Chapter 9. Homeostasis: Active Regulation of the Internal Environment
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By Jessica Shugart People who need sugary snacks to stay sharp throughout the day could be prisoners of their own beliefs. The brain works just fine without regular shots of sugar in people who believe their willpower is unlimited, a new study shows. “There's a dominant theory in psychology that willpower is limited, and whenever you exert yourself to do a hard task or to resist a temptation, you deplete this limited resource,” says psychologist Carol Dweck from Stanford University. Previous studies have shown that mental exertion diminishes blood glucose levels and that a person’s willpower can be rejuvenated by ingesting a sugary drink. But Dweck’s earlier work led her to suspect that people’s attitudes about willpower may be responsible for that effect. In the new study, published online August 19 in the Proceedings of the National Academy of Sciences, Dweck, along with colleagues at the University of Zurich in Switzerland, focused on how attitudes about willpower may shape a person’s sugar dependence in the face of a challenge. The scientists also tested whether altering these beliefs might liberate a person from such a calorie-rich requirement. In the first of three experiments, the researchers asked students about their attitudes on willpower, then gave them lemonade sweetened with either sugar or a sugar substitute. Ten minutes after downing the sweet beverage, the students took tests of self-control and mental acuity. The students who subscribed to a self-generating belief about unlimited willpower scored equally well whether their drinks contained sugar or not. But the students who felt willpower was limited needed sugar to perform as well as the other group did. © Society for Science & the Public 2000 - 2013
By Cristy Gelling Repairing a faulty communication line between the gut and the brain can quell the urge to overeat, an experiment that cured chubby mice of their junk food addiction indicates. A similar strategy might be used to treat compulsive eating in people. Some scientists have proposed that, in both mice and humans, overeating can resemble drug addiction; the more food a person consumes, the less responsive the brain becomes to the pleasure of eating. By restoring normal communication between the gut and brain, researchers were able to resensitize overfed rodents to the pleasures of both fatty and healthy foods. "The therapeutic implications are huge,” says neuroscientist Paul Kenny of the Scripps Research Institute in Jupiter, Fla., who was not involved in the study. In the brain, a chemical called dopamine surges in response to pleasurable experiences like eating, sex and taking drugs. But brain-scanning studies suggest that obese individuals have muted dopamine reponses to food. These changes could lead overeaters to seek more and more food to satisfy their cravings, suggests study leader Ivan de Araujo of Yale University. De Araujo and his colleagues looked for ways to restore the dopamine response of overfed mice by studying the signals sent by their guts. In previous work, the researchers found that mice get a dopamine rush when fat is introduced directly into the small intestine via catheters. This shows that the gut communicates with the brain’s reward center even when the mouse can’t taste food. © Society for Science & the Public 2000 - 2013
Drinking several servings of soda a day is associated with behaviour problems such as aggression, a new study of preschoolers suggests. When researchers looked at 2,929 children in the U.S., they found 43 per cent of parents said their child had at least one serving of soda a day and four per cent had four or more servings daily. Four per cent of parents in the study reported their children had four or more servings of pop a day. Sugar and caffeine are potential triggers for behaviour, but parenting practices and home environment are also an influence.Four per cent of parents in the study reported their children had four or more servings of pop a day. Sugar and caffeine are potential triggers for behaviour, but parenting practices and home environment are also an influence. (Reuters) "In this large sample of five-year-old urban U.S. children, we found strong and consistent relationships between soda consumption and a range of problem behaviours, consistent with the findings of previous studies in adolescents," Shakira Suglia of Columbia University's Mailman School of Public Health in New York and her coauthors concluded in Friday's issue of the Journal of Pediatrics. Children who consumed four or more servings of soda per day were more than twice as likely to destroy things belonging to others, to get into fights and to physically attack people compared with children who drank no soda. Drinking four servings of soft drinks was associated with increased aggressive behaviour, even after accounting for factors such as TV viewing, candy consumption, maternal depression and intimate partner violence. © CBC 2013
Brian Owens Too much sugar is bad for you, but how much, exactly, is too much? A study in mice has found that the animals' health and ability to compete can be harmed by a diet that has sugar levels equivalent to what many people in the United States currently consume. High-sugar diets are associated not only with obesity and diabetes, but also with other human conditions such as coronary heart disease. However, the exact causal links for many of these has not been established. When studies are done in mice to evaluate health effects of sugar, the doses given are often so high, and outside the range of equivalent human consumption, that it is hard to tell conclusively whether the results are relevant to people. “Nobody has been able to show adverse effects at human-relevant levels,” says Wayne Potts, an evolutionary biologist at the University of Utah in Salt Lake City. But in a study published today in Nature Communications1, Potts and his colleagues looked at what happens under conditions comparable to the lifestyles of a substantial number of people in the United States. The researchers bred a pair of wild mice captured by Potts in a bakery, and fed offspring a diet in which 25% of the calories came from sugar. This is the maximum 'safe' level recommended by the US National Academies and by the US Department of Agriculture, and such a diet is consumed by around 13–25% of the US population. The safe level is roughly equivalent to drinking three cans of sugary drinks a day but having an otherwise sugar-free diet. © 2013 Nature Publishing Group
Link ID: 18509 - Posted: 08.14.2013
By Nathan Seppa High blood glucose levels appear to be associated with an increased risk of dementia in older people, a new study finds. Paul Crane at the University of Washington in Seattle and his colleagues recorded blood glucose levels in 2,067 people an average of 76 years old who initially had no signs of dementia. After five years, roughly one-fourth of the participants developed some form of dementia. Among people without diabetes, the risk of developing dementia was 18 percent greater in those with high blood glucose levels than in those with low levels. In people with diabetes, the risk of dementia was 40 percent higher in the high-glucose group, the scientists report in the Aug. 8 New England Journal of Medicine. The researchers took into account differences in age, gender, education, heart disease, blood pressure, smoking history and exercise level. While the study doesn’t establish a biological link between high blood glucose and dementia, the researchers speculate that the association could be explained by either glucose-related damage to tiny blood vessels in the central nervous system or insulin resistance – in which cells lose the ability to efficiently process sugar. © Society for Science & the Public 2000 - 2013
Link ID: 18476 - Posted: 08.08.2013
By ANAHAD O'CONNOR Losing sleep tends to make people eat more and gain weight, and now a new study suggests that one reason may be the impact that sleep deprivation has on the brain. The research showed that depriving people of sleep for one night created pronounced changes in the way their brains responded to high-calorie junk foods. On days when the subjects had not had proper sleep, fattening foods like potato chips and sweets stimulated stronger responses in a part of the brain that helps govern the motivation to eat. But at the same time, the subjects experienced a sharp reduction in activity in the frontal cortex, a higher-level part of the brain where consequences are weighed and rational decisions are made. The findings suggested that one unfortunate result of sleep loss is this “double hit” in brain activity, said Matthew P. Walker, an author of the study and a professor of psychology and neuroscience at the University of California, Berkeley. A sleepy brain appears to not only respond more strongly to junk food, but also has less ability to rein that impulse in. Some experts have theorized that in a sleep-deprived state, people eat more food simply to make up for all the calories they expend as they burn the midnight oil. But the new study showed that the changes in brain activity were evident even when the subjects were fed extra food and not experiencing any increased sensations in hunger. “Their hunger was no different when they were sleep deprived and when they had a normal night of sleep,” Dr. Walker said. “That’s important because it suggests that the changes we’re seeing are caused by sleep deprivation itself, rather than simply being perhaps more metabolically impaired when you’re sleep deprived.” Copyright 2013 The New York Times Company
By Scicurious I’ve got a terrible sweet tooth. And I am kind of proud of it, in a way. Yeah, I CAN eat that whole chocolate cake. I’d even LIKE it. Honeycomb dipped in chocolate? YES PLEASE. There are very few sweet things that I’d refuse. But should I really be ok with my sweet tooth? Could my sweet tooth correlate with something more sinister…a preference for alcohol? I can blame my sweet tooth on my parents, probably. Studies have shown that variability in preference for sweet things (though, to a greater or lesser extent, we all like sweet things), has a genetic basis. But the sweet tooth doesn’t go alone. In animals (mice especially), a preference for sugar in their water correlates with preference for alcohol as well. When you breed mice to make sure they drink alcohol (this is done to study alcoholism, for example), they also tend to really prefer sweet things, above and beyond mice that aren’t so into martinis. There is a correlation in humans, too. Humans who are more into sweet things are slightly more likely to abuse alcohol. But what is the basis? The authors of this study wanted to look at the reward related systems of humans, and see how sweet taste might compare to alcohol drinking. They took 16 people, put them in an fMRI scanner, and then carefully sprayed their tongues with sugar water. fMRI looks at the blood oxygen levels in various areas of the brain. Higher blood oxygen levels are thought to correlate with increased “activity” of the brain (the idea being that more neurons in use means the area needs more oxygen). An example of this would be that your visual cortex will show increased blood oxygen levels when you are looking at something. © 2013 Scientific American
By Meghan Rosen In a spacious hotel room not far from the beach in La Jolla, Calif., Kelsey Heenan gripped her fiancé’s hand. Heenan, a 20-year-old anorexic woman, couldn’t believe what she was hearing. Walter Kaye, director of the eating disorders program at the University of California, San Diego, was telling a handful of rapt patients and their family members what the latest brain imaging research suggested about their disorder. It’s not your fault, he told them. Heenan had always assumed that she was to blame for her illness. Kaye’s data told a different story. He handed out a pile of black-and-white brain scans — some showed the brains of healthy people, others were from people with anorexia nervosa. The scans didn’t look the same. “People were shocked,” Heenan says. But above all, she remembers, the group seemed to sigh in relief, breathing out years of buried guilt about the disorder. “It’s something in the way I was wired — it’s something I didn’t choose to do,” Heenan says. “It was pretty freeing to know that there could be something else going on.” Years of psychological and behavioral research have helped scientists better understand some signs and triggers of anorexia. But that knowledge hasn’t straightened out the disorder’s tangled roots, or pointed scientists to a therapy that works for everyone. “Anorexia has a high death rate, it’s expensive to treat and people are chronically ill,” says Kaye. © Society for Science & the Public 2000 - 2013
Keyword: Anorexia & Bulimia
Link ID: 18413 - Posted: 07.27.2013
Heidi Ledford A procedure increasingly used to treat obesity by reducing the size of the stomach also reprogrammes the intestines, making them burn sugar faster, a study in diabetic and obese rats has shown. If the results, published today in Science1, hold true in humans, they could explain how gastric bypass surgery improves sugar control in people with diabetes. They could also lead to less invasive ways to produce the same effects. “This opens up the idea that we could take the most effective therapy we have for obesity and diabetes and come up with ways to do it without a scalpel,” says Randy Seeley, an obesity researcher at the University of Cincinnati in Ohio, who was not involved in the work. As rates of obesity and diabetes skyrocket in many countries, physicians and patients are turning to operations that reconfigure the digestive tract so that only a small part of the stomach is used. Such procedures are intended to allow people to feel full after smaller meals, reducing the drive to consume extra calories. But clinical trials in recent years have shown that they can also reduce blood sugar levels in diabetics, even before weight is lost2, 3. “We have to think about this surgery differently,” says Seeley. “It’s not just changing the plumbing, it’s altering how the gut handles glucose.” © 2013 Nature Publishing Group,
Link ID: 18412 - Posted: 07.27.2013
Avoiding temptation works better than relying on willpower alone, a study of brain activity finds. "Struggles with self-control pervade daily life and characterize an array of dysfunctional behaviours, including addiction, overeating, overspending and procrastination," Molly Crockett, a postdoctoral fellow at University College London, and her co-authors said in today's issue of the journal Neuron. "Our research suggests that the most effective way to beat temptations is to avoid facing them in the first place," she said in a release. In the experiment, researchers studied 58 healthy heterosexual males in Cambridge and 20 in Amsterdam. Investigators used functional MRI as part of the study of self-control to explore the neural mechanisms involved. At the beginning of the trial, participants were shown a series of 400 images of women in lingerie or swimwear and were asked to rank them on a scale of zero to 10 on how enjoyable they were. Each man's preferences were then used to present small, short-term rewards or a large reward after a delay. Small rewards were mildly enjoyable erotic pictures and large rewards were extremely enjoyable ones. (The scientists said they could not use money, for example, since subjects could only reap the rewards of money once they left the lab. Food rewards like juice could interfere with the MRI readings.) © CBC 2013
By Scicurious We all know we should get more sleep, we’re just not very good at it. In fact, we’re so BAD at it that 28.3% of us (as of 2007, anyway) got less than 6 hours of sleep per night. Really, are we surprised? After all, there are kids that wake up in the night, stress that keeps us awake, always more things to do, multiple jobs, and only so many hours in the day. But that lack of sleep can have some not so great effects on our bodies. It decreases things like cognitive performance, increases anxiety, and…it’s not good for our waistlines. Sleep loss is associated with higher caloric intake, when you can’t sleep you eat. But does this increased caloric intake translate to weight gain? The biggest positive point of this study on sleep restriction was how LARGE it was. When doing human studies that are not large scale surveys (which usually involve phone calls or mail in or online and therefore are less expensive) it costs a LOT of money to bring some people in to the lab to do nothing but hang out and sleep for a week, especially if you are watching for things like food intake (and controlling what they eat). I’m very pleased that they got these numbers, 225 people! The authors took these 225 people, and brought them into the lab. They got two baseline nights (to see how much they naturally slept), 5 sleep restriction nights, and then another 2 recovery nights. But unfortunately, they did not balance the control and sleep restriction, where they were restricted down to FOUR HOURS a night of sleep (ick). They only had 27 controls out of all of these (people allowed to sleep fully all the nights of the study), the rest were sleep restriction. I have to wonder why they did it this way. While the two original nights and the two recovery nights could in theory serve as a partial control, I don’t think that those would work. After all, if most people are slightly sleep restricted, the original two nights will be recovery as well, and both sets of recovery nights may not be representative of optimal sleep. © 2013 Scientific American
By GINA KOLATA The mice were eating their usual chow and exercising normally, but they were getting fat anyway. The reason: researchers had deleted a gene that acts in the brain and controls how quickly calories are burned. Even though they were consuming exactly the same number of calories as lean mice, they were gaining weight. So far, only one person — a severely obese child — has been found to have a disabling mutation in the same gene. But the discovery of the same effect in mice and in the child — a finding published Wednesday in the journal Science — may help explain why some people put on weight easily while others eat all they want and seem never to gain an ounce. It may also offer clues to a puzzle in the field of obesity: Why do studies find that people gain different amounts of weight while overeating by the same amount? Scientists have long thought explanations for why some people get fat might lie in their genes. They knew body weight was strongly inherited. Years ago, for example, they found that twins reared apart tended to have similar weights and adoptees tended to have weights like their biological parents, not the ones who reared them. As researchers developed tools to look for the actual genes, they found evidence that many — maybe even hundreds — of genes may be involved, stoking appetites, making people voraciously hungry. This rare gene-disabling mutation, though, is intriguing because it seems to explain something different, a propensity to pile on pounds even while eating what should be a normal amount of food. Investigators are now searching for other mutations of the same gene in fat people that may have a similar, but less extreme effect. The hope is that in the long term, understanding how this gene affects weight gain might lead to treatments for obesity that alter the rate at which calories are burned. © 2013 The New York Times Company
By GRETCHEN REYNOLDS Two newly published studies investigate the enticing possibility that we might one day be able to gain the benefits of exercise by downing a pill, rather than by actually sweating. But while some of the research holds out promise for an effective workout pill, there remains the question of whether such a move is wise. The more encouraging of the new studies, which appears this week in Nature Medicine, expands on a major study published last year in Nature. In that study, researchers at the Scripps Research Institute in Jupiter, Fla., reported that a compound they had created and injected into obese mice increased activation of a protein called REV-ERB, which is known to partially control animals’ circadian rhythms and internal biological clocks. The injected animals lost weight, even on a high-fat diet, and improved their cholesterol profiles. Unexpectedly, the treated mice also began using more oxygen throughout the day and expending about 5 percent more energy than untreated mice, even though they were not moving about more than the other animals. In fact, in most cases, they were more physically lazy and inactive than they had been before the injections. The drug, it seemed, was providing them with a workout, minus the effort. Intrigued, the Scripps scientists, in conjunction with researchers from the Pasteur Institute in France and other institutions, set out to see what their compound might be doing inside muscles to provide this ersatz exercise. They knew that their drug increased the potency of the REV-ERB protein, but no one yet knew what REV-ERB actually does in muscles. So they began by developing a strain of mice that could not express very much of the protein in their muscle cells. Copyright 2013 The New York Times Company
Link ID: 18384 - Posted: 07.18.2013
By Sue Shellenbarger It’s easy to be offended when a colleague yawns while you’re talking. But that yawn may not mean what you think. A growing number of researchers believe the purpose of this little-understood behavior is to cool the brain, says a research review published earlier this year in Frontiers in Neuroscience. Changes in climate affect how often people yawn. Researchers in an earlier study asked two groups of pedestrians in Tucson, Ariz., one in early summer and one in the winter. People were asked to look at pictures of people yawning and talk about their own yawning behavior. The participants were nearly twice as likely to yawn when they were surveyed during the winter, when they could inhale cool air to reduce the temperature of the brain, says the study, published in 2011 in Frontiers in Evolutionary Neuroscience. Participants yawned less when surveyed in the early summer, when temperatures outdoors were about the same as the human body. Other studies show yawning increases after people experience heat stress or have a heat pack placed on their foreheads. Yawning also may build empathy within groups. Yawns are seen as contagious, but “catching” a yawn depends on a person’s ability to feel empathy and closeness with the yawner, says a 2013 research review in the International Journal of Applied Basic Medical Research. ©2013 Dow Jones & Company, Inc.
Link ID: 18383 - Posted: 07.18.2013
by Sarah C. P. Williams Researchers think they've hit on why a common obesity gene causes weight gain: Those who carry a version of it don't feel full after eating and take in extra calories. That's because the variant of the FTO gene in question, which one in six individuals carry, leads to higher levels of ghrelin, a hormone involved in mediating appetite and the body's response to food, researchers have discovered. While most studies on FTO have relied on mice, the new work analyzed blood samples and brain scans from humans. "This is a very exciting piece of research," says geneticist Andrew Hattersley of the Peninsula Medical School in Exeter, U.K., who was not involved in the new study. "There is a lot of work that's been done on the mechanism of FTO in animals, but you have to be careful about applying those lessons to people. So it's nice to finally see work done in humans." Hattersley was part of a team that in 2007 reported that people who had one version of the FTO gene, called AA, weighed an average of 3 kilograms more than those with the TT version of the gene. Since then, studies in mice have shown that in everyone, there are high levels of the FTO protein in brain areas that control energy balance. Researchers have also found that animals with the AA version tend to eat more and prefer high-fat food compared with those with the TT version. But why FTO had this effect wasn't known. © 2010 American Association for the Advancement of Science.
Should I stay or should I go? Well, how much food do you have? In some organisms, sexual desire is expressed by leaving, that is, by bidding adieu to a delicious pile of food and wandering off in search of a mate. But not just any mate, a mate with food! Lipton et al., at Albert Einstein College of Medicine, use the “leaving assay” to measure male sexual desire. Their subject is the elegant, rod-like worm, Caenorhabditis elegans.* They start by placing males on their preferred food source; then they measure how often males exit in search of mating partners. You can see the trails they leave in the substrate in this video of C. elegans appropriating Harlem art and culture. How do the researchers know “leaving” is a sex behavior? Context. Leaving a food source occurs only in a sexual context, and the leaving assay is being used to tease apart the threads that control the appetites for food and sex. First, a quick lesson in the fascinating sexuality of C. elegans. Males are not interested in other males, but they search intensely for a mating partner of the other sex. Note that I said “other sex” not “opposite sex.” There are no female C. elegans. Males of this species mate enthusiastically with hermaphrodites. Hermaphrodites can, of course, self-fertilize, but sexual unions between males and hermaphrodites are far more fruitful than selfing. For hermaphrodites, mating with a male will produce more offspring, and for males, hermaphrodites are the only crying game in town.
Keyword: Sexual Behavior
Link ID: 18341 - Posted: 07.03.2013
by Elizabeth Norton Transforming fat cells into calorie-burning machines may sound like the ultimate form of weight control, but the idea is not as far-fetched as it sounds. Unexpectedly, some fat cells directly sense dropping temperatures and release their energy as heat, according to a new study; that ability might be harnessed to treat obesity and diabetes, researchers suggest. Fat is known to help protect animals from the cold—and not only by acting as insulation. In the early 1990s, scientists studying mice discovered that cold temperatures trigger certain fat cells, called brown adipose tissue, to release stored energy in the form of heat—to burn calories, in other words. Researchers have always assumed this mechanism was an indirect response to the physiological stress of cold temperatures, explains cell biologist Bruce Spiegelman of Harvard Medical School, Boston. The activation of brown fat seems to start with sensory neurons throughout the body informing the brain of a drop in temperature. In response the brain sends out norepinephrine, the chief chemical messenger of the sympathetic nervous system, which mobilizes the body to cope with many situations. In experimental animals, stimulating norepinephrine receptors triggered brown adipose tissue to release its energy and generate heat, while animals bred to be missing these receptors were unable to mount the same fat cell response. People also have brown adipose tissue that generates heat when the body is cold. And unlike white fat, which builds up around the abdomen and contributes to many disorders including heart disease and diabetes, this brown fat is found in higher proportions in leaner people and seems to actively protect against diabetes. © 2010 American Association for the Advancement of Science
Link ID: 18334 - Posted: 07.02.2013
By JANE E. BRODY Most people know that obesity can result in serious health problems, yet many of us continue to focus on its cosmetic consequences rather than its risks to health. This distorted view may change now that the American Medical Association has finally labeled obesity a disease, not just a risk factor for other disorders. Last month, the organization recognized that obesity is a verifiable illness that warrants far more attention than physicians, patients and insurers currently give it. The designation may change how aggressively doctors treat obesity, foster the development of new therapies, and lead to better coverage byinsurers. After all, the price of not treating obesity is now in the stratosphere. Obesity-related health conditions cost the nation more than $150 billion and result in an estimated 300,000 premature deaths each year. If the population’s weight gain is not soon capped (or better yet, reversed), experts predict that half of adults in America will be obese by 2040. The A.M.A. has said in effect that it is medicine’s responsibility to provide the knowledge and tools needed to curb this runaway epidemic. On June 19, James Gandolfini, the hefty award-winning actor who portrayed Tony Soprano in “The Sopranos,” died at 51, apparently of a heart attack, while on vacation in Italy. Even if genetics played a role, Mr. Gandolfini’s weight contributed significantly to his risk of sudden cardiac death. Not a week earlier, a 46-year-old member of my family who weighed over 300 pounds died suddenly of what might have been a heart attack while dozing in front of the television. He had long suffered from sleep apnea (a risk factor for sudden death), high blood pressure and severe gout, all results of his extreme weight. Copyright 2013 The New York Times Company
Link ID: 18330 - Posted: 07.01.2013
by Sue Langthorp Losing sleep doesn't just make us hazy and irritable. It can also lead to cardiovascular disease, type 2 diabetes, and a host of other conditions. But catching up on some shuteye may help combat these problems. According to a new study, sleep-deprived men who dozed an extra 2 to 3 hours on the weekend may reduce their risk of developing type 2 diabetes. Researchers led by Peter Liu, an endocrinologist at the Los Angeles Biomedical Research Institute at the Harbor-University of California, Los Angeles, Medical Center, recruited 19 men in good health who, due to their workload, were poor sleepers. The subjects, age 29 on average, had been clocking about 6 hours of shuteye on weeknights for just over 5 years. However, they made the most of their weekends and slept an extra 2.3 hours a night on Friday and Saturday. When selecting the candidates for the trial, the scientists verified their reported schedules using sleep actigraphs, devices worn like wrist watches that record sleep patterns. The men slept in the lab for three nights. Some were allowed to sleep 10 hours without interruption, catching up on the sleep that they had lost earlier in the week. Others slept 10 hours with frequent interruption, and still others slept 6 hours without interruption. All the subjects ate the same diet, so the researchers could normalize their insulin and sugar levels. © 2010 American Association for the Advancement of Science
By NICHOLAS BAKALAR Obesity in adolescents is associated with a range of cardiovascular and other health risks. Now a new study adds one more: hearing loss. Several studies have demonstrated the association of obesity with hearing loss in adults, but now researchers examining records of a nationwide sample of 1,488 boys and girls ages 12 to 19 have found the same association in teenagers. The study appeared online in The Laryngoscope. The researchers controlled for various factors, including poverty, sex, race and previous exposure to loud noises. They found that being at or above the 95th percentile for body mass index — the definition of obesity in teenagers — was independently associated with poorer hearing over all frequencies, and with almost double the risk of low-frequency hearing loss in one ear. They suggest that this may represent an early stage of injury that will later progress to both ears, as it does in adults. The reason for the connection is not known, but the scientists suggest that inflammation induced by obesity may be a factor in organ damage. “It’s quite possible that early intervention could arrest the progression,” said the lead author, Dr. Anil K. Lalwani, a professor of otolaryngology at Columbia University. “This is another reason to lose weight — but not to lose hope.” Copyright 2013 The New York Times Company