells and whistles required to spit out results. “It should be like buying a loaf of bread,” she says, with only slight differences in price.

MORE: An End to Medical-Billing Secrecy?

But the thousand-fold range shows just how seemingly random health care pricing can be. “There is probably nothing justifiable [for the high cost] in this case,” she says. Even if the most talented technician were performing the lipid analysis using the most sophisticated machine, it’s hard to imagine those services requiring $10,000 worth of equipment or labor.

And it’s not as if individual hospitals are guilty of overcharging consistently. One hospital may have high fees for one test and lower fees for others. In Hsia’s study of 150 California hospitals, the one that charged more than $10,000 for the cholesterol test was not the same one that billed more than $7,000 for a metabolic test. Factoring in things such as whether the hospital was for- or not-for-profit, whether it was a teaching hospital, and the percentage of patients covered by Medicaid still didn’t explain the gap in pricing.

MORE: Bitter Pill: Why Medical Bills Are Killing Us

Master lists at each hospital set these fees, she says, and in recent years, some hospital administrators have admitted that even quantitative factors such as supply, demand or overhead costs don’t factor into these prices. In 2013, Secretary of Health and Human Services Kathleen Sebelius released the prices of 100 of the most common inpatient services at hospitals across the country in an effort to make the process more transparent.

And if you think you won’t have to worry about these prices because you’re insured, you may be feeling these costs the next time your premium creeps up. While private insurers negotiate with hospitals to accept certain fees, that rate is a percentage of the original charge — the higher the charge, the higher that negotiated fee will be. And insurers pass on those costs to their members.

So can a financially responsible patient comparison shop for hospitals with the most reasonable fees? Not really.

California law mandates that hospital report what they charge for any 25 of the most common outpatient tests. But they don’t specify what those tests are, and hospitals can chose which ones they provide to the public. The entire list of fees is also available, but not as easy to navigate for patients who aren’t familiar with the codes for the tests. “It’s not that transparent, and hard for patients to access the information,” says Hsia.

“When people hear about price variation, they say it’s probably just one hospital, or one blood test or one procedure, and they think it’s the exception rather than the rule,” says Hsia. But evidence is mounting that’s not the case. “It’s not a hospital issue, it’s a fundamental problem because there is not a rational way to determine hospital pricing, and that needs to be addressed.”

 

TIME Cancer

How Aspirin Can Prevent Breast Cancer

Among overweight and obese women, the painkiller could help to prevent tumors from recurring

Doctors are beginning to learn that body weight could have a role in determining a woman’s risk for breast cancer as well as her ability to survive it — and according to new research, a surprisingly simple over-the-counter drug could help with prevention.

“Obesity by itself is the worst prognostic factor,” says Linda deGraffenried, an associate professor of nutritional sciences at the University of Texas at Austin. “Obese women do worse on hormone therapy, chemotherapy and radiation therapy. We used to think that the mechanism involved the fact that they had [other] conditions such as diabetes or heart disease, but now we are starting to appreciate that the obese patient has a different biological disease.”

And that understanding led deGraffenried and her colleagues to the surprising finding that among women with a higher body mass index (BMI), nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin can actually lower their risk of breast cancer.

In a report published Friday in the journal Cancer Research, deGraffenried found that obese and overweight breast cancer patients who used NSAIDs regularly lowered their risk of getting additional tumors by 52% compared with women who didn’t take the pills. “I’ve been doing cancer research for 20 years, and there has been nothing that was able to give that kind of benefit,” says deGraffenried. “So yes, I was extremely surprised that by just reducing inflammation you could get that significant a benefit.”

What’s happening in obese patients, she says, is that their larger volume of fat tissue promotes production of aromatase, an enzyme involved in producing a form of estrogen called estradiol. Because estrogen is part of the fuel that drives breast-cancer growth, having elevated levels of aromatase is associated with higher rates of breast cancer. The mechanism also explains why drugs that inhibit the enzyme aren’t as effective in obese or overweight women. The fat tissue also promotes release of other factors that are important for tumor survival, creating a feedback loop that keeps the cancer growing in heavier women.

But NSAIDs, which block another enzyme that stimulates aromatase production, could counter this effect. And that’s what deGraffenried and her colleagues found. Among a group of 440 women diagnosed with breast-cancer tumors containing estrogen receptors, those with a BMI greater than 30 and who used NSAIDs regularly had a much lower rate of breast cancer.

Whether women with other types of breast cancer, including tumors without estrogen receptors, can benefit from NSAIDs isn’t clear, but the team is studying those populations as well.

As for whether an aspirin a day should become part of women’s breast-cancer prevention efforts, deGraffenried notes that many already take low-dose aspirin — the same does that most of the women in the study took — to protect against heart disease and colon cancer. “If you are not already on an NSAID or if there is no contraindication for an NSAID, there is reason to consider asking your doctor about it,” she says.

MORE: Osteoporosis Drugs Do Not Prevent Breast Cancer After All

MORE: Breast-Cancer Drug Has a Surprising New Application, Study Finds

TIME medicine

Growth Hormone Linked to Higher Risk of Stroke

Children treated with growth hormone are more likely to experience strokes decades later

Since the Food and Drug Administration approved a synthetic form of growth hormone (GH) in 2003 to treat short stature in kids, it’s become a popular medication not just among parents who want their children to grow but also in locker rooms of professional athletes who believe the collagen-building features of the drug can both protect and improve recovery from injury.

Now the latest study shows that children treated with GH are at risk of bleeding in the brain nearly 20 years later. French researchers report Wednesday in the journal Neurology that among a group of children treated for short stature or low levels of growth hormone had between a 1.5 to 5.3 times higher risk of having a stroke during the follow-up period than the general population.

“Subjects on or previously treated with growth hormones should not panic on reading these results,” the authors said in a written statement. “The results of this study highlight the importance of studies of this kind for the evaluation of the long-term effects of treatment.”

While the researchers can’t explain why the hormone treatments, which are usually given in daily injections over four to five years, led to the strokes, earlier studies on animals with a metabolic disorder in which they produced excessive amounts of the hormone showed that they tend to have more bleeding events. The scientists admit, however, that it’s also possible that short stature itself may have some connection to stroke risk since other disorders in which people don’t grow properly are also linked to abnormal blood flow to the brain.

The study, which involved nearly 7,000 participants, provides good reason for people taking growth hormone to discuss the potential risk of stroke with their doctors, say the authors. Whether the findings apply to others who take growth hormone – athletes who use it for performance enhancement, or those affected by other diseases such as kidney disorders – isn’t clear yet.

TIME Cancer

Treating Cancer With Bacteria Shows Real Promise

Pipetting sample into multi well tray
Rafe Swan—Getty Images

In a groundbreaking study, researchers say injecting bacteria into a tumor helped shrink it

Bacteria are generally considered more foe than friend, but that may change, if results from a pioneering study are confirmed.

Reporting in the journal Science Translational Medicine, scientists led by Dr. Saurabh Saha, a cancer researcher at biotech company BioMed Valley Discoveries, found that directly injecting Clostridium novyi, a common bacteria species that doesn’t need oxygen to survive, into tumors in both dogs and a single human patient shrunk or eliminated tumors and possibly bolstered the immune system to continue targeting tumor cells for up to two years.

“We don’t use the word cure often in cancer. We need to remain humble,” says Saha. “But when we started treating the dogs, we achieved cures. That gets you really excited.”

The fact that bacteria could potentially be a valuable ally in fighting cancer first emerged more than a century ago, when William Coley, a bone surgeon, observed that some cancer patients who developed severe bacterial infections also experienced remission of their cancer. Coley began using Streptococcus pyogenes to treat cancer, but wasn’t able to generate a consistent enough response. The bacteria also produced more toxic reactions than antitumor responses.

But in recent decades, researchers at Johns Hopkins led by Dr. Bert Vogelstein, director of the Ludwig Center for Cancer Genetics and Therapeutics, revisited the idea, combing through databases of bacteria for just the right combination of features that included thriving in low-oxygen conditions while producing few adverse reactions from infection such as fever and inflammation.

C. novyi, when stripped of its primary toxin-producing gene, seemed to fit the bill. First in mouse studies, then in trials involving dogs, the bacteria was a precise and effective tool for eliminating tumors. Saha trained under Vogelstein and was galvanized by the promising data. Because it grows best under oxygen-starved conditions, C. novyi targets just the stubborn cancer cells that are hardest for current anticancer treatments to reach.

Among a group of 16 dogs who had soft-tissue sarcomas, six responded to the bacterial treatment. The pets received anywhere from one to four cycles of 1 billion spores each. In three of the animals, the tumors completely disappeared and the animals remain cancer-free nearly two years later. In three others, the growths shrank by at least 30% after 21 days.

That success encouraged the team to consider testing in humans, and the first patient to try therapy in an early trial enjoyed similar results. A 53-year-old woman with a rare cancer that had spread to her liver, lungs, shoulder and leg bones agreed to get an injection of the C. novyi preparation, albeit at a much lower dose than the dogs. Around 10,000 spores were injected directly into a tumor in her right shoulder. She developed an abscess when her immune system tried to battle the bacteria, but after four days, an MRI of the growth showed it had dramatically shrunk. Nearly a month later, the tumor continued to get smaller.

It turns out the bacteria are almost the perfect cancer-fighting weapon, able to target stubborn tumor cells and microscopically destroy just the malignant cells while leaving normal tissue alone. “When the spores reach the [low-oxygen] regions, they germinate and start growing, producing substances and enzymes that are toxic to tumor cells and cause their destruction,” says Nicholas Roberts, a co-author of the paper and a postdoctoral fellow at the Johns Hopkins Sidney Kimmel Comprehensive Cancer Center.

When they reach the edges of the tumor, says Saha, the bacteria stop their destructive activity. “Once they see the well-oxygenated rim of the tumor, they self-eliminate and can’t grow anymore. They are almost like a surgical, biological scalpel. Surgeons can’t get to that level of precision in terms of cutting out a tumor.”

Saha, whose biotech company is working on further testing of the approach in human patients, hopes that it will become part of the cancer-fighting arsenal in coming years and believes bacteria, used in combination with other immune-based approaches or even chemotherapy or radiation, could help to improve cancer outcomes. Unlike the latest targeted drugs that hone in on specific genetic mutations in cancer cells, the bacteria can be effective against any solid tumor that has a low-oxygen region, regardless of whatever genetic mutation caused it grow out of control.

If the results hold up, the strategy would be among the first in which a bacterial infection is a welcome thing. “There is a lot of hope in moving forward with this,” says Roberts.

MORE: There’s a Vaccine Against Cancer, but People Aren’t Using It

MORE: On the Horizon at Last, Cancer Drugs that Harness the Body’s Own Immune System

TIME Exercise

More Exercise Isn’t Always Better, Study Shows

Men and women run on treadmills at a fitness gym in the West Bank city of Ramallah on June 25, 2012.
Men and women run on treadmills at a fitness gym in the West Bank city of Ramallah on June 25, 2012. Abbas Momani—AFP/Getty Images

The latest research shows there may be an upper limit to how helpful exercise can be on your heart

It’s probably not news to you that Americans just don’t exercise enough. Less than half of us meet the recommended amount of weekly physical activity—despite research that shows exercise can be just as effective as drugs in some cases to treat diseases such as diabetes. So why don’t we prescribe exercise in specific doses, like we would a drug?

In order to do that, you need to know exactly how much activity produces how much benefit, and whether there’s an upper limit, at which point the helpful effects either start waning or begin to do more harm than good. That’s what Paul Williams, a staff scientist at Lawrence Berkeley national Laboratory, and his colleagues wanted to know—and they found out in a new report published in Mayo Clinic Proceedings.

MORE: Short Bursts of Exercise Are Better Than Exercising Nonstop

Williams started with a group of heart-attack survivors who had been enrolled in either the National Runners’ Health Study or the national Walkers’ Health Study. The two studies were designed to measure what impact—measured in deaths due to heart disease—differing amounts of physical activity could have. “The notion that there was increased risk for people at high exercise has been around for a while, but the first thing that came into my mind was that there was something unusual and maybe something wrong about the data,” Williams says. “So I was hesitant to proceed.”

But as the data continued to emerge, it began to appear that exercise, like any other prescription, could be dangerous in high doses. Those who had had heart attacks and ran more than 30 miles a week or spent more than six hours in vigorous activity weekly were at an increased risk—by up to twofold—of dying from a heart event. “I certainly expected a point of diminishing return, but I wasn’t expecting to see the increase in mortality,” says Williams.

MORE: An Hour of Exercise Can Make Up for a Day of Sitting Down

In contrast, those who exercised moderately—which is to say more than the admittedly low recommended minimum but not as much as the extremely active—lowered their risk of heart-related death by 63% compared to those exercising the least.

“I would say the gains of being active are substantial,” says Williams, “but up to a certain point.” The results held after his team adjusted for the potential effects of age, diet and medication.

MORE: Exercise Snacking: How to Make 1 Minute of Exercise Work Like 30 Minutes

Williams stresses that the results only apply to a relatively small group—people who have a history of heart disease and who exercise at high levels—but he’s currently studying the same thing in the general population to see if similar trends are at work. The data could form the foundation for a prescription-based approach to exercise, as researchers become more familiar with how much exercise can influence factors that affect our health. For now, says Williams, “The message is that at least for heart attack survivors, more is better—up to a point.”

TIME Mental Illness

Why We Aren’t Better At Preventing Suicide

Robin Williams attending the Broadway Opening Night After Party for 'Bengal Tiger at the Baghdad Zoo' at espace in New York City
Robin Williams attending the Broadway Opening Night After Party for 'Bengal Tiger at the Baghdad Zoo' at espace in New York City Walter McBride—Corbis

Robin Williams' tragic death re-ignites long-asked questions about why it’s so challenging to identify and help those at highest risk of self-harm

Robin Williams’ death has served as a stark reminder that we have a long way to go in helping people at serious risk for self-harm. Part of the challenge, say experts, is that despite their stigma, suicidal thoughts are quite common, particularly among people who are depressed. “Suicidal thinking is common and widespread, especially among people with mental illnesses,” says Dr. Dost Ongur, chief of psychotic disorders at McLean Hospital and a psychiatrist at Harvard Medical School. “Yet we don’t have good ways of deciding who is at genuine risk, and who is suffering but who won’t go through with hurting themselves. The reality is that there is no established way of saying this person is at higher risk than that person.”

It’s not that anyone is expecting that a simple blood test or brain scan will provide the answer; the machinations of the body and mind are too complex for that. But as researchers learn more about the brain processes that lay the foundation for things like depression or addiction, they are moving toward developing a suite of tools that could help to at least triage people who are most vulnerable to harming themselves. “It’s something that comes over people; it can last hours or days, but not forever. If you can keep somebody safe during that period, it would pass,” Ongur adds. “The depression would remain, and the substance abuse would remain, but the intense feeling of not being able to go on would pass.”

MORE: Suicide in America: The People who Answer the Phone

Identifying people who might be especially vulnerable to those episodes could be a first step in preventing suicide attempts. In July, scientists reported finding that a gene involved in tamping down a stress response is different among those who have tried to end their lives compared to those who had not. The gene is integral to activity in the brain’s prefrontal cortex, which is responsible for things such as impulse control and reining in negative thoughts. It was in short supply in patients who reported suicidal thoughts.

Another group, led by John Mann at Columbia University, is focusing on the brain chemical serotonin, known for its role in mood disorders, and at Harvard, researchers are exploring the use of a bedside test that can probe the brain of patients with mental illnesses for clues to suicidality. All of these strategies, says Ongur, could help to shed more light on the black box that lies at the intersection of thought and action. “We don’t have a good framework for explaining what happens in the moments when a person is preparing to commit suicide.” That provides a window of opportunity for potentially life-saving interventions.

MORE: Robin Williams: The Comic Who Was Hamlet

Mental illness and substance abuse—both of which are correlated with suicide—are treatable, and could be the first step toward shifting patients away from self harm. Strengthening relationships can be another important factor. “The sponsor in AA is an example, a psychotherapist is another example and family relationships are other examples. We live in a relational world and people consider the impact their actions have on people important to you,” Ongur says.

But strengthening such relationships also requires a shift of a different kind, a societal change in how we perceive mental illness and react to those affected. “One of the big issues remains the stigma of mental illness, especially suicide,” says Ongur. “We are still dealing in a very real way with suicide not being something that is talked about openly and commonly. I saw a comment that the best tribute to Robin Williams would be talking more openly about suicide and making it part of a national conversation so that more research can be done and more people can be helped.”

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