Siervo M, Wells J C K, Cizza G
Addenbrooke's Hospital, Cambridge, UK.
Horm Metab Res. 2009 Apr;41(4):261-70. doi: 10.1055/s-0028-1119377. Epub 2009 Jan 20.
The Thrifty Gene hypothesis theorizes that during evolution a set of genes has been selected to ensure survival in environments with limited food supply and marked seasonality. Contemporary environments have predictable and unlimited food availability, an attenuated seasonality due to artificial lighting, indoor heating during the winter and air conditioning during the summer, and promote sedentariness and overeating. In this setting the thrifty genes are constantly activated to enhance energy storage. Psychosocial stress and sleep deprivation are other features of modern societies. Stress-induced hypercortisolemia in the setting of unlimited food supply promotes adiposity. Modern man is becoming obese because these ancient mechanisms are efficiently promoting a positive energy balance. We propose that in today's plentifully provisioned societies, where sedentariness and mental stress have become typical traits, chronic activation of the neuroendocrine systems may contribute to the increased prevalence of obesity. We suggest that some of the yet unidentified thrifty genes may be linked to highly conserved energy sensing mechanisms (AMP kinase, mTOR kinase). These hypotheses are testable. Rural societies that are becoming rapidly industrialized and are witnessing a dramatic increase in obesity may provide a historical opportunity to conduct epidemiological studies of the thrifty genotype. In experimental settings, the effects of various forms of psychosocial stress in increasing metabolic efficiency and gene expression can be further tested.
节俭基因假说认为，在进化过程中，一组基因被选择出来，以确保在食物供应有限且季节性明显的环境中生存。当代环境中食物供应可预测且无限制，由于人工照明、冬季室内供暖和夏季空调，季节性减弱，且促进久坐不动和暴饮暴食。在这种环境下，节俭基因不断被激活以增强能量储存。心理社会压力和睡眠剥夺是现代社会的其他特征。在食物供应无限制的情况下，压力诱导的高皮质醇血症会促进肥胖。现代人正变得肥胖，因为这些古老机制有效地促进了正能量平衡。我们提出，在当今食物供应充足的社会中，久坐不动和精神压力已成为典型特征，神经内分泌系统的慢性激活可能导致肥胖患病率增加。我们认为，一些尚未确定的节俭基因可能与高度保守的能量传感机制（AMP激酶、mTOR激酶）有关。这些假说可以进行检验。正在迅速工业化且肥胖率急剧上升的农村社会可能提供一个对节俭基因型进行流行病学研究的历史机会。在实验环境中，可以进一步测试各种形式的心理社会压力对提高代谢效率和基因表达的影响。
