TIME Diet/Nutrition

Here’s What Soda Does to Young Rats’ Brains

Soda is on the mind. A new small study in rats found that drinking sugary beverages may result in memory issues down the line.

University of Southern California researchers looked at adult and adolescent rats, and feed them sugary beverages (meant to mimic soda) for a month. After a month, the rats completed tasks that assessed their cognitive function and memory. The adult rats had no problems, but the adolescent rats who had been drinking sugary beverages had impaired memory and trouble learning.

The findings are being presented at the Annual Meeting of the Society for the Study of Ingestive Behavior (SSIB), and are preliminary. The researchers plan to explore whether the soda is causing inflammation in the brain’s hippocampus, which is the region of the brain involved in memory and learning.

Though the research has not been done in humans, it’s part of a growing body of work looking at the risks of soda.

TIME Infectious Disease

Everything You Need to Know About the Deadly Ebola Virus Outbreak

A look at the numbers behind the largest ebola outbreak on record, which has so far killed over 670 people

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More than 670 people have died from the latest outbreak of Ebola, a highly contagious virus that is also one of the deadliest human diseases.

Though it’s been almost 40 years since Ebola was first discovered in 1976, there are currently no cures or effective treatments.

Here’s what you need to know about the unprecedented outbreak.

TIME Cancer

You Asked: Is Sunscreen Safe — and Do I Really Need It Daily?

Is sunscreen bad for me?
Illustration by Peter Oumanski for TIME

Tons of you Google it. Our experts have the answer

Google sunscreen and toxic and see what you find. Claims that titanium dioxide is hazardous? Claims that you need vitamin D, and a little unprotected sun can give you that? Claims that chemical sunscreen can turn boy fish into girl fish? Let’s settle this for once and … for now, at least.

First thing’s first. There are two kinds of sun blockers — the physical kind, like zinc and titanium dioxide, and the chemical kind, like oxybenzone and its many cousins. They work in vastly different ways, the former blocking or “scattering” the sun’s rays (literally), and the latter causing a chemical reaction that is said to prevent damage from the sun’s UVA and UVB rays.

Start looking into it and two topics tend to come up again and again. The first surrounds titanium dioxide or zinc oxide — but only in their nanoparticle form — which means ultra-fine specs of material used in sunscreens to block or “scatter” the sun’s rays. Some scientists have voiced concern that nanoparticles may be small enough to slip past your skin’s defense barriers and into your bloodstream. Those concerns have grown louder since a recent study — albeit in rodents — found that mice injected with titanium dioxide nanoparticles developed inflammation, a marker of cell distress that has been linked to lots of terrible things that happen in the body, including aging — and cancer.

These concerns do not extend to sunscreens that contain titanium dioxide and zinc in non-nano form—although those are becoming harder to find.

The second source of concern involves other nonnano sunscreen chemicals, which work by absorbing the sun’s ultraviolet radiation as opposed to reflecting it. More animal studies have hinted at ways in which some of these chemicals could cause damage to a person’s endocrine — hormone — system. That’s the worrisome news and if you want to avoid risk, many experts contend, you are better off with nonnanoparticle forms of the physical sun blockers.

The good news: there just isn’t much hard data showing that applying these chemical sunscreens to your skin can lead to health problems, says Dr. Henry W. Lim, chairman of the Dermatology Department at Henry Ford Health System in Detroit.

Lim points out that many of the animal studies at the root of sunscreen concerns involve injecting or inhaling the chemicals, not rubbing them on your skin. “As of today there are no recorded health issues associated with sunscreen’s proper use,” he says.

But, in almost the same breath, Lim says there may still be reasons to worry about sunscreen. Specifically, he says spray-on sunscreens could present some unique dangers. That’s because, unlike lotions spread on the skin, spray-ons can be inhaled. “That could lead to very different types of risks not associated with creams,” he says, adding that the FDA is in the process of investigating the potential dangers of spray-on products. (The FDA is also, after much delay and pressure, investigating the introduction of new sunscreen ingredients that have been on the market in Europe for some time. Stay tuned for more on the bill that could change that.)

Looking past the possible dangers of sunscreen use, the benefits are far less nebulous: 1 in 3 cancers diagnosed worldwide is a skin cancer, according to the American Cancer Society. And up to 95% of malignant melanomas are caused by excessive sun damage, found research from the International Agency for Research on Cancer. “The risks associated with sun exposure are well mapped and well understood, and we have proof that using sunscreen lowers these risks,” Lim stresses.

“Sunburns are bad. There’s just no way around it,” says Kerry M. Hanson, a chemist at the University of California, Riverside, who has studied sunscreens extensively and has also worked with sunscreen manufacturers. “Protecting oneself from sunburn is critical to prevent skin cancers later in life,” she says. And to protect against sunburn, Hanson says sunscreen is proved to be effective — if it’s applied properly.

A recent study from the University of Queensland in Australia found people who followed proper sunscreen-application practices on a daily basis developed roughly 50% fewer melanomas than those who were left alone to use (or not use) sunscreen as they saw fit. Similar research efforts have uncovered proof of sunscreen’s effectiveness at blocking the development of squamous-cell and basal-cell cancers as well.

Unfortunately, Lim says many people don’t rub on nearly enough of the stuff to protect themselves. You need to spread on 1 oz. — or about the amount that would fill a shot glass — to safeguard your whole body for just a couple hours, he says. And that’s assuming you’re not sweating or swimming, in which case you need to apply more frequently.

In the end, he says the greatest danger of sunscreen may be that it provides people with a false sense of security against the sun’s dangers. “Just because you rub some on in the morning doesn’t mean you’re safe spending all day in the sun,” he says.

TIME medicine

World’s First Malaria Vaccine Could Be a Year Away

A Thai public-health official places a thermometer into a child's mouth at a malaria clinic in Sai Yoke district, Kanchanaburi province, Thailand, on Oct. 26, 2012 Sukree Sukplang—Reuters

Researchers published promising findings, while a pharmaceutical company applied for the first-ever regulatory approval of malaria vaccine

The world’s first malaria vaccine may just be a year away, after a thorough trial of a new drug showed promising results.

PLOS Medicine on Tuesday published a study, in which researchers found that for every 1,000 children who received the vaccine, 800 cases of illness could be prevented. The children also retained protection 18 months after being injected.

Now, pharmaceutical manufacturer GlaxoSmithKline (GSK) has applied the drug for regulatory approval — the first time a malaria vaccine has reached this stage.

“This is a milestone,” Sanjeev Krishna, professor of molecular parasitology and medicine at St. George’s, University of London, who reviewed the paper for the journal, told the BBC. “The landscape of malaria-vaccine development is littered with carcasses, with vaccines dying left, right and center. We need to keep a watchful eye for adverse events, but everything appears on track for the vaccine to be approved as early as next year.”

Around 800,000 people die from malaria every year, most of them children under 5 in sub-Saharan Africa. Several African countries were involved in the trial of the new vaccine, which is developed by GSK in cooperation with the nonprofit Path Malaria Vaccine Initiative, for which they have received funding from the Bill & Melinda Gates Foundation.

TIME fitness

Study: Running 5 Minutes a Day Could Add Years to Your Life

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According to a new study published in the Journal of the American College of Cardiology, running 5 minutes per day can reduce an individual’s risk of premature death by about 3 years. Researchers found that people who ran less than an hour per week also saw an increase in lifespan, not just a decrease in risk of premature death. The study took place over the course of 15 years, testing participants ranging in age from 18-100.

Separate research found that running more than 20 miles per week could take years off an individual’s life, providing further evidence that less can be more with regard to exercise. According to that research, individuals who exhibit consistent but moderate workout patterns are likely to live the longest.

TIME Mental Health/Psychology

What 28-Years of Solitary Confinement Does to the Mind

Alone prisonner
Getty Images

One Louisiana prisoner may get out of solitary confinement after nearly 30 years

Kenny “Zulu” Whitmore, 59, has spent the last 28 consecutive years in solitary confinement in Louisiana State Penitentiary at Angola, but a prison warden says he may be released to the general inmate population.

Whitmore reportedly spends 23 hours a day in a 6-foot by 9-foot cell. “We will get him out,” Warden Burl Cain, warden of the prison, told the Medill Justice Project, a group that investigates potentially wrongful convictions. “We’d rather him out. I need his cell. I’ve got some young people, predators, that need to be in that cell. When I can conclude he’s not going to cause me the blues, then he can come out of the cell.” Whitmore is in prison for second-degree murder.

According to the Medill Justice Project, Whitmore’s eyesight has deteriorated and he has hypertension. And if he’s similar to other cases of prisoners in solitary confinement, his health and mental health have likely deteriorated in other ways, too.

“Human beings require two very basic things: social interaction and meaningful activity. By doing things we learn who we are and we learn our worth as a person. The two things solitary confinement does is make people solitary and idle,” says Dr. Terry Kupers, a professor of psychiatry at the Wright Institute in Berkeley California, who has spent over 40 years interviewing thousands of solitary confinement prisoners.

Though the impact of solitary confinement can differ person to person, there are some basic symptoms that are particularly widespread among inmates. Prisoners of long-term confinement—which Kupers says that’s about three months, though for some effects start to appear much sooner—often experience high anxiety that can cause panic attacks, paranoia and disordered thinking, as well as anger and compulsive actions, like pacing or repeatedly cleaning the cell. Basic cognitive functions are also dulled. “I have prisoners tell me they quit reading, which is one of the only things you can sometimes do,” says Kupers. “I ask why, and they say it’s because they can’t remember what they read three pages before.”

Prisoners in solitary confinement often develop confusion over when to be alert and when to sleep. In a report, Psychiatric Effects of Solitary Confinement, Stuart Grassian, a former faculty member at the Harvard Medical School and a consultant in criminal cases writes: “[Solitary confinement prisoners] often find themselves incapable of resisting their bed during the day—incapable of resisting the paralyzing effect of their stupor—and yet incapable of any restful sleep at night. The lack of meaningful activity is further compounded by the effect of continual exposure to artificial light and diminished opportunity to experience natural daylight.”

Grassian tells TIME that without stimulation, people’s brains will move toward stupor and delirium—and often people won’t recover from it.

Even when prisoners are let out of solitary confinement, Grassian says, they are so overwhelmed by stimulus that they become incapable of tolerating their new environment and have trouble integrating back into the general population. Their brain waves jump and they become highly reactive. “I’ve talked to many of these prisoners who say it’s hellish for them,” says Grassian. “The often end up spending a tremendous amount of time in their cell.”

Whether Whitmore will be released into the general prison population remains uncertain but the fact that he has been attempting to take legal action against the prison may work in his mental favor, since Grassian says thinkers tend to do better.

“People that can use their minds tend to do relatively better,” he says. “They are able to maintain a degree of stimulation internally.”

And that’s all many can rely on.

TIME Mental Health/Psychology

The Part of Your Brain That Senses Dread Has Been Discovered

This tiny part of your brain tracks bad experiences

A tiny part of the brain can keep track of your expectations about negative experiences—and predict when you will react to an event—researchers at University College London say.

The brain structure, known as the habenula, activates in response to negative events such as electric shocks, and they may help people learn from bad experiences.

The findings, published in Proceedings of the National Academy of Sciences, marks the first time this association has been proven in humans. Earlier studies showed that the habenula causes animals to avoid negative stimuli by suppressing dopamine, a brain chemical that drives motivation.

In this study, investigators showed 23 people random sequences of pictures followed by a set of good or bad outcomes (an electric shock, losing money, winning money, or neutral). The volunteers were asked to occasionally press a button to show they were paying attention, and researchers scanned their brains for habenula activity using a functional magnetic resonance imaging (fMRI) scanner. Images were taken at high resolution because the habenula is so small—half the size of a pea.

When people saw pictures associated with painful electric shocks, the habenula activated, while it did not for pictures that predicted winning money.

“Fascinatingly, people were slower to press the button when the picture was associated with getting shocked, even though their response had no bearing on the outcome,” lead author Rebecca Lawson from the University College London Institute of Cognitive Neuroscience, said in a statement. “Furthermore, the slower people responded, the more reliably their habenula tracked associations with shocks. This demonstrates a crucial link between the habenula and motivated behavior, which may be the result of dopamine suppression.”

The study also showed that the habenula responds more the worse an experience is predicted to be. For example, researchers said the habenula responds much more strongly when an electric shock is certain than when it is unlikely to happen. This means that your brain can tell how bad an event will be before it occurs.

The habenula has been linked to depression, and this study shows how it could play a part in symptoms such low motivation, focusing on negative experiences and pessimism in general. Researchers said that understanding the habenula could potentially help them develop new ways of treating depression.

TIME fitness

63% of Americans Actively Avoid Soda

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Crushed can Getty Images

The soda craze is going flat–at least, according to a new Gallup poll, which found that almost two-thirds of Americans actively avoid soda in their diet.

While 41% percent of those polled in 2002 said that they try to steer clear of soda, that number has now jumped to 63%. Gallup’s poll shows that generally Americans are making more effort to have healthier diets. More than nine out of ten Americans try to include fruits and vegetables in their diets, and 52% said that they are trying to avoid sugars.

Don’t start pouring one out for the dying soda business just yet, though. A 2012 Gallup poll also found that 48% of Americans drink at least one glass of soda a day.

TIME polio

The Battle to Eradicate Polio in Pakistan

A Pakistani health worker vaccinates a child in Islamabad
A Pakistani health worker vaccinates a child in Islamabad Anadolu Agency/Getty Images

Political unrest in Pakistan has been a gift to the poliovirus, with 99 cases reported there so far this year. But Rotary International, which has already vaccinated 2 billion children in 122 countries, is hitting back hard

Epidemiology can be all about geography—and that’s especially true when it comes to polio. If you live in the U.S., where polio was eradicated in 1979, the specter of the disease has faded almost entirely, though pockets of infections can occur among the unvaccinated. In Pakistan, however, things are moving in precisely the opposite direction, and have been for a while now.

One of only three countries in the world where polio remains endemic (the other two are Nigeria and Afghanistan), Pakistan had been close to joining the world’s polio-free nations, with only 58 infections in 2012. But thanks to bans on vaccinating—and deadly attacks on polio fieldworkers—by the Pakistani Taliban, the caseload rose to 93 in 2013. In 2014, the total reached 99 by July 18—a figure all the more alarming compared to this point last year, when there had been just 21 cases.

“It’s a scary number,” says Aziz Memon, Pakistani chairman of Rotary International’s polio eradication campaign. “Children in North Waziristan have been trapped for three and a half years without a drop of polio vaccine, and that’s what’s causing this.”

The folks at Rotary know what they’re talking about. Since launching their polio eradication effort in 1985, they have been responsible for the vaccination of 2 billion children in 122 countries. Along with the World Health Organization, UNICEF, The Gates Foundation and others, they have helped slash the global infection rate from 350,000 cases per year in 1988 to 416 in 2013.

That’s indisputably good news, but polio is an exceedingly sneaky virus, with 200 symptom-free carriers for every one case of the disease. That fact, combined with the anti-vaccine forces in Pakistan, not to mention the porous borders cause by war and unrest in the overall region, has caused the disease to leak out from the three endemic countries, with stray cases turning up in Equatorial Guinea, Iraq, Cameroon, Syria, Ethiopia, Somalia and Kenya. In a handful of other countries, the virus has been detected in sewage, but it has not led to any cases of the disease—yet.

It’s Pakistan though that’s considered ground zero, and Rotary has announced that it’s now deploying some very simple weapons in what has always been a village-to-village, door-to-door battle. To improve surveillance and tracking—a maddeningly difficult job in a country in which so many people live off the communications grid—Rotary has distributed hundreds of cell phones to midwives who circulate through communities, canvassing residents to find out who has received the vaccine and who has been overlooked. Information on the unvaccinated kids—the “missing children” in the fieldworkers argot—is entered into the phones and uploaded to a central spreadsheet, allowing later vaccinators to target their efforts more precisely.

“The midwives also track pregnant mothers,” says Memon. “And when their children are born they can continue to maintain complete health records, not just for polio but for other vaccines and basic health care as well.”

Rotary has also worked with The Coca-Cola Company to build what’s known as a reverse osmosis water plant—essentially a sophisticated filtration facility—in the town of Malin, within the city of Karachi. Polio is a disease spread almost entirely by human waste, and once it leeches into the water system it can spread nearly anywhere. The Malir plant, which was constructed near a school to give polio-age kids the first access to the newly filtered water, is a relatively modest one, with just 20,000 gal. (76,000 liters) of clean water on hand at any one moment, and cost only $40,000 to build. But as a pilot project it represents a very good start. “We can’t build a massive plant like the government can,” says Memon. “This is a small plant for a small community.”

One thing, paradoxically, that’s working in the vaccinators’ favor is the increased number of displaced people in Pakistan. A recent push by the Pakistani military to flush the Taliban from its safe havens has broken the vaccination blockade, and already 350,000 children have received at least one dose of the polio vaccine. But 1.5 million refugees are scattered around the country. Rotary has dispatched field workers to refugee camps and transit points to identify the children and few adults who need the polio vaccine and administer it on the spot.

“The government did not have any idea about what the numbers of displaced people would be,” says Memon. In the refugee camps, he adds, there are at least 40,000 pregnant women, whose babies will have to be vaccinated shortly after birth.

The diabolical thing about polio—and indeed any disease science hopes to eradicate—is that even one case is too many. As long as any wild poliovirus is out there, everyone needs to be protected. It is only when the last scrap of virus has been found and snuffed, that the protective push can stop. That has happened once before in medical history—with smallpox. In the case of polio, it’s tantalizingly close to happening again.

TIME Aging

3 Simple Lifestyle Habits That May Slow Aging

There's more evidence for eating well, sleeping, and exercising

Stress makes our bodies age faster, but thankfully we can combat that with healthy eating and exercise, a new study says.

When cells age, telomeres—tips at the end of chromosomes—shorten. Telomeres help regulate the aging of cells, and their length has been used to determine the body’s current state of health. Things like stress and lifestyle behaviors can influence their length, as compelling earlier research has shown. In the new study, University of California, San Francisco, researchers looked at 239 post-menopausal women for a year and found that for every major life stressor they experienced during the year, there was a significant shortening in their telomere length.

That’s not great news, but the researchers also discovered that the women who ate a healthy diet, exercised and slept well had less shortening of their telomeres. It could be that the women’s healthy habits actually protect them from cellular aging, even in the face of life’s stresses.

The study, which is published in the journal Molecular Psychiatry, is observational, which means the researchers cannot say with certainty that it was these healthy lifestyles alone that offered them protective benefits. But at the very least, it shows once again that doing our best to eat well, sleep, and exercise can give us an edge.

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