Ross M H, Lustbader E D, Bras G
Nutr Cancer. 1982;3(3):150-67. doi: 10.1080/01635588109513717.
A complete life history was obtained of the dietary practices, growth responses, and diseases of outbred male Charles River COBS rats permitted to select their own diets. Simple correlation analyses proved inadequate for detecting an association between any single factor at any age and tumor development. A multifactorial model showed that animals that developed tumors could be distinguished from those that did not, solely on the basis of age- or weight-specific information prior to maturity. The combination of variables that maximize the probability of a neoplasm is: 1. a high absolute protein intake shortly after weaning, 2. a high degree of efficiency in converting consumed food into body mass at the time the individual enters puberty, 3. a high level of protein intake relative to body weight during the early adult period and concomitantly, 4. a high level of food intake, and 5. a rapid growth rate during early postnatal life so that comparatively less time is required to attain a specified body weight than a subsequent weight increment. The opposite set of conditions reduces the probability of neoplasm occurrence, which is even further minimized if the proportion of protein in the diet in early postweaning life and the absolute intake of protein during the early adult period are relatively high. Differences in temporal-specific dietary practices and growth responses accounted for differences in the tissue origin of the tumors.
我们获取了一组远交雄性查尔斯河COBS大鼠的完整生活史，这些大鼠可以自行选择饮食，记录了它们的饮食习惯、生长反应和疾病情况。简单的相关性分析不足以检测任何年龄的单一因素与肿瘤发生之间的关联。多因素模型表明，仅根据成熟前的年龄或体重特定信息，就可以区分出发生肿瘤的动物和未发生肿瘤的动物。使肿瘤发生概率最大化的变量组合是：1. 断奶后不久蛋白质绝对摄入量高；2. 个体进入青春期时将摄入食物转化为体重的效率高；3. 成年早期相对于体重的蛋白质摄入量高，同时；4. 食物摄入量高；5. 出生后早期生长速度快，因此达到特定体重所需的时间比随后的体重增加所需时间相对较短。相反的一组条件会降低肿瘤发生的概率，如果断奶后早期饮食中蛋白质的比例和成年早期蛋白质的绝对摄入量相对较高，肿瘤发生概率会进一步降低。特定时间的饮食习惯和生长反应的差异导致了肿瘤组织起源的差异。
