Martin Richard M, Holly Jeff M P, Gunnell David
Department of Social Medicine, University of Bristol, Bristol, UK.
Nestle Nutr Workshop Ser Pediatr Program. 2011;67:79-97. doi: 10.1159/000325577. Epub 2011 Feb 16.
There is increasing awareness that childhood circumstances influence disease risk in adulthood. As well as being strongly influenced by genes/genetic factors, stature acts as a marker for early-life exposures, such as diet, and is associated with risk of several chronic diseases in adulthood. Stature is also a marker for levels of insulin-like growth factor (IGF)-I in childhood. Levels of IGF-I are nutritionally regulated and are therefore modifiable. Milk intake in childhood and in adulthood is positively associated with higher levels of circulating IGF-I and, in children, higher circulating IGF-I promotes linear growth. Studies conducted by our team and others, however, indicate that the effect of milk is complicated because consumption in childhood appears to have long-term, programming effects which are opposite to the immediate effects of consuming milk. Specifically, studies suggest that the long-term effect of higher levels of milk intake in early childhood is opposite to the expected short-term effect, because milk intake in early-life is inversely associated with IGF-I levels throughout adult life. We hypothesize that this long-term programming effect is via a resetting of pituitary control in response to raised levels of IGF-I in childhood. Such a programming effect of milk intake in early life could potentially have implications for cancer and ischemic heart disease risk many years later.
人们越来越意识到童年时期的环境会影响成年后的疾病风险。身高不仅受到基因/遗传因素的强烈影响，还可作为早期生活暴露因素（如饮食）的一个指标，并且与成年后多种慢性疾病的风险相关。身高也是儿童期胰岛素样生长因子（IGF）-I水平的一个指标。IGF-I的水平受营养调节，因此是可以改变的。儿童期和成年期摄入牛奶均与循环中较高水平的IGF-I呈正相关，而在儿童中，较高的循环IGF-I水平可促进线性生长。然而，我们团队及其他团队进行的研究表明，牛奶的影响很复杂，因为儿童期饮用牛奶似乎具有长期的编程效应，这与饮用牛奶的即时效应相反。具体而言，研究表明，儿童期较高牛奶摄入量的长期效应与预期的短期效应相反，因为生命早期摄入牛奶与成年后一生的IGF-I水平呈负相关。我们推测，这种长期编程效应是由于儿童期IGF-I水平升高导致垂体控制重置所致。生命早期牛奶摄入量的这种编程效应可能会对多年后的癌症和缺血性心脏病风险产生潜在影响。
