eng Science and Education Publishing Journal of Food and Nutrition Research 2333-1240 2014-10-26 2 11 806 813 10.12691/jfnr-2-11-8 JFNR20142118 article Meihong Xu 1 2 Rui Liang 2 2 Qianying Guo 2 2 Shuangjia Wang 2 2 Ming Zhao 2 2 Zhaofeng Zhang 2 2 Junbo Wang 2 2 Yong Li liyongbmu@163.com 2 2 Department of Nutrition and Food Hygiene, School of Public Health, Peking University, Beijing, PR China To assess the long-term toxicity and carcinogenicity of dietary nucleotides (NTs), Sprague-Dawley rats were administered the NTs for life-through with the dose of 0, 0.01%, 0.04%, 0.16% and 0.64%. With the exception of several groups, the results showed no significant differences in weight gain, clinical symptoms data, blood indicators, and Non-neoplastic lesions frequencies. NTs have dramatically increased the food consumption of both sexes (P<0.05). Meanwhile, NTs decreased spontaneous tumor incidence of both sexes, notably the male rats (P<0.05). The occurrence of all malignant and mammary tumors in NTs-treated females was lower than those in controls (P<0.05). In comparison with the control group, the incidence of death from malignant and systemic tumors were obviously decreased in the NTs-treated groups (P<0.01). Moreover, our results showed that a higher percentage of rats in the NTs-treated groups died of non-neoplastic lesions compared with control. In conclusion, dietary nucleotides are not toxic or carcinogenic in rats up to 0.64% for all the life, and 0.64% was an unobservable e?ect dose. http://pubs.sciepub.com/jfnr/2/11/8/jfnr-2-11-8.pdf dietary nucleotides safety lifelong Spontaneous Tumor Incidence Sprague-Dawley rat