(Press-News.org) An international team of researchers' study of the spatial patterns of the spread of obesity suggests America's bulging waistlines may have more to do with collective behavior than genetics or individual choices. The team, led by City College of New York physicist Hernán Makse, found correlations between the epidemic's geography and food marketing and distribution patterns.
"We found there is a relationship between the prevalence of obesity and the growth of the supermarket economy," Professor Makse said. "While we can't claim causality because we don't know whether obesity is driven by market forces or vice versa, the obesity epidemic can't be solved by focus on individual behavior."
The teams findings, published online this week in Scientific Reports, come as a policymakers are starting to address the role of environmental factors in obesity. For example, in New York Mayor Michael Bloomberg wants to limit serving sizes of soda sweetened with sugar to 16 ounces as a way to combat obesity.
The World Health Organization considers obesity a global epidemic similar to cancer or diabetes. It is a non-communicable disease for which no prevention strategy has been able to contain the spread.
Because obesity is related to increased calorie intake and physical inactivity, prevention has focused on changing individuals' behaviors. However, prevalence of non-communicable diseases shows spatial clustering, and the spread of obesity has shown "high susceptibility to social pressure and global economic drivers."
Professor Makse and his colleagues hypothesized that these earlier findings suggest collective behavior plays a more significant role in the spread of the epidemic than individual factors such as genetics and lifestyle choices. To study collective behavior's role, they implemented a statistical clustering analysis based on the physics on the critical phenomena.
Using county-level microdata provided by the U.S. Centers for Disease Control Behavior Risk Factor Surveillance Systems for 2004 through 2008, they investigated spatial correlations for specific years. Over that time span, the pattern of the spreading of the epidemic, which has Greene County, Ala., as its epicenter, has shown that two clusters spanning distances of 1,000 kilometers have emerged; one along the Appalachian Mountains, the second in the lower Mississippi River valley.
The spatial map of obesity prevalence in the United States shows that neighboring areas tend to have similar percentages of their populations considered obese, i.e. have a body mass index greater than or equal to 30. Such areas are considered obesity clusters, and their spread can be seen in the maps from 2004 to 2008.
To assess the properties of these spatial arrangements, the researchers calculated an equal-time, two-point correlation function that measured the influence of a set of characteristics in one county on another county at a given distance. The characteristics studied were population density, prevalence of adult obesity and diabetes, cancer mortality rates and economic activity.
The researchers said the form of the correlations in obesity were reminiscent of those in physical systems at a critical point of second-order phase transition. Such systems are uncorrelated and characterized by short-range vanishing fluctuations when they are not at a critical stage.
However, at critical points long-range correlations appear, and these may signal the emergence of strong critical fluctuations in the spreading of obesity and diabetes. Consequently, they concluded the clustering patterns found in obesity were the result of "collective behavior, which may not merely be the consequence of fluctuations in individual habits."
Professor Makse and his colleagues believe the correlations of fluctuations in the prevalence of obesity may be linked to demographic and economic variables. To test this hypothesis, they compared the spatial characteristics of industries associated with food production and sales, e.g. supermarkets, food and beverage stores, restaurants and bars, to other sectors of the economy.
Their analysis of spatial fluctuations in food economic activity gave rise to the same anomalous values as obesity and diabetes. Areas with above-average concentrations of food-related businesses had high-than-normal prevalence of obesity and diabetes.
In future studies, Professor Makse plans to apply physics concepts to measure the spread of cancer and diabetes. "The basic idea is that if a non-communicable disease is spreading like a virus, then environmental factors have to be at work," he said. "If only genetics determined obesity, we wouldn't have seen the correlations."
INFORMATION:
Collaborating authors were: Lazaros K. Gallos of the Levich Institute and Department of Physics at City College; Pablo Barttfeld and Mariano Sigman of Integrative Neuroscience Laboratory and Department of Physics at Universidad de Buenos Aires (Argentina) and Shlomo Havlin of the Minerva Center and Department of Physics at Bar-Ilan University (Israel). Professor Makse and Dr. Gallos are supported by a National Science Foundation grant.
On the Internet
Full article on Scientific Reports web site
http://www.nature.com/srep/2012/120614/srep00454/full/srep00454.html
Professor Makse's web page
http://lisgi1.engr.ccny.cuny.edu/~makse/
Levich Institute
http://www-levich.engr.ccny.cuny.edu/
City College of New York Physics Department
http://www1.ccny.cuny.edu/prospective/science/physics/
END
CHAMPAIGN, Ill. — Experienced anglers know that choppy waters make for difficult fishing, so they try not to rock the boat. Thanks to a new microscopy technique, cell biology researchers can heed that same advice.
University of Illinois researchers developed a method they call "trolling AFM," which allows them to study soft biological samples in liquid with high resolution and high quality. Led by mechanical science and engineering professor Min-Feng Yu, the group published its findings in the journal Nanotechnology.
"We developed a highly sensitive method for high-resolution ...
(Boston) – A recent study conducted by researchers at Boston Medical Center (BMC) shows that patients receiving "take home" methadone maintenance treatment (MMT) were less likely to be admitted to the hospital as compared to those not receiving take home doses. The findings, which are published online in the Journal of Addiction Medicine, demonstrate the potential benefits of successful addiction treatment, including better overall health and decreased health care utilization.
This research was led by Alexander Walley, MD, MSc, physician in general internal medicine at ...
Nine out of 10 Californians under the age of 65 will be enrolled in health insurance programs as a result of the Patient Protection and Affordable Care Act (ACA), according to a joint study by the UC Berkeley Center for Labor Research and Education and the UCLA Center for Health Policy Research.
Between 1.8 million and 2.7 million previously uninsured Californians will gain coverage by 2019, when the law's effect is fully realized, the researchers said.
The report, which uses a sophisticated computer simulation model to project the ACA's impact on insurance coverage, ...
PHILADELPHIA—It has long been known that cancer is a disease of aging, but a molecular link between the two has remained elusive.
Now, researchers at the Kimmel Cancer Center at Jefferson (KCC) have shown that senescence (aging cells which lose their ability to divide) and autophagy (self-eating or self-cannibalism) in the surrounding normal cells of a tumor are essentially two sides of the same coin, acting as "food" to fuel cancer cell growth and metastasis.
Michael P. Lisanti, M.D., Ph.D., Professor and Chair of Stem Cell Biology and Regenerative Medicine at Jefferson ...
Ottawa, Ontario (June 14, 2012) – Most children and youth who consume soft drinks and other sweetened beverages, such as fruit punch and lemonade, are not at any higher risk for obesity than their peers who drink healthy beverages, says a new study published in the October issue of Applied Physiology, Nutrition, and Metabolism. The study examined the relationship between beverage intake patterns of Canadian children and their risk for obesity and found sweetened beverage intake to be a risk factor only in boys aged 6-11.
"We found sweetened drinks to be dominant beverages ...
A grasshopper's change in diet to high-energy carbohydrates while being hunted by spiders may affect the way soil releases carbon dioxide into the atmosphere, according to Yale and Hebrew University researchers in Science.
Grasshoppers like to munch on nitrogen-rich grass because it stimulates their growth and reproduction. But when spiders enter the picture, grasshoppers cope with the stress from fear of predation by shifting to carbohydrate-rich plants, setting in motion dynamic changes to the ecosystem they inhabit.
"Under stressful conditions they go to different ...
Jerusalem, June 14, 2012 – How do grasshoppers who are being frightened by spiders affect our ecosystem? In no small measure, say researchers at the Hebrew University of Jerusalem and at Yale University in the US.
A grasshopper who is in fear of an attacker, such as a spider, will enter a situation of stress and will consume a greater quantity of carbohydrate-rich plants – similar to humans under stress who might eat more sweets.
This type of reaction will, in turn, cause chemical changes in the grasshopper and in its excretions, affecting the ecosystem it inhabits. ...
Computed tomographic colonography (CTC), also known as virtual colonoscopy, administered without laxatives is as accurate as conventional colonoscopy in detecting clinically significant, potentially cancerous polyps, according to a study performed jointly at the San Francisco VA Medical Center, the University of California, San Francisco and Massachusetts General Hospital.
"I think we have demonstrated that laxative-free CTC is a valid tool for detecting polyps that are clinically significant," said co-author and site principal investigator Judy Yee, MD, chief of radiology ...
Drawn together by the force of nature, but pulled apart by the force of man – it sounds like the setting for a love story, but it is also a basic description of how scientists have begun to make more efficient organic solar cells.
At the atomic level, organic solar cells function like the feuding families in Romeo and Juliet. There's a strong natural attraction between the positive and negative charges that a photon generates after it strikes the cell, but in order to capture the energy, these charges need to be kept separate.
When these charges are still bound together, ...
NEW YORK (June 14, 2012) — A novel form of vitamin B3 found in milk in small quantities produces remarkable health benefits in mice when high doses are administered, according to a new study conducted by researchers at Weill Cornell Medical College and the Polytechnic School in Lausanne, Switzerland.
The findings, recently reported in the June 2012 issue of the journal, Cell Metabolism, reveal that high doses of the vitamin precursor, nicotinamide riboside (NR) — a cousin of niacin — prevent obesity in mice that are fed a fatty diet, and also increase muscle performance, ...
