[ti:Obesity and Brain Development: Is There a Link?][by:shang05.com][00:00.00]更多听力请访问shang05.com[00:01.08]In the United States, about 25 million children are either overweight or obese.[00:09.56]A new study explored how being overweight or obese might affect brain development in children.[00:19.04]A report on the study appeared this month in JAMA Pediatrics,[00:24.56]a publication of the American Medical Association.[00:29.80]The writers suggested a link between body mass index, brain development[00:36.44]and "executive functions, such as working memory."[00:41.56]An editorial published with the report called the study an important addition[00:48.12]to growing evidence of a link between weight, brain structure and mental function.[00:56.32]It also warned against misinterpreting the findings.[01:01.96]The study involved 3,190 U.S. boys and girls, aged 9 and 10.[01:11.84]Researchers had height and weight measurements and MRI scans of their brains.[01:19.28]MRI is short for magnetic resonance imaging,[01:24.48]a method used to take pictures of organs and tissues within the body.[01:31.44]The children took computer-based tests of mental function,[01:36.48]including memory, language, reasoning and impulse control.[01:43.32]Nearly 1,000 of the kids — almost 1 in 3 — were overweight or obese, similar to levels nationwide.[01:54.52]Researchers found differences in the brain scan images of the heaviest children.[02:02.32]They observed slightly less volume -- the amount of space -- in the brain behind the forehead.[02:09.64]This area controls what are known as "executive function" tasks.[02:15.68]Such tasks include things like planning, controlling impulses[02:21.32]and dealing with two or more activities at the same time.[02:27.00]Compared with normal-weight children, the differences were small,[02:32.44]noted Scott Mackey, a neuroscientist at the University of Vermont.[02:39.04]The heaviest children also had slightly worse results on the computer-based tests of executive function.[02:49.16]But it is unknown whether any of the differences[02:53.20]had much of an effect on children's behavior or performance in school.[02:59.28]Those are the opinions of Mackey and Jennifer Laurent, a University of Vermont researcher.[03:06.76]Laurent was the lead author of the report on the study.[03:12.04]It is also unclear how the differences relate to weight.[03:17.60]Mackey said other factors not measured in the study,[03:22.08]including physical activity and good nutrition, are likely important.[03:29.08]Research in adults has linked obesity with low-level inflammation throughout the body.[03:37.36]The condition can damage blood vessels and may increase risks for heart disease and loss of mental ability.[03:46.60]Some studies have also found less brain volume in obese adults.[03:52.88]Researchers suspect that the decreased brain volume could be from inflammation.[04:00.92]The new study raises the possibility that inflammatory changes affecting weight,[04:07.48]brain structure and brain function might begin in childhood.[04:14.20]Eliana Perrin is a doctor and specialist of children's health at Duke University in North Carolina.[04:23.32]She co-wrote the editorial published in JAMA Pediatrics.[04:28.40]She says that people should be careful about how they interpret the study.[04:34.56]"We don't know which direction these relationships go nor do they suggest[04:40.92]that people with obesity are not as smart as people at a healthy weight," she said.[04:47.96]The latest research confirms results of earlier studies in children and adults,[04:54.80]but it leaves many questions unanswered, said Marci Gluck.[05:00.64]Gluck is with the U.S. National Institute of Diabetes and Digestive and Kidney Diseases.[05:08.12]She was not part of the research, and warned people against making a link[05:13.92]between executive function and intelligence.[05:17.72]Natasha Schvey is an obesity researcher with the Uniformed Services University of the Health Sciences.[05:27.96]She called the study impressive, but noted that many factors influence people's diets and obesity.[05:38.08]"We know from a lot of really good research that obesity is not as much[05:43.68]in an individual's control as we think it is.[05:48.04]People talk about willpower — that's a very small part of the equation," she said.[05:54.32]"There are much bigger contributors to our weight and a lot of it is genetic."[06:01.20]I'm John Russell. 更多听力请访问shang05.com