By BRYSON VOIRIN The morning after our first successful frigate bird capture, I slowly creep through the thorny brush toward the field tent to check up on the female. It’s been about 12 hours since I put her back on her nest with a sleep logger and GPS unit, and I’m keen to see how she is doing, and if she is still here or if she has switched with her mate and is out foraging. Gazing through my binoculars, I spot her, sitting alert on her nest. I breathe a deep sigh of relief, knowing that her late-night capture did not cause nest abandonment. As in any zoology fieldwork, our first priority is the well-being of our study species. Before starting any project with animals, there is a stringent animal care committee that reviews and approves our protocols and procedures. Even though previous work on frigate birds shows that the birds would not be spooked off their nests, seeing this confirmed the morning after is a welcome sign. Her sleep logger is still attached and looking fine, held on by the curious skin glue. I watch her head movements as she follows other birds floating overhead; she doesn’t seem affected at all by the device. However, judging by the angry glare she gives me, my presence is making her nervous. I want to avoid stressing the female any more than necessary, so I head back to camp and leave her alone for the rest of the day. The next morning Sebastian Cruz reports back that a male has switched with her on the nest, meaning that she is out foraging. By the pinkish color of his throat we can tell that this is her nesting mate. Had she abandoned her nest, and another male taken over, that male would have a bright red inflated gular sac. © 2011 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 15306 - Posted: 05.09.2011

By CLAUDIA WALLIS An ambitious six-year effort to gauge the rate of childhood autism in a middle-class South Korean city has yielded a figure that stunned experts and is likely to influence the way the disorder’s prevalence is measured around the world, scientists reported on Monday. The figure, 2.6 percent of all children aged 7 to 12 in the Ilsan district of the city of Goyang, is more than twice the rate usually reported in the developed world. Even that rate, about 1 percent, has been climbing rapidly in recent years — from 0.6 percent in the United States in 2007, for example. But experts said the findings did not mean that the actual numbers of children with autism were rising, simply that the study was more comprehensive than previous ones. “This is a very impressive study,” said Lisa Croen, director of the autism research program at Kaiser-Permanente Northern California, who was not connected with the new report. “They did a careful job and in a part of the world where autism has not been well documented in the past.” For the study, which is being published in The American Journal of Psychiatry, researchers from the Yale Child Study Center, George Washington University and other leading institutions sought to screen every child aged 7 to 12 in Ilsan, a community of 488,590, about the size of Staten Island. By contrast, the Centers for Disease Control and Prevention in the United States and most other research groups measure autism prevalence by examining and verifying records of existing cases kept by health care and special education agencies. That approach may leave out many children whose parents and schools have never sought a diagnosis. © 2011 The New York Times Company

Keyword: Autism
Link ID: 15305 - Posted: 05.09.2011

Matt Kaplan Modern mammals often live in groups, but most marsupials are solitary. With no fossil evidence to suggest that the animals have ever behaved otherwise, palaeontologists have long assumed that marsupials have been loners throughout their evolutionary history. This notion is now being overturned by the analysis of a fossil site containing many marsupials that seem to have been living together. The site, in the Tiupampa locality of Bolivia, contains 35 specimens of Pucadelphys andinus, a primitive opossum from the early Palaeocene Epoch (64 million years ago). Teeth are usually all that palaeontologists can find of ancient mammals, because dentition is built to endure punishment, and fossilizes well. However, 22 of the 35 specimens at the Bolivian site consist of teeth, skulls and body skeletons in near-perfect shape. Sandrine Ladevèze, a palaeontologist at the Royal Belgian Institute of Natural Sciences in Brussels, and her colleagues publish an analysis of the specimens today in Nature1. "To find a sample of this quality is almost unheard of," says Richard Cifelli, a palaeontologist at the University of Oklahoma in Norman. Full house But it is not the condition, but the placement of the specimens at the fossil site that intrigued Ladevèze. © 2011 Nature Publishing Group

Keyword: Evolution
Link ID: 15304 - Posted: 05.09.2011

By Ella Davies Stress may play a crucial role in determining whether some birds mimic the sounds of others, say researchers. Scientists studied the vocal repertoire of bowerbirds. Best known for their elaborate nests or "bowers", the birds can also copy up to fifteen sounds. Bowerbirds were previously thought to mimic predators as a form of defence. But recordings reveal they prefer to copy a variety of alarm calls made by bird species that are either bullying each other, or which feel threatened. That suggests that the birds learn and reproduce calls only in stressful situations, say the researchers. Spotted bowerbirds (Ptilonorhynchus maculatus) are found in Australia and New Guinea and are best known for their elaborate "bowers", created by males seeking to impress a mate. Reports from egg collectors led scientists to believe the birds mimicked the calls of predators as a way of defending their territory. However, researchers from the University of St Andrews, UK and Deakin University, Geelong, Victoria, Australia found different results in their study. They have published details in the journal Naturwissenschaften. BBC © 2011

Keyword: Stress; Language
Link ID: 15303 - Posted: 05.09.2011

By Katherine Harmon The people we associate with can have a powerful effect on our behavior—for better or for worse. This holds true for human health and body mass, too. The heavier our close friends and family, the heavier we are likely to be. This correlation, described in 2007 by a team that analyzed data from the longitudinal Framingham Heart Study, is well established. But just how this transpires—whether via shared norms, common behavior or just similar environments—has been the subject of much debate. The authors of the 2007 study proposed that social norms shared among friends and relatives might be a strong determinant of body mass index (BMI). And a new study, published online May 5 in the American Journal of Public Health, drills down to see just how these social forces might be at work. The study of more than 100 women—and hundreds of their friends and family members—however, suggests that social attitudes might not be key in determining obesity clusters after all. "Going in as anthropologists we assumed that the norms would have a strong influence" on BMI, says Alexandra Brewis, executive director of the School of Human Evolution and Social Change at Arizona State University in Tempe. She and her colleagues found themselves surprised how small an effect the norms had on a person's BMI. Just one type of social dynamic seemed to play a statistically significant role—and that was only about 20 percent. © 2011 Scientific American,

Keyword: Obesity
Link ID: 15302 - Posted: 05.07.2011

By Bruce Bower Depression may have an analytical upside. People hospitalized for this mood disorder display a flair for making good choices when many options must be considered one at a time, a new study finds. Depression may prompt an analytical thinking style suited to solving sequential problems, such as deciding when to stop a house hunt and purchase a property or when to stop playing the field and marry a suitor, say psychologist Bettina von Helversen of the University of Basel in Switzerland and her colleagues. It’s also possible that depressed people adopt a pessimistic outlook that encourages a thorough evaluation of available options, von Helversen's team suggests in an upcoming Journal of Abnormal Psychology. “Depression may improve sequential decision making, which includes some high-stakes choices,” she says. Von Helversen’s study is the first to demonstrate a thinking advantage for clinically depressed patients, possibly because — unlike previous studies of people with the ailment — the team used a quantitative measure to evaluate the accuracy of realistic social choices, remarks psychologist Paul Andrews of Virginia Commonwealth University in Richmond. Andrews hypothesizes that depression evolved as an emotional response that induces people to isolate themselves and single-mindedly resolve painful personal problems. “Depressive cognition is more complex than has been assumed by clinicians,” he says. © Society for Science & the Public 2000 - 2011

Keyword: Depression
Link ID: 15301 - Posted: 05.07.2011

By Susan Gaidos Emery Brown knows how to take the sting out of surgery. As an anesthesiologist, he has steered hundreds of patients to pain-free oblivion, allowing doctors to go about their business resetting bones, repairing heart valves or removing tumors. During surgery he continually monitors his patients, keeping tabs on their heart rate, blood pressure and breathing. Recently, he has also been eyeing what happens in their brains. Rather than going under the knife, some of the people in Brown’s care are going into scanners to reveal how the brain responds when people are knocked out. These deep glimpses could answer vexing questions about how people enter the state of unconsciousness known as general anesthesia and what happens in the brain while they are there. Although it is widely used and remarkably effective, anesthesia’s neural mechanisms have long remained mostly mysterious. While every anesthetic drug has its own effect, scientists know little about how the various versions work on the brain to transport patients from normal waking awareness to dreamless nothingness. Understanding how such compounds meddle with the nervous system might lead to anesthetics capable of tweaking neural circuits more precisely, delivering only what is needed where it’s needed, says Brown, of Massachusetts General Hospital in Boston. Fine-tuning the drugs’ effects could also help doctors bring patients into and out of consciousness more quickly and safely, avoiding the side effects that can occur when medications act at brain sites other than those intended or act at targeted sites for too long a time. © Society for Science & the Public 2000 - 2011

Keyword: Sleep
Link ID: 15300 - Posted: 05.07.2011

By Victoria Gill Wild chimpanzees use at least 66 distinct gestures to communicate with each other, according to scientists. A team of researchers from the University of St Andrews in Scotland filmed a group of the animals in order to decipher this "gestural repertoire". The team then studied 120 hours of footage of the chimps interacting, looking for signs that the animals were intentionally signalling to each other. The findings are published in the journal Animal Cognition. Previous studies on captive chimps have suggested the animals have about 30 different gestures. "So this [result] shows quite a large repertoire," lead researcher Dr Catherine Hobaiter told BBC News. "We think people previously were only seeing fractions of this, because when you study the animals in captivity you don't see all their behaviour. "You wouldn't see them hunting for monkeys, taking females away on 'courtships', or encountering neighbouring groups of chimpanzees." Dr Hobaiter spent 266 days observing and filming a group of chimpanzees in Budongo Conservation Field Station, Uganda. BBC © 2011

Keyword: Language; Evolution
Link ID: 15299 - Posted: 05.07.2011

by Jessica Hamzelou Those who are easily distracted from the task in hand may have "too much brain". So says Ryota Kanai and his colleagues at University College London, who found larger than average volumes of grey matter in certain brain regions in those whose attention is readily diverted. To investigate distractibility, the team compared the brains of easy and difficult-to-distract individuals. They assessed each person's distractibility by quizzing them about how often they fail to notice road signs, or go into a supermarket and become sidetracked to the point that they forget what they came in to buy. The most distractible individuals received the highest score. The team then imaged the volunteers' brains using a structural MRI scanner. The most obvious difference between those who had the highest questionnaire scores – the most easily distracted – and those with low scores was the volume of grey matter in a region of the brain known as the left superior parietal lobe (SPL). Specifically, the easily distracted tended to have more grey matter here. To find out whether activity in the left SPL plays a role in distractibility, the team turned to transcranial magnetic stimulation. This hand-held magnet dampens the activity of the part of the brain beneath it for around half an hour. © Copyright Reed Business Information Ltd.

Keyword: ADHD; Attention
Link ID: 15298 - Posted: 05.07.2011

By LISA SANDERS, M.D. A fiercely independent and active 76-year-old woman spent the past decade caring for her aged mother, who died at 99. Weeks after her mother’s death, the woman collapsed at home. She was found to have bleeding from a collection of abnormal blood vessels (known as AVMs, or arteriovenous malformations) in her colon. In the months after, the patient’s red-blood-cell count returned to normal, but she never regained her old energy and strength. She told her daughters that she was weaker and more tired than she had ever been in her life. Dr. Susan Wiskowski, a family physician in Hartford, was the woman’s doctor. Until recently, the patient was in good health for her age, with only a few medical problems: high blood pressure, which was controlled with one medication; hypothyroidism, treated with Synthroid; and cataracts, which had been surgically repaired. Now, out of the blue, she was experiencing rapid weight gain, swelling and weakness in her legs, which made it hard to walk. A couple of weeks after the cardiac work-up, the patient’s behavior became erratic and strange. Despite her complaints of weakness, she veered between bursts of activity — endlessly cleaning her house, giving large dinner parties — and days of isolation and fatigue. She was sometimes elated, telling her four daughters that she’d found where heaven was located. She began to talk about giving away her possessions. One afternoon she seemed completely out of control. A neighbor called 911, and the patient was rushed by ambulance to St. Francis Hospital in Hartford. © 2011 The New York Times Company

Keyword: Hormones & Behavior
Link ID: 15297 - Posted: 05.07.2011

by Laurent Banguet and Marlowe Hood, AFP Chimpanzees are self-aware and can anticipate the impact of their actions on the environment around them, an ability once thought to be uniquely human, according to a study released Wednesday. The findings, reported in the Proceedings of the Royal Society B, challenge assumptions about the boundary between human and non-human, and shed light on the evolutionary origins of consciousness, the researchers said. Earlier research had demonstrated the capacity of several species of primates, as well as dolphins, to recognize themselves in a mirror, suggesting a fairly sophisticated sense of self. The most common experiment consisted of marking an animal with paint in a place -- such as the face -- that it could only perceive while looking at its reflection. If the ape sought to touch or wipe off the mark while facing a mirror, it showed that the animal recognized itself. But even if this test revealed a certain degree self-awareness, many questions remained as to how animals were taking in the information. What, in other words, was the underlying cognitive process? To probe further, Takaaki Kaneko and Masaki Tomonaga of the Primate Research Institute in Kyoto designed a series of three experiments to see if chimps, our closest cousins genetically, to some extent "think" like humans when they perform certain tasks. © 2011 Discovery Communications, LLC.

Keyword: Attention; Evolution
Link ID: 15296 - Posted: 05.05.2011

By Laura Sanders Easily distracted people can stop blaming their lack of focus on the royal wedding, Facebook feeds and hilarious YouTube videos of honey badgers. Rather, a small network of cells in the back left part of the brain may be the culprit, researchers report in the May 4 Journal of Neuroscience. Knowing how the brain focuses on what’s important — and filters out noise — may help scientists come up with ways to counteract attention disorders. “Attention has a huge effect on our lives,” says cognitive neuroscientist Carmel Mevorach of the University of Birmingham in England, who was not involved in the study. “Everything we do — literally, everything we do — is affected by attention.” In this age of information overload, appropriating attention is a challenge, says study coauthor Ryota Kanai of University College London, and some people are much more susceptible to distractions. Kanai and his colleagues wanted to know if brain differences could explain why some people are easily distracted while others stay focused. For the study, 145 volunteers filled out a survey called the Cognitive Failures Questionnaire, which asks people to rate how frequently they experience mental lapses such as forgetting what they came to a shop to buy or bumping into people. Volunteers’ answers were used to calculate each person’s overall susceptibility to distraction in everyday life. (Incidentally, scores on the same questionnaire also predict how many car accidents someone has.) © Society for Science & the Public 2000 - 2011

Keyword: Attention; ADHD
Link ID: 15295 - Posted: 05.05.2011

By Rebecca Tuhus-DubrowPosted Last week, new guidelines for diagnosing Alzheimer's defined a "preclinical" stage of the dreaded disease. Evidently, the telltale pathology—in particular, the plaques that encroach on the brain—can be detected years, if not decades, before the patient ever forgets a familiar name or neglects to feed a pet. The announcement renewed a debate that has flared in recent months: Since there's no cure, critics believe that an early diagnosis of Alzheimer's would serve only sadistic doctors, masochistic patients, and greedy business interests. They worry that Big Pharma will sell snake oil to a huge, desperate market, and that health insurance companies and employers could use the information against patients. Others, however, point to the benefits of advance notice. You might take that long-deferred trip to Antarctica, for example, or try to squeeze in extra visits to the elliptical machine. (There is some evidence, albeit inconclusive, that exercise helps stave off the mind's deterioration.) Complicating matters, the "bio-markers" that show up in an early diagnosis do not necessarily lead to symptoms. For unclear reasons, some brains seem to function well despite the incursion, while others succumb more readily. In many cases, patients die from other causes before the plaques wreak havoc. Given the gaps in knowledge, the guidelines stress that the tests are for research purposes only. (The idea is that studying the earliest manifestations of the disease will illuminate its genesis and ultimately yield therapies that keep symptoms at bay.) Yet some are concerned that before long, bio-markers will be used to test regular patients. What are the implications of diagnosing an incurable disease in seemingly healthy people? © 2011 The Slate Group, LLC

Keyword: Alzheimers
Link ID: 15294 - Posted: 05.05.2011

Lucas Laursen Nuclear accidents can have devastating consequences for the people and animals living in the vicinity of the damaged power plants, but they also give researchers a unique opportunity to study the effects of radiation on populations that would be impossible to recreate in the lab. Tim Mousseau, who directs the Chernobyl Research Initiative at the University of South Carolina in Columbia, together with an international team, is studying the long-term ecological and health consequences of the 1986 accident at the Chernobyl nuclear power plant in the Ukraine. Mousseau has been studying Chernobyl since 1998 and his latest work, carried out with colleagues in France and published in Oecologia last month, finds that bird species with orange feathers living in the fallout zone seem to be more susceptible to radiation than their drabber gray and black fellows1. They suggest that production of the more colourful pigments consumes antioxidant molecules that would otherwise confer protection against radiation damage, and that this molecular trade-off is shaping bird populations around the former nuclear power plant. One of the team, Anders Møller from the Pierre and Marie Curie University in Paris, donned a radiation-protection suit to make four bird-watching trips between 2006 and 2009 to the Red Forest and other locations around Chernobyl. In a 2007 analysis of the data from the first bird counts made in spring 2006, Mousseau and Møller found that birds whose feathers were coloured with bright yellow and red carotenoid-based pigments showed a decline in abundance as radiation levels increased, though there was no comparable correlation for bird species with melanin-based colouring, such as brown, black and reddish-brown2. The new study takes the analysis a step further by teasing out the different protective effects of different types of melanin pigment. © 2011 Nature Publishing Group,

Keyword: Evolution
Link ID: 15293 - Posted: 05.05.2011

by Burkhard Bilger When David Eagleman was eight years old, he fell off a roof and kept on falling. Or so it seemed at the time. His family was living outside Albuquerque, in the foothills of the Sandia Mountains. There were only a few other houses around, scattered among the bunchgrass and the cholla cactus, and a new construction site was the Eagleman boys’ idea of a perfect playground. David and his older brother, Joel, had ridden their dirt bikes to a half-finished adobe house about a quarter of a mile away. When they’d explored the rooms below, David scrambled up a wooden ladder to the roof. He stood there for a few minutes taking in the view—west across desert and subdivision to the city rising in the distance—then walked over the newly laid tar paper to a ledge above the living room. “It looked stiff,” he told me recently. “So I stepped onto the edge of it.” In the years since, Eagleman has collected hundreds of stories like his, and they almost all share the same quality: in life-threatening situations, time seems to slow down. He remembers the feeling clearly, he says. His body stumbles forward as the tar paper tears free at his feet. His hands stretch toward the ledge, but it’s out of reach. The brick floor floats upward—some shiny nails are scattered across it—as his body rotates weightlessly above the ground. It’s a moment of absolute calm and eerie mental acuity. But the thing he remembers best is the thought that struck him in midair: this must be how Alice felt when she was tumbling down the rabbit hole. Eagleman is thirty-nine now and an assistant professor of neuroscience at Baylor College of Medicine, in Houston. Physically, he seems no worse for the fall. He did a belly flop on the bricks, he says, and his nose took most of the impact. “He made a one-point landing,” as his father puts it. The New Yorker © 2011 Condé Nast Digital.

Keyword: Attention
Link ID: 15292 - Posted: 05.03.2011

By NATALIE ANGIER Just when you thought that serotonin was passé, and you’d tossed all your half-used bottles of S.S.R.I.-type antidepressants because the ones that didn’t give you nausea or smother your libido left you wondering whether you were in the placebo arm of a clinical trial, here comes a raft of new discoveries that sweeps the small, evolutionarily ancient and slyly powerful signaling molecule back on to center stage. Researchers lately have learned that serotonin plays an impressive number of critical roles throughout the body, both below the neck and above it, and from the earliest days of prenatal pre-sentience. One team has found that serotonin starts seeping into the embryonic forebrain during the first trimester of pregnancy, helping to shape the basic neural circuitry that later in life will be applied to learning, emoting and consulting a psychiatrist. More surprising still, Pat Levitt of the Zilkha Neurogenetic Institute at the University of Southern California and his colleagues reported in the April 21 issue of the journal Nature, the creator of all that architectonic prenatal serotonin turns out to be an organ long dismissed as a passive sieve: the placenta. Other researchers have determined that serotonin in the gut helps orchestrate the remodeling of bone, the lifelong buildup and breakdown of osteoclasts and osteoblasts that make the human skeleton such an exciting organ system to own. The latest findings may never lead to a satisfying pharmacologic fix for what the psychiatrist Kay Redfield Jamison has called “ordinary existential angst” and others “terminal you-ness,” but they may someday help stiffen the spine, and they remind us that it’s worth listening to serotonin no matter what it has to say. © 2011 The New York Times Company

Keyword: Development of the Brain; Depression
Link ID: 15291 - Posted: 05.03.2011

By JANE E. BRODY Steve Riedner of Schaumberg, Ill., was a 55-year-old tool-and-die maker, a job that involves difficult mental calculations, and a frequent speaker at community meetings when he found himself increasingly at a loss for words and unable to remember numbers. He even began to have difficulty reading his own written comments. The neurologist he consulted thought Mr. Riedner had suffered a stroke and for three years treated him with cholesterol-lowering medication. But instead of his language ability stabilizing or improving, as should happen following a stroke, it got worse. A second neurologist concluded after further testing that Mr. Riedner might have a condition called primary progressive aphasia, or P.P.A., a form of dementia affecting the brain’s language center. Having seen only one other case in his career, the neurologist referred Mr. Riedner and his wife, Mary Beth, to the Cognitive Neurology and Alzheimer’s Disease Center at Northwestern University, whose director, Dr. M. Marsel Mesulam, is perhaps the world’s leading expert on this relatively rare disorder. P.P.A. is a clinical syndrome, one of several forms of brain disease lost in the medical shadow of their much better known relative Alzheimer’s disease. While hardly as common as Alzheimer’s, P.P.A. is often misdiagnosed, and many patients like Mr. Riedner lose valuable time trying inappropriate and ineffective treatments. Though there is no cure, patients and families can learn ways to minimize the disabilities it causes. © 2011 The New York Times Company

Keyword: Language; Alzheimers
Link ID: 15290 - Posted: 05.03.2011

by John Travis Researchers this morning confirmed what former National Football League player Dave Duerson must have feared when he shot himself in the abdomen back in February, killing the 51 year old who had starred for several teams as a safety. An autopsy study showed that Duerson’s brain was riddled with classic signs of chronic traumatic encephalopathy (CTE), a form of brain damage that is becoming an increasing concern among athletes in violent contact sports. Duerson’s form of suicide was apparently carefully chosen to preserve his brain as he had texted his family that he wanted the organ to be examined at the Boston University Center for the Study of Traumatic Encephalopathy (CSTE). At a press conference there today, researchers reported that there was evidence of moderately advanced CTE in several regions of Duerson’s brain, including the frontal cortex, amygdala, and hippocampus, which play roles in impulse control, mood, memory, and other cognitive functions. “Dave Duerson had classic pathological CTE and no sign of any other disease,” neuropathologist and CSTE Co-Director Ann McKee told the press conference. McKee notes that there’s evidence suggesting CTE predisposes people to suicide, although how remains unclear; a colleague called it a “chicken and the egg problem,” explaining that CTE may cause problems in life that encourage suicides rather than specifically promote suicidal behavior by altering the working of the brain. Collisions that cause concussions and even lesser hits appear to spur the development of CTE. At the press conference CSTE Co-Director Chris Nowinski, a former college football player and professional wrestler, urged youth football coaches to carefully control how much violent contact there is during practices as to reduce the overall number of hits. © 2010 American Association for the Advancement of Science.

Keyword: Brain Injury/Concussion
Link ID: 15289 - Posted: 05.03.2011

By Phyllis Richman, With apologies to Michael J. Fox, I must say Parkinson’s disease is not the best thing that ever happened to me. Picture this: One Sunday evening I walked up the street for a “meet the neighbors” party, eager to make connections in my new neighborhood. My husband decided to stay home. No problem, the party was nearby. I didn’t even take my purse: 11 years into Parkinson’s, I’ve pared down what I carry. I was burdened enough with my walking stick, a house key and a covered tray of chocolate mousses I’d made for the potluck. I’d verified on MapQuest that the address was no more than a couple of blocks away, the outer limit of my walking ability nowadays. I was looking for house number 425. It didn’t exist. The house numbers jumped from 423 to 500. I grew anxious. With Parkinson’s, stress seems to instantly drain my brain of half of its dopamine. It makes my back ache, my legs weaken and my foot curl. I tried to relax as I rested my tray on the hood of a parked car. Surely some other partygoers would come by and direct me. This is who came by: A woman with a couple of children and an apple pie, on her way to a dinner. Two passersby who wished they knew where a party was. An energetic woman with a dog. Two men carrying fishing gear, who thought I might be looking for 525. * © 1996-2011 The Washington Post

Keyword: Parkinsons
Link ID: 15288 - Posted: 05.03.2011

By James Gallagher Health reporter, BBC News Middle aged people who are overweight but not obese, are 71% more likely to develop dementia than those with a normal weight, according to research. Previous studies have indicated a link between obesity and dementia. But a study 8,534 of Swedish twins, in the journal Neurology, suggests just being overweight is also a risk factor. About one out of every 20 people above the age of the 65 has dementia. The Alzheimer's Society said a healthy lifestyle could reduce the risk. Those with a body mass index (BMI) - which measures weight relative to height - greater than 30, who are classified as obese, were 288% more likely to develop dementia than those with a BMI between 20 and 25, according to the study. The clinically overweight, who have a BMI between 25 and 30, were 71% more likely. Dr Weili Xu, from the Karolinska Institute in Stockholm, told the BBC: "We found in this study that being overweight is also a risk for dementia later in life." "The risk is not as substantial as for [the] obese, but it has public health importance because of this large number of people worldwide who are overweight," Dr Xu added. The study says 1.6 billion adults are overweight worldwide. BBC © 2011

Keyword: Obesity; Alzheimers
Link ID: 15287 - Posted: 05.03.2011