【注：在网络新闻上看到路透社的报道，下面是原文连接。为方便读者，加上一些色彩和注解。】 http://www.reuters.com/article/idUSTRE62R23O20100328 Junk food addiction may be clue to obesity (By JoAnne Allen, Washington, March 28, 2010, 7:38pm EST) (Reuters) - Bingeing on high-calorie foods may be as addictive as cocaine or nicotine, and could cause compulsive eating and obesity, according to a study published on Sunday. 【注：原始文献在本文最后有连接和摘要】 The findings in a study of animals cannot be directly applied to human obesity, but may help in understanding the condition and in developing therapies to treat it, researchers wrote in the journal Nature Neuroscience . The study, involving rats, found that overconsumption of high-calorie food can trigger addiction-like responses in the brain and that high-calorie food can turn rats into compulsive eaters in a laboratory setting, the article said. The scientists also found decreased levels of a specific dopamine receptor -- a brain chemical that allows a feeling of reward -- in overweight rats, as has been reported in humans addicted to drugs, the article said. Obesity may be a form of compulsive eating. Other treatments in development for other forms of compulsion, for example drug addiction, may be very useful for the treatment of obesity, researcher Paul Kenny of The Scripps Research Institute in Florida said in a telephone interview. Obesity-related diseases cost the United States an estimated $150 billion each year , according to U.S. federal agencies . An estimated two-thirds of American adults and one-third of children are obese or overweight. 【中国在肥胖症人口也在不断增加， http://eladies.sina.com.cn/zc/2008/0710/1356738701.shtml 上面那个网页说中国有3.25亿胖子。真的那么多吗？太可怕了！各种和肥胖有关的疾病将给社会带来无穷的负担！】 For the study, Kenny and colleagues headed to the grocery store. We basically bought all of the stuff that people really like -- Ding-Dongs, cheesecake, bacon, sausage, the stuff that you enjoy, but you really shouldn't eat too often, he said. They also bought healthy foods and devised a diet plan for three groups of rats. One group ate a balanced healthy diet. Another group received healthy food, but had access to high-calorie food for one hour a day. Rats in the third group were fed healthy meals and given unlimited access to high-calorie foods. The rats in the third group developed a preference for the high-calorie food, munched on it all day and quickly became obese , Kenny said. The rats in the experiment had also been trained to expect a minor shock when exposed to a light. But when the rats that had unlimited access to high-calorie food were shown the light, they did not respond to the potential danger, Kenny said. Instead, they continued to eat their snacks. What we're seeing in our animals is very similar to what you'd see in humans who overindulge , he said. It seemed that it was okay, from what we could tell, to enjoy snack foods, but if you repeatedly overindulge, that's where the problem comes in. 【至少人和老鼠一样服从热力学第一定律，吃的越多，吸收的能量就多，如果再不锻炼能不长肥肉吗？】 【本文相关的研究论文】 http://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.2519.html Dopamine D2 receptors in addiction-like reward dysfunction and compulsive eating in obese rats， by Paul M Johnson Paul J Kenny , Nature Neuroscience, 2010, doi:10.1038/nn.2519 Abstract We found that development of obesity was coupled with emergence of a progressively worsening deficit in neural reward responses. Similar changes in reward homeostasis induced by cocaine or heroin are considered to be crucial in triggering the transition from casual to compulsive drug-taking. Accordingly, we detected compulsive-like feeding behavior in obese but not lean rats, measured as palatable food consumption that was resistant to disruption by an aversive conditioned stimulus. Striatal dopamine D2 receptors (D2Rs) were downregulated in obese rats, as has been reported in humans addicted to drugs. Moreover, lentivirus-mediated knockdown of striatal D2Rs rapidly accelerated the development of addiction-like reward deficits and the onset of compulsive-like food seeking in rats with extended access to palatable high-fat food. These data demonstrate that overconsumption of palatable food triggers addiction-like neuroadaptive responses in brain reward circuits and drives the development of compulsive eating. Common hedonic mechanisms may therefore underlie obesity and drug addiction.
标签: 垃圾食品
