Researchers with McGill University have reportedly identified a genetic mutation linked to the development of mood disorders and obesity in humans.Carl Ernst, et al., “Highly Penetrant Alterations of a Critical Region Including BDNF in Human Psychopathology and Obesity,”Archives of General Psychiatry,October 2012. After screening more than 35,000 people referred for genetic testing and comparing the results with data from approximately 30,000 control subjects, scientists found five participants with a rare genomic deletion of brain-derived neurotrophic factor (BDNF), “a nervous system growth factor that plays a critical role in brain development.” These participants all exhibited obesity and “mild-moderate intellectual impairment” as well as a mood disorder. “The consensus phenotype for individuals with a deletion in BDNF suggests that young children are hyperactive and have an intolerance to change. As subjects age, they likely develop more pronounced anxiety and mood disorders, exemplified by the 16-year-old and 21-year-old subjects with major depressive disorder and…
Category Archives Scientific/Technical Items
A recent study examining the shared neurobiological substrates of obesity and addiction has concluded that “there are several identifiable circuits in the brain, whose dysfunctions uncover real and clinically meaningful parallels between the two disorders.” N.H. Volkow, et al., “Obesity and addiction: neurobiological overlaps,” Obesity Reviews, September 2012. According to the study’s authors, “Drugs of abuse tap into the neuronal mechanisms that modulate the motivation to consume food, thus, it is not surprising that there is an overlap in the neuronal mechanisms implicated in the loss of control and overconsumption of food intake seen in obesity and in the compulsive intake of drugs seen in addiction.” In particular, the study considers brain dopamine (DA) pathways and their role in both obesity and addiction, cautioning that the current debate over “food addiction” often oversimplifies behavioral patterns involving environmental and biological factors. As a result, the authors seek to sidestep the debate by…
A recent animal study has reportedly identified a new mechanism by which the brain increases the desire to overconsume sweet and fatty treats like chocolate. Alexandra DiFeliceantonio, et al., “Enkephalin Surges in Dosal Neostriatum as a Signal to Eat,” Current Biology, October 2012. Relying on advanced opioid microdialysis techniques to detect extracellular levels of a neurotransmitter called enkephalin, University of Michigan researchers injected a drug into the neostriatum of rats to stimulate the mu opioid receptors before the animals were permitted to eat M&M candies. The results evidently showed that mu opioid stimulation “potently enhanced consumption of palatable M&M chocolates,” with injected rats “more than doubling total M&M intake.” In addition, the authors’ microdialysis study of the same brain region, which has primarily been linked to movement, purportedly revealed that naturally occurring enkephalin levels “rose to 150% of baseline when the rats were suddenly allowed to eat chocolates.” According to…
A recent study has allegedly linked low doses of bisphenol A (BPA) to reproductive abnormalities in rhesus monkeys. Patricia A. Hunt, et al., “Bisphenol A alters early oogenesis and follicle formation in the fetal ovary of the rhesus monkey,” Proceedings of the National Academy of Sciences, September 2012. Seeking to determine whether BPA exposure “could influence [] reproductive longevity and success,” researchers from University of California, Davis, and Washington State University (WSU) sought to approximate human exposure levels by administering BPA to gestating rhesus monkeys via one daily oral dose or a continuous subdermal implant. Their results evidently showed that the egg cell failed to divide properly in both groups of monkeys exposed to BPA, with those in the continuous-dosing group exhibiting further complications in the third trimester as fetal eggs “were not packaged appropriately in follicles, structures in which they develop,” according to a September 24, 2012, WSU press release.…
A recent commentary published in the International Journal of Obesity has dubbed high-fructose corn syrup (HFCS) “one of the most misunderstood ingredients,” arguing that studies linking the sweetener’s use to increasing obesity rates tend to rely on temporal associations, “an ecologic fallacy in which group data are extrapolated to individuals.” D.M. Klurfeld et al., “Lack of evidence for high fructose corn syrup as the cause of the obesity epidemic,” International Journal of Obesity, September 2012. In particular, the article’s authors claim that not only did earlier hypotheses fuel misconceptions about “the metabolism and health effects of HFCS,” but more recent research has failed to identify a mechanism by which HFCS affects the body differently than sucrose, “the leading source of fructose in the American diet.” They also note that obesity and diabetes rates have not declined even as HFCS consumption has decreased and that these rates have persisted in areas…
Researchers with the University of Missouri-Kansas City and the University of Kansas Medical Center have published a study claiming that children’s brain scans registered increased activation in the orbitofrontal precortex and inferior prefrontal cortex when the subjects were shown familiar food logos. Amanda Bruce, et al., “Branding and a child’s brain: an fMRI study of neural responses to logos,” Social Cognitive and Affective Neuroscience, September 2012. The study’s authors apparently used functional magnetic resonance imaging (fMRI) with 17 healthy-weight children to gauge their neural reactions to 60 food and 60 non-food logos as opposed to a baseline image created to approximate the logos’ visual properties of color composition and brightness. “Food logos compared to baseline were associated with increased activation in orbitofrontal cortex and inferior prefrontal cortex,” concluded the report. “Compared to nonfood logos, food logos elicited increased activation in the posterior cingulate cortex. Results confirmed that food logos activate…
The New England Journal of Medicine (NEJM) has published a series of studies and commentary on the purported health effects of consuming sugar-sweetened beverages. The American Beverage Association issued a statement contending that studies focusing “solely on sugar-sweetened beverages” as an alleged cause of obesity “or any single source of calories, do nothing meaningful to help address this serious issue. The fact remains: sugar-sweetened beverages are not driving obesity. By every measure, sugar-sweetened beverages play a small and declining role in the American diet.” The studies included Janne de Ruyter, et al., “A Trial of Sugar-free or Sugar-Sweetened Beverages and Body Weight in Children,” (concluding, “[m]asked replacement of sugar-containing beverages with noncaloric beverages reduced weight gain and fat accumulation in normal-weight children.”); Cara Ebbeling, et al., “A Randomized Trial of Sugar-Sweetened Beverages and Adolescent Body Weight,” (concluding, “[a]mong overweight and obese adolescents, the increase in [body mass index] was smaller…
A recent study has purportedly identified an association between urinary bisphenol A (BPA) concentration and obesity in children and adolescents. Leonardo Trasande, et al., “Association Between Urinary Bisphenol A Concentration and Obesity Prevalence in Children and Adolescents,” Journal of the American Medical Association, September 2012. Relying on data from 2,838 participants ages 6-19 years who were enrolled in the 2003-2008 National Health and Nutrition Examination Surveys, researchers evidently found that urinary BPA concentration “was significantly associated with obesity.” In particular, the study reported that urinary BPA values in the second, third and fourth quartiles showed “a substantial elevation in the odds of obesity” when compared with first-quartile values, with “an adjusted prevalence of obesity of 22.3%... among children in the highest quartile, compared with a 10.3% prevalence…among those in the lowest quartile.” “To our knowledge, this is the first report of an association of an environmental chemical exposure with childhood obesity in…
U.S. Centers for Disease Control and Prevention (CDC) researchers recently published a study finding that sodium intake among U.S. children and adolescents “is positively associated” with systolic blood pressure (SBP) and risk for pre-high blood pressure and high blood pressure (pre-HBP/HBP). Quanhe Yang, et al., “Sodium Intake and Blood Pressure Among US Children and Adolescents,” Pediatrics, October 2012. According to the study, which used 24-hour dietary recalls to estimate the sodium intake of 6,235 children ages 8-18 years, the subjects consumed an average of 3,387 milligrams of sodium daily. The results also apparently indicated that the associations between sodium intake and increased SBP and risk for pre-HBP/HBP “may be stronger” among the 37 percent of participants who were overweight or obese than among those who were not. While in normal-weight children every 1,000 mg extra of sodium evidently corresponded with a one-point rise in SBP, in obese or overweight children…
The Journal of the American Medical Association (JAMA) has devoted its latest issue to articles focusing on obesity. Among them is a commentary authored by Thomas Farley, who is affiliated with New York City’s Department of Health and Mental Hygiene, which recently adopted a prohibition on sugar-sweetened beverages larger than 16 ounces. Titled “The Role of Government in Preventing Excess Calorie Consumption,” the opinion piece calls for “governments to regulate food products that harm the most people, simultaneously encourage food companies to voluntarily produce and market healthful products, and then provide information to consumers in ways that facilitate their choosing healthful products.” He argues that New York City has taken this approach and compares it to the city’s action on smoking, which has purportedly led to a 35 percent decline in smoking since 2002. Farley claims that industry opposes New York City’s portion rule by portraying it as a “limit…
