Navigation Links
Born to Be Obese?
Date:2/5/2008

New research suggests brains of heavy individuals may be wired differently

TUESDAY, Feb. 5 (HealthDay News) -- The brain circuitry that controls appetite might be wired differently in some people, and that could predispose them to obesity, California researchers suggest.

The study was conducted in rats, not humans, and yet it could ultimately lead to novel obesity treatments, said Philip Smith, director of the Office of Obesity Research at the National Institute of Diabetes and Digestive and Kidney Diseases.

"It is not just about drugs that modify short-term appetite," he said, "there may be drugs that stimulate development of the appropriate neural pathways. So, it is an exciting, but very early, time in this field."

The study was published in the February issue of Cell Metabolism.

Sebastien Bouret, an assistant professor of neuroscience at the University of Southern California, and his colleagues examined neural circuits emanating from the appetite, hunger and body-weight control center of the brain -- the so-called arcuate nucleus of the hypothalamus (ARH) -- in a series of rats bred to be either prone to, or resistant to, obesity.

The team found fewer neural connections projecting from the ARH in obesity-prone animals than in their leaner counterparts. Surprisingly, Bouret said, this deficiency developed very early in life, before the animals became obese, and appeared to extend into adulthood.

"Somehow, these animals are programmed to become obese," Bouret said. "The obesity is hard-wired into the brain."

When the researchers then looked at why the brains of obese rats differed from their normal-weight counterparts, they found that the neurons from obesity-prone animals were less responsive to leptin, a hormone that controls the development of these circuits, and which also signals the body's energy status and controls metabolic rate.

"This paper presumes to say, these animals must be leptin-resistant, and that is why the pathways are not developing," said Smith.

But that doesn't mean they are doomed to a life of severe obesity, said Dr. Barbara Kahn, chief of the Division of Endocrinology, Diabetes and Metabolism at Beth Israel Deaconess Medical Center, in Boston. How they live their lives also matters.

"It is important not to 'blame' the obese person or imply that he/she is responsible for being obese," Kahn noted. "Having said that, reasonable, healthy caloric restriction and a safe and sustainable program of physical activity can help limit weight gain and often bring about some degree of weight loss. In addition, healthy eating and regular exercise can reduce the complications of obesity such as type 2 diabetes and cardiovascular disease."

At the same time, she added, not everyone can wear a size 4.

"There is a certain aspect of genetics that sets somebody in a certain range of possible body weights, and then how that person lives his or her life will determine whether they are at the bottom or top of the range," she explained.

Human obesity has both genetic and environmental roots. The rats used in this study, like most humans, developed obesity when fed a high-energy diet. On a normal diet, they were heavier than normal rats, but not yet obese.

"This is quite an exciting paper," said Smith, "because it links more closely to human behavior than most rodent models we have seen."

The findings also suggest a possible therapeutic approach to combating human obesity. If drugs could be designed to influence the formation of neural circuits during development and targeted to at-risk pregnancies, Smith said, "there is a good likelihood we could have successful interventions that improve the health of the mother, and which have a major impact on disease risk for the infant, during pregnancy."

A related study from Boston University researchers in the same journal found that bulking up muscle mass can lead to a general metabolic improvement in obese individuals. "Interventions designed to increase skeletal muscle mass in at-risk human populations may prove to be critical weapons in the fight against obesity and obesity-related comorbidities, including diabetes, heart disease, stroke, hypertension and cancer," an accompanying editorial stated.

More information

For more on obesity, visit the National Institute of Diabetes and Digestive and Kidney Diseases.



SOURCES: Sebastien G. Bouret, Ph.D., assistant professor, neuroscience, University of Southern California, Los Angeles; Philip Smith, Ph.D., co-director, Office of Obesity Research, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Md.; Barbara Kahn, M.D., chief, Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, and George R. Minot Professor of Medicine, Harvard Medical School, both in Boston; February 2008, Cell Metabolism


'/>"/>
Copyright©2008 ScoutNews,LLC.
All rights reserved  

Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Born to Be Obese?
(Date:5/1/2016)... ... , ... ProBrand Reveal Volume 2 is a set of versatile and smooth logo reveals built ... users can easily create a unique logo reveal in just a matter of minutes. Custom ... these title presets to add a uniquely animated logo to any photos or videos. , ...
(Date:4/30/2016)... ... May 01, 2016 , ... Serenity Recovery, a substance abuse ... produced a new video that focuses on one of the more popular of their ... clips from interviews with a participating patients and the Yoga class instructor, this video ...
(Date:4/30/2016)... , ... April 30, 2016 , ... ... announced RANKED Health , a program to critically evaluate and rank health-focused ... of the program is to provide independent, unbiased and accurate information to help ...
(Date:4/30/2016)... ... April 30, 2016 , ... ... 4th, 2016 questioned the use of the HyProCure sinus tarsi implant. ( ... procedure.” EOTTS-HyProCure is a minimally invasive procedure performed, when indicated, to correct ...
(Date:4/29/2016)... ... 30, 2016 , ... World Patent Marketing , a ... an automotive invention that improves the storage features of a pick up truck. ... Scott Cooper, CEO and Creative Director of World Patent Marketing. "Over the next ...
Breaking Medicine News(10 mins):
(Date:4/29/2016)... ISELIN, New Jersey , April 29, 2016 ... Omnichannel Software Suite for Life Sciences, Product Development ... and Global Life Science Customer Base . ... healthcare solutions provider, today announced the acquisition of ... is a global leader in adaptive sales enablement ...
(Date:4/29/2016)... April 29, 2016 Glycotope GmbH, ... today announces the appointment of Dr. Alfredo Zurlo ... is an oncologist with many years clinical experience and ... industries. His last role was at Mologen AG where ... Executive Board. Previously Dr. Zurlo held various positions at ...
(Date:4/28/2016)... April 28, 2016   Click here for ... Inc. (NYSE: DPLO), the nation,s largest independent specialty ... definitive agreement to acquire Valley Campus Pharmacy, Inc., ... a leading specialty pharmacy that provides individualized patient ... . In 2015, TNH generated approximately $400 ...
Breaking Medicine Technology: