Chapter 13. Homeostasis: Active Regulation of the Internal Environment
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By JENNIFER CONLIN It is the moment “The Biggest Loser” viewers anticipate all season. That episode when the finalists emerge, one by one, to bare all — or rather less — to a waiting audience of millions. But on Tuesday night, when Rachel Frederickson, 24, walked onto the studio stage 155 pounds lighter than at the start of Season 15, the reaction was not one of awe, but shock, apparent even on the trainers’ frozen faces. In the few months since Ms. Frederickson, 5 feet 4 inches tall, had left the ranch for her home, her body had radically changed from the athletic 150 pounds she had weighed upon her departure to a gaunt sliver of herself, obvious despite her shimmering silver dress, strappy sandals and big grin. Ms. Frederickson, as the scale would soon reveal, now weighed 105 pounds, and having lost 59.62 percent of her body weight would also be the competition’s winner, making her $250,000 richer. But as confetti dropped all around her, few were celebrating on Twitter. “I feel like Rachel lost too much,” one woman wrote. “I had to turn away.” Another posted, “There needs to be a red line that disqualifies finalists for too much weight loss.” Kai Hibbard, a finalist on Season 3, was at her home in Alaska when another former contestant, whom she declined to name, sent her a message. “Have you seen tonight’s winner?” it read. “NBC is about to have a public-relations nightmare.” When Ms. Hibbard pulled up Ms. Frederickson’s winning photo, she promptly burst into tears. “Rachel doesn’t know what damage she has done to her body and her mind, and sadly she won’t until the spotlight goes away,” said Ms. Hibbard, 35, who seven years ago lost 118 pounds during her competition but has since spoken out publicly against the show’s extreme dieting and exercise regimen. © 2014 The New York Times Company
Ewen Callaway A study in mice and rats suggests that an imbalance in chloride ions during a child's development in the womb could be a factor for autism. Children with autism typically begin showing obvious symptoms, such as trouble making eye contact and slow language development, a year or more after birth. A study in mice and rats now hints that prenatal drug treatment could head off these problems. The findings, reported today in Science1, do not suggest that autism spectrum disorders can be prevented in children. But researchers not involved in the study say that they add support to a controversial clinical trial suggesting that some children with autism benefited from taking a common diuretic medication called bumetanide2. In that trial, a team led by neuroscientist Yehezkel Ben-Ari at the Mediterranean Institute of Neurobiology in Marseille gave 60 children bumetanide or a placebo daily for three months. Children who had less severe forms of autism showed mild improvements in social behaviour after taking the drug, and almost no adverse side effects were observed (see 'Diuretic drug improves symptoms of autism'). But autism researchers greeted the results with caution. Many pointed out that the study did not provide a clear biological mechanism that could explain how the drug improved the symptoms of the disorder. The latest study is an attempt to answer such criticisms by identifying a role for the neurotransmitter GABA. Studies in humans and animals have suggested that GABA, which in healthy people typically inhibits the activity in neurons, is altered in autism and instead activates some brain cells. © 2014 Nature Publishing Group,
Link ID: 19225 - Posted: 02.08.2014
By GRETCHEN REYNOLDS This winter’s frigid temperatures could be having one desirable side effect. They may be revving up your metabolism. Shivering in the cold sparks a series of biochemical reactions deep within the body that alters fat cells and bolsters metabolism, much as formal exercise does, according to a fascinating series of new experiments. The findings intimate that exercise and shivering are related in ways not previously suspected. For the new study, which was published Tuesday in Cell Metabolism, scientists affiliated with several branches of the National Institutes of Health recruited 10 healthy adult men and women and invited them to the lab on three separate occasions. There, the researchers drew blood and obtained small samples of muscle and fat cells. During one lab visit, the volunteers completed a short but very intense session of stationary bicycling, riding as hard as they could until they were exhausted. Then, on another day, they rode the bike at a gentle, easily sustained pace for an hour. Throughout these workouts, the laboratory temperature was maintained at a moderate 65 degrees or so. On their final visit, though, the researchers had each volunteer lie in bed, lightly clad, for 30 minutes as the lab’s temperature dropped from about 75 to a chilly 53 degrees. Monitors were placed on their skin to measure skin and muscle reactions, and by the end of the session, the volunteers were noticeably shivering. After each session, the scientists gathered more blood and other samples and started checking for changes. In particular, they wanted to see what was happening with the volunteers’ white and brown fat. © 2014 The New York Times Company
Link ID: 19204 - Posted: 02.05.2014
By GINA KOLATA For many obese adults, the die was cast by the time they were 5 years old. A major new study of more than 7,000 children has found that a third of children who were overweight in kindergarten were obese by eighth grade. And almost every child who was very obese remained that way. Some obese or overweight kindergartners lost their excess weight, and some children of normal weight got fat over the years. But every year, the chances that a child would slide into or out of being overweight or obese diminished. By age 11, there were few additional changes: Those who were obese or overweight stayed that way, and those whose weight was normal did not become fat. “The main message is that obesity is established very early in life, and that it basically tracks through adolescence to adulthood,” said Ruth Loos, a professor of preventive medicine at the Icahn School of Medicine at Mount Sinai in New York, who was not involved in the study. These results, surprising to many experts, arose from a rare study that tracked children’s body weight for years, from kindergarten through eighth grade. Experts say they may reshape approaches to combating the nation’s obesity epidemic, suggesting that efforts must start much earlier and focus more on the children at greatest risk. The findings, to be published Thursday in The New England Journal of Medicine, do not explain why the effect occurs. Researchers say it may be a combination of genetic predispositions to being heavy and environments that encourage overeating in those prone to it. But the results do provide a possible explanation for why efforts to help children lose weight have often had disappointing results. The steps may have aimed too broadly at all schoolchildren, rather than starting before children enrolled in kindergarten and concentrating on those who were already fat at very young ages. © 2014 The New York Times Company
"Everybody has won and all must have prizes," declared the dodo in Alice in Wonderland when asked to judge the winner of a race around a lake. As judgements go, it is admirably even-handed and optimistic. But in the world of mental health the dodo's decision has come to symbolise a bitter dispute that strikes at the very heart of psychotherapy. The "Dodo Bird Verdict", first suggested in the 1930s by the American psychologist Saul Rosenzweig, proposes that the many and various forms of psychological therapy are all equally effective. It makes no difference whether, for example, a person is being treated with techniques drawn from psychoanalysis, neurolinguistic programming, or cognitive behaviour therapy (CBT). What really helps a patient to recover are straightforward factors such as the opportunity to discuss their worries with a skilled and sympathetic therapist or the degree to which they are prepared to engage with the treatment. Understandably, the Dodo Bird Verdict has ruffled many feathers within the profession, and provoked a slew of studies aiming to corroborate or disprove the idea. Are some types of psychotherapy really more effective than others for particular conditions? There is plentiful data to suggest that the answer to that question – contrary to Rosenzweig's theory – is "yes". But that data tends to come from research conducted by proponents of the ostensibly superior therapy, leaving sceptics to conclude that their conclusions are not impartial. This makes the results of a study of treatments for the eating disorder bulimia nervosa, published this month in the American Journal of Psychiatry, all the more convincing. Bulimia is characterised by binge eating, followed by attempts to compensate by making oneself vomit, taking laxatives or diuretics (water tablets), fasting, and/or exercising frantically. Underlying this behaviour is an intense concern – an obsession, even – with body shape and weight. © 2014 Guardian News
Keyword: Anorexia & Bulimia
Link ID: 19164 - Posted: 01.25.2014
By Eric Niiler, It may come as a surprise that Finland — one of the least polluted, wealthiest countries, where average life expectancy is among the world’s highest — has the highest rate of Type 1 diabetes. Each year, there are about 58 cases diagnosed per 100,000 children; in the United States there are 24 cases per 100,000, according to the International Diabetes Federation. Some researchers suspect there may be a connection between Finland’s cleanliness and the incidence of the disease there. They are investigating whether the lack of exposure to a specific group of bacteria found in the intestine may be causing weaker immune systems in Finnish children, making them more susceptible to Type 1 diabetes. This so-called hygiene hypothesis — that cleaner living can result in a weaker immune system — has also been linked to ailments such as asthma, allergies and other autoimmune diseases. “We are working along the idea that we have a trigger which most likely is an infectious agent,” said Mikael Knip, a professor of pediatrics at the University of Helsinki who has been studying diabetes for 30 years. “There is an association between such infections and appearance of antibodies.” Just as there are microbes that trigger the disease, Knip says there are also some bacterial or viral infections that, if they occur at an early age, can protect a young child from developing Type 1 diabetes. Type 1 diabetes, which affects approximately 37 million people worldwide, is an autoimmune disease in which the body does not produce sufficient insulin, a hormone needed to break down sugars. Typically diagnosed in children, teens and young adults, the disease can eventually damage the eyes and organs such as the kidneys, and it increases the likelihood of stroke and heart failure. © 1996-2014 The Washington Post
Overweight and obese adults who drink diet pop also tend to eat more calories each day from food, a finding that hints at how relying on diet beverages for weight loss could be a mistake. In this week’s issue of the American Journal of Public Health, researchers from Johns Hopkins Bloomberg School of Public Health in Baltimore analyzed U.S. survey data for 24,000 people from 1999 to 2010. They looked for patterns in beverage consumption and calories. The sweet taste of beverages, whether from sugar or artificial sweeteners, seems to enhance our appetite and encourage cravings for sugar. (Rob Carr/Associated Press) Overweight consumers of diet beverages took in 1,965 in food calories a day compared with 1,874 calories among those in the same weight class who drank beverages sweetened with sugar, such as non-diet soda, sports drinks, fruit drinks and sweetened tea. As people increasingly switch to diet beverages, the focus on reducing sugar from drinks might not be enough to lose weight in the long term, the researchers concluded. "The switch from a sugary beverage to a diet beverage should be coupled with other changes in the diet, particularly reducing snacks," suggested lead author Sara Bleich. In the study, snacking patterns were generally the same between diet and sugary beverage drinkers. The researchers said the finding is consistent with evidence that the sweet taste of beverages, whether from sugar or artificial sweeteners, enhances our appetite and encourage cravings for sugar. © CBC 2014
Link ID: 19148 - Posted: 01.18.2014
By ANAHAD O'CONNOR Scientists call it the obesity paradox, the notion that being overweight or moderately obese lowers the risk of an early death. They have documented the phenomenon in large population studies and in groups of patients with chronic diseases like hypertension and Type 2 diabetes. But now a new report, published on Wednesday in The New England Journal of Medicine, is calling the obesity paradox into question, at least for patients with Type 2 diabetes. The study, of nearly 12,000 people with the disease, found that there was no survival advantage for those who had a body mass index that put them in the overweight or obese categories. Instead, the researchers found that the diabetics with the lowest mortality rate were those who were considered normal weight. The study is among the largest to examine the obesity paradox among people with Type 2 diabetes, an illness that afflicts more than 25 million Americans. The authors argue that previous studies showing a protective effect of a high B.M.I. among diabetics were flawed because they were too small or failed to account for factors like smoking or undiagnosed illnesses that can contribute to low body weight but a shorter life span as well. The new study found that when smoking and other factors that can contribute to weight loss were accounted for, people in the highest B.M.I. groups had higher mortality rates. “I think the case is not necessarily closed,” said Deirdre K. Tobias, the lead author of the paper and a research fellow at the Harvard School of Public Health. “But at this point, there is no reason to believe that being overweight or obese would be protective for people with diabetes.” © 2014 The New York Times Company
Link ID: 19138 - Posted: 01.16.2014
By ANDREW POLLACK Launch media viewer Kristin Tremblay helps make dinner at home in Gainesville, Fla. She has a disorder that makes her uncontrollably hungry. Rob C. Witzel for The New York Times Lisa Tremblay still recalls in horror the time her daughter Kristin pulled a hot dog crawling with ants from the garbage at a cookout and prepared to swallow it. Kristin has a rare genetic abnormality that gives her an incessant, uncontrollable hunger. Some people with the condition, called Prader-Willi syndrome, will eat until their stomach ruptures and they die. And, not surprisingly, many are obese. “She’s eaten dog food. She’s eaten cat food,” said Ms. Tremblay, who lives in Nokomis, Fla. When Kristin, now 28, was a child, neighbors once called social welfare authorities, thinking Kristin was not being fed because she complained of being hungry so much. Once an obscure and neglected disease, Prader-Willi is starting to attract more attention from scientists and pharmaceutical companies for a simple reason: It may shed some light on the much broader public health problems of overeating and obesity. “These are remarkable human models of severe obesity,” said Dr. Steven B. Heymsfield, a professor and former executive director of the Pennington Biomedical Research Center in Baton Rouge, La. “When we discover the underlying mechanism of these very rare disorders, they will shed light on garden-variety obesity.” One drug being developed to help obese people lose weight has shown some preliminary signs of success in patients with Prader-Willi. The drug, beloranib, is believed to work by reducing fat synthesis and increasing fat use. In a small trial, it reduced weight and body fat and lowered the food-seeking urge, according to the drug’s developer, Zafgen. © 2014 The New York Times Company
By Stephen L. Macknik Hypoglycemia occurs when your blood sugar gets dangerously low, resulting in sweating, the feeling of weakness and dysphoria (the “don’t touch me” feeling you have when you’re sick and nauseous, possibly unconscious, as with the flu), and a variety of other symptoms. You basically go into a state similar to shock. The principal problem, however, arises from low blood sugar supply to the brain, resulting in impairment of function. It’s a common problem in diabetic non-compliance (not eating low-carbohydrate foods while diabetic), which is especially prevalent in the poor. SABRINA TAVERNISE, of The New York Times reported on a new study in the journal Health Affairs, by Seligman and colleagues of the University of California, San Francisco, in which they analyzed the prevalence of hypoglycemia in low income populations at risk for hypoglycemia, as a function of time since the patients’ households’ last pay day. They found that hypoglycemia increases at the end of a pay cycle in low-income diabetics. They thus concluded that low-income diabetic patients have low access to food at the end of the month, resulting in frank starvation and thus low blood sugar. I find this to be an unlikely scenario. It’s not that I don’t believe that low-income is tied to diabetes and hypoglycemia at the end of the pay cycle. I do believe it, and the Centers for Disease Control have determined that 8% of the population has diabetes, and that the burden is carried by low-income families. So I think the main effect, increased hypoglycemia in the poor at the end of their pay cycle, is correct (and Ms. Tavernise reports that experts in the field are happy with the methods, so I’m happy with them too as a non-expert in this field). © 2014 Scientific American
Link ID: 19114 - Posted: 01.09.2014
Just in time for all those New Year’s resolutions to exercise more, scientists have a better idea of how the body turns pain into gain. Exertion stimulates muscles to release a molecule that modifies fat cells, turning them into calorie-burning machines, a research team has found. Exercise works the muscles but affects cells throughout the body, even in the brain. An important player in this process is a protein called PGC-1α. In exercising muscles, it activates genes that ramp up energy use. But its impact extends beyond these tissues. The protein somehow indirectly prompts, for example, white fat—the energy-storing variety that pads our hips and stomachs—to switch on genes that are characteristic of brown fat, a form that burns calories. PGC-1α doesn’t travel outside muscle cells, so researchers aren’t sure how its influence spreads, however. By sifting through the secretions of PGC-1α-making muscle cells, Robert Gerszten of Harvard Medical School in Boston and colleagues have nabbed one molecule that might be doing the protein’s bidding: β-aminoisobutyric acid (BAIBA). They found that BAIBA induces white fat cells to become more like brown fat cells, altering their gene activity patterns. And it stimulates other cell types, stoking fat metabolism in the liver, the team also reveals today in Cell Metabolism. These effects may translate into a healthier metabolism. When mice lapped up water laced with the molecule, the rodents lost weight and were better at absorbing glucose. © 2014 American Association for the Advancement of Science
By SABRINA TAVERNISE Poor people with diabetes are significantly more likely to go to the hospital for dangerously low blood sugar at the end of the month when food budgets are tight than at the beginning of the month, a new study has found. Researchers found no increase in such hospitalizations among higher-income people for the condition known as hypoglycemia, suggesting that poverty and exhausted food budgets may be a reason for the increased health risk. Hypoglycemia occurs when people with diabetes have not had enough to eat, but continue taking medications for the disease. To control diabetes, patients need to keep their blood sugar within a narrow band. Levels that are too low or too high (known as hyperglycemia) can be dangerous. Researchers found a clear pattern among low-income people: Hospital admissions for hypoglycemia were 27 percent higher at the end of the month than at the beginning. Researchers said they could not prove that the patients’ economic circumstances were the reason for the admission, but the two things were highly correlated. The study, published online Monday in the journal Health Affairs, comes as Congress continues to debate legislation that includes the food stamp program for poor Americans. House Republicans are advocating $40 billion in cuts to the program, a step that Democrats oppose. About 25 million Americans, or 8 percent of the population, have diabetes, according to the Centers for Disease Control and Prevention. The poor are disproportionately affected. The United States spends more than $100 billion a year treating people with the disease, the agency estimates. © 2014 The New York Times Company
Link ID: 19103 - Posted: 01.07.2014
By NICHOLAS BAKALAR Are there good scientific studies that show that drinking sugar-sweetened soda increases the risk for obesity? The answer may vary depending on who is paying for the study. Researchers examined 17 large reviews of the subject (one review assessed results for adults and children separately, so there were 18 sets of study conclusions). Six of the studies reported receiving funds from industry groups, including Coca-Cola, PepsiCo, the American Beverage Association and others. The other 12 reviews claimed no conflicts of interest. The analysis appears in the December issue of PLOS Medicine. Among the reviews with no conflicts of interest, 10 of 12, or 83.3 percent, reported that sugary drinks were directly associated with weight gain or obesity. The conclusions of studies supported by industry were a mirror image: five of six — the same 83.3 percent — reported that there was insufficient evidence to draw a conclusion. “I wouldn’t say that industry participation alone is enough to dismiss the study’s results in the whole of nutrition research,” said the lead author, Maira Bes-Rastrollo, a professor of preventive medicine at the University of Navarra in Spain. “But I think that the general public and the scientific community should be aware that the food industry has vested interests that may influence their conclusions.” Copyright 2014 The New York Times Company
Link ID: 19099 - Posted: 01.06.2014
JoNel Aleccia NBC News Surgery to remove a brain tumor two years ago has left a 12-year-old Texas girl with a heartbreaking condition that makes her gain massive amounts of weight — even though her body thinks it’s starving. Doctors say a gastric bypass operation is the only thing that can help Alexis Shapiro, who is 4-foot-7 and weighs 198 pounds. But the U.S. military, which provides her family’s health insurance, says it won’t pay for the $50,000 weight-loss procedure because she’s too young. “Our reviewers have denied your request for Roux-En-Y Gastric Bypass,” reads the rejection notice sent this month. Alexis’ parents — and her doctor — are protesting the decision from insurer TRICARE, which they say sentences the child to a fate of dangerous health problems and social isolation caused by hypothalamic obesity, which is packing on at least 2 pounds every week. “It just keeps going up and up,” said her mother, Jenny Shapiro, 34, of Cibolo, Texas. “She desperately needs this. I feel like she will die if she does not get this surgery.” In just the past three months, Alexis was hospitalized for a kidney infection and developed Type 2 diabetes that requires nightly insulin injections, both related to her growing girth. Dr. Thomas H. Inge, a Cincinnati expert in pediatric obesity who is treating Alexis, acknowledged that there have been few cases like hers. But he said surgery may be the only way to stop weight gain that could top out at 400 pounds — and to cut the brain cravings that make Alexis want to eat an entire jar of peanut butter at one sitting.
Link ID: 19076 - Posted: 12.28.2013
By MICHAEL MOSS WEST LAFAYETTE, Ind. — “Here are the nuts,” said Drew Sayer, a graduate student in nutrition science, before shoving me into the M.R.I. machine, flat on my back. “Chew them. Swallow them. And don’t move your head.” I moved my head, which blurred the resulting images. But if all goes well in the coming weeks, researchers here at Purdue University will have stacks of brain scans with crystal-clear views inside the minds of their test subjects — while they were eating nuts. These images could help answer a timely question: Do nuts really merit the hype they’ve been getting as a guilt-free indulgence? The reports about their many benefits have come thick and fast: studies finding that people who eat nuts (tree nuts like cashews, almonds and pistachios, along with their legume pal, the peanut) live longer and healthier lives, with less risk of chronic ailments like heart disease, respiratory problems and Type 2 diabetes. But perhaps the most startling news is that nuts may help in maintaining a healthy weight. Research has found that people can snack on modest amounts of them without gaining pounds, and that nuts can even help in slimming down. This dieting power is particularly hard to fathom when you consider that nuts pack 160 to 200 calories in each tiny ounce, not even a handful. And most of those calories come from fat. Ounce for ounce, cashews and pecans and walnuts are loaded with more calories than many of the processed foods being blamed for the surge in obesity. In the conventional wisdom, a dieter’s best friends are watery foods like celery and carrot sticks. One of the country’s leading nutrition scientists, Richard Mattes of Purdue, has been exploring this seeming paradox and has some intriguing, if still uncertain, findings. His current work on nuts is being funded by a marketing group, the Almond Board of California, which would normally raise concerns about bias. But Dr. Mattes has a record of biting the hands that feed science, and challenging presumptions about nutrition. © 2013 The New York Times Company
Link ID: 19046 - Posted: 12.18.2013
by Bethany Brookshire “You are what you eat.” We’ve all heard that one. What we eat can affect our growth, life span and whether we develop disease. These days, we know that we also are what our mother eats. Or rather, what our mothers ate while we were in the womb. But are we also what our father eats? A new study shows that in mice, a dietary deficiency in dad can be a big downer for baby. The dietary staple in the study was folic acid, or folate. Folate is one of the B vitamins and is found in dark leafy greens (eat your kale!) and has even been added to some foods like cereals. It is particularly essential to get in the diet because we cannot synthesize it on our own. And it plays roles in DNA repair and DNA synthesis, as well as methylation of DNA. It’s particularly important during development. Without adequate folate, developing fetuses are prone to neural tube disorders, such as spina bifida. Some of the neural tube disorders caused by folate deficiency could result from breaks in the DNA itself. But folic acid is also important in the epigenome. Epigenetics is a mechanism that allows cells to change how genes are used without changing the genes themselves. Instead of altering the DNA itself, epigenetic alterations put chemical “marks” or “notes” —methyl or acetyl groups — on the DNA and the proteins associated with it. The marks can either make a gene more accessible (acetylation) or less accessible (methylation), making it more or less likely to be made into a protein. This means that each cell type can have a different epigenome, allowing a neuron to function differently than a muscle cell, even though they contain the same DNA. Folate affects DNA synthesis, but it can also affect DNA methylation. In fact, DNA methylation requires the presence of folate. So low folate could affect whether genes are turned off or on and by how much. In a developing fetus, that could contribute to developmental problems. © Society for Science & the Public 2000 - 2013.
Many physicians and parents report that their autistic children have unusually severe gastrointestinal problems, such as chronic constipation or diarrhea. These observations have led some researchers to speculate that an ailing gut contributes to the disorder in some cases, but scientific data has been lacking. Now, a provocative study claims that a probiotic treatment for gastrointestinal issues can reduce autismlike symptoms in mice and suggests that this treatment could work for humans, too. The reported incidence of gut maladies in people with autism varies wildly between published studies—from zero to more than 80%—making it difficult to establish just how commonly the two conditions go together, says principal investigator Sarkis Mazmanian, a microbiologist at the California Institute of Technology (Caltech) in Pasadena. Overall, however, the evidence seems to point toward a connection. Last year, for example, a Centers for Disease Control and Prevention study of thousands of children with developmental disabilities found that kids with autism were twice as likely as children with other types of disorders to have frequent diarrhea or colitis, an inflammation of the large intestine. For many years, Mazmanian and his and colleagues have been studying the effects of a nontoxic strain of the bacterium Bacteroides fragilis on diseases such as Crohn's disease, which causes intestinal inflammation and allows potentially harmful substances that should pass out of the body to leak through junctions between cells that are normally tight. Although the researchers don’t understand the mechanism, the bacterium appears to restore the damaged gut, possibly by helping close these gaps. © 2013 American Association for the Advancement of Science.
Link ID: 19009 - Posted: 12.06.2013
By NICHOLAS BAKALAR A high body mass and a large waist are both associated with self-reported hearing loss, a new study has found. Researchers used data from a 20-year prospective study of 68,421 women who were25 to 42 years old at the start. After controlling for age, smoking, diabetes, hypertension and other factors, they found that the higher the body mass index, the greater the risk for hearing loss. Compared with women with a B.M.I. under 25, those with an index of 25 to 29 had an 8 percent increased risk. The numbers kept going up in tandem: 11 percent for 30 to 34, 16 percent for 35 to 39 and 19 percent for those above 40. The increasing risk associated with larger waist circumference followed a similar pattern. The study, published in the December issue of The American Journal of Medicine, found that moderate physical activity — as little as four hours of walking a week — also reduced the risk for hearing loss. Researchers found no further advantage in more vigorous exercise. The lead author, Dr. Sharon G. Curhan, a clinical researcher at Brigham and Women’s Hospital in Boston, suggested that obesity might compromise blood flow to the inner ear, and that exercise might improve it, which could explain the associations. “Hearing loss may not be an inevitable part of growing older,” she said. “There may be things we can do to prevent it.” Copyright 2013 The New York Times Company
By KRISTIN WARTMAN THE solution to one of America’s most vexing problems — our soaring rates of obesity and diet-related diseases — may have its roots in early childhood, and even in utero. Researchers at the Monell Chemical Senses Center, a nonprofit research organization in Philadelphia, have found that babies born to mothers who eat a diverse and varied diet while pregnant and breast-feeding are more open to a wide range of flavors. They’ve also found that babies who follow that diet after weaning carry those preferences into childhood and adulthood. Researchers believe that the taste preferences that develop at crucial periods in infancy have lasting effects for life. In fact, changing food preferences beyond toddlerhood appears to be extremely difficult. “What’s really interesting about children is, the preferences they form during the first years of life actually predict what they’ll eat later,” said Julie Mennella, a biopsychologist and researcher at the Monell Center. “Dietary patterns track from early to later childhood but once they are formed, once they get older, it’s really difficult to change — witness how hard it is to change the adult. You can, but it’s just harder. Where you start, is where you end up.” This may have profound implications for the future health of Americans. With some 70 percent of the United States population now overweight or obese and chronic diseases skyrocketing, many parents who are eating a diet high in processed, refined foods are feeding their babies as they feed themselves, and could be setting their children up for a lifetime of preferences for a narrow range of flavors. The Monell researchers have identified several sensitive periods for taste preference development. One is before three and a half months of age, which makes what the mother eats while pregnant and breast-feeding so important. “It’s our fundamental belief that during evolution, we as humans are exposed to flavors both in utero and via mother’s milk that are signals of things that will be in our diets as we grow up and learn about what flavors are acceptable based on those experiences,” said Gary Beauchamp, the director of the Monell Center. © 2013 The New York Times Company
by Jessica Griggs HAVING type 2 diabetes may mean you are already on the path to Alzheimer's. This startling claim comes from a study linking the two diseases more intimately than ever before. There is some good news: the same research also offers a way to reverse memory problems associated with diabetes – albeit in rats – which may hint at a new treatment for Alzheimer's. "Perhaps you should use Alzheimer's drugs at the diabetes stage to prevent cognitive impairment in the first place," says Ewan McNay from the University at Albany in New York. Alzheimer's cost the US $130 billion in 2011 alone. One of the biggest risk factors is having type 2 diabetes. This kind of diabetes occurs when liver, muscle and fat cells stop responding efficiently to insulin, the hormone that tells them to absorb glucose from the blood. The illness is usually triggered by eating too many sugary and high-fat foods that cause insulin to spike, desensitising cells to its presence. As well as causing obesity, insulin resistance can also lead to cognitive problems such as memory loss and confusion. In 2005, a study by Susanne de la Monte's group at Brown University in Providence, Rhode Island, identified a reason why people with type 2 diabetes had a higher risk of developing Alzheimer's. In this kind of dementia, the hippocampus, a part of the brain involved in learning and memory, seemed to be insensitive to insulin. Not only could your liver, muscle and fat cells be "diabetic" but so it seemed, could your brain. © Copyright Reed Business Information Ltd.