摘要：美国研究者宣布发现烟民在戒烟后容易发胖的原因。
6月10日出版的《科学》期刊发表美国耶鲁大学科学家扬·米纳尔的一篇论文，文章借助实验鼠发现，香烟中的尼古丁可附着在大脑中控制食欲的神经元细胞上，导致这些细胞变得兴奋，过快发出“吃饱”的信号。
戒烟之后人会感觉食欲变佳
而戒烟之后，这些神经元细胞不再被尼古丁“绑架”，因此兴奋度降低，发出“吃饱”信号的时间延长。换句话说，使人感觉食欲变佳。
在美国烟民中进行的一项调查显示，烟民在戒烟后体重平均增加5公斤。
米纳尔在论文中写道，许多烟民以担心戒烟后发胖为由拒绝戒烟，这一研究有助于寻找一种治疗方法，帮助烟民在戒烟的同时，放缓“食欲变佳”的速度。
米纳尔说，吸烟可增加癌症、心血管系统等疾病的发病率，与这些可致命疾病相比，体重增加对健康所构成危害较小，因此，担心发胖不是拒绝戒烟的理由。但如果实在惧怕发胖，可使用尼古丁替代疗法帮助戒烟。
生物探索推荐英文原文：
Science 10 June 2011:
Vol. 332 no. 6035 pp. 1330-1332
DOI: 10.1126/science.1201889
Nicotine Decreases Food Intake Through Activation of POMC Neurons
Abstract: Smoking decreases appetite, and smokers often report that they smoke to control their weight. Understanding the neurobiological mechanisms underlying the anorexic effects of smoking would facilitate the development of novel treatments to help with smoking cessation and to prevent or treat obesity. By using a combination of pharmacological, molecular genetic, electrophysiological, and feeding studies, we found that activation of hypothalamic α3β4 nicotinic acetylcholine receptors leads to activation of pro-opiomelanocortin (POMC) neurons. POMC neurons and subsequent activation of melanocortin 4 receptors were critical for nicotinic-induced decreases in food intake in mice. This study demonstrates that nicotine decreases food intake and body weight by influencing the hypothalamic melanocortin system and identifies critical molecular and synaptic mechanisms involved in nicotine-induced decreases in appetite.
