Barnard R James
Department of Physiological Science, University of California, Los Angeles, CA 90096-1606, USA.
Am J Clin Nutr. 2007 Sep;86(3):s889-93. doi: 10.1093/ajcn/86.3.889S.
In 1987 when Reaven introduced syndrome X (metabolic syndrome, or MS), we were studying skeletal muscle insulin resistance and found that when rodents were fed a high-fat, refined-sugar (HFS) diet, insulin resistance developed along with aspects of MS, including hyperinsulinemia, hypertension, hypertriglyceridemia, and obesity. MS was controlled in rodents by switching them to a low-fat, starch diet and was controlled in humans with a low-fat starch diet and daily exercise (Pritikin Program). Others reported inverse relations between serum insulin and sex hormone-binding globulin (SHBG). When subjects were placed on the Pritikin Program, insulin fell and SHBG rose and it was suggested that prostate cancer might also be an aspect of MS. A bioassay was developed with tumor cell lines grown in culture and stimulated with serum before and after a diet and exercise intervention. Diet and exercise altered serum factors that slowed the growth rate and induced apoptosis in androgen-dependent prostate cancer cells. Changes in serum with diet and exercise that might be important include reductions in insulin, estradiol, insulin-like growth factor-I (IGF-I), and free testosterone with increases in SHBG and IGF binding protein-1. Hyperinsulinemia stimulates liver production of IGF-I, plays a role in the promotion of prostate cancer, and thus is the cornerstone for both MS and prostate cancer. Adopting a low-fat starch diet with daily exercise controls MS and should reduce the risk of prostate cancer.
1987年，当雷文提出X综合征（代谢综合征，简称MS）时，我们正在研究骨骼肌胰岛素抵抗，发现当给啮齿动物喂食高脂、高糖（HFS）饮食时，胰岛素抵抗会伴随MS的一些症状出现，包括高胰岛素血症、高血压、高甘油三酯血症和肥胖。通过将啮齿动物改为低脂、高淀粉饮食，MS得到了控制；而在人类中，通过低脂高淀粉饮食和日常锻炼（普里蒂金计划）也能控制MS。其他人报告了血清胰岛素与性激素结合球蛋白（SHBG）之间的负相关关系。当受试者采用普里蒂金计划时，胰岛素水平下降，SHBG水平上升，有人提出前列腺癌可能也是MS的一个方面。我们开发了一种生物测定法，用培养的肿瘤细胞系，在饮食和运动干预前后用血清进行刺激。饮食和运动改变了血清因子，减缓了雄激素依赖性前列腺癌细胞的生长速度并诱导其凋亡。饮食和运动引起的血清变化可能很重要，包括胰岛素、雌二醇、胰岛素样生长因子-I（IGF-I）和游离睾酮的减少，以及SHBG和IGF结合蛋白-1的增加。高胰岛素血症刺激肝脏产生IGF-I，在前列腺癌的发展中起作用，因此是MS和前列腺癌的共同基石。采用低脂高淀粉饮食并进行日常锻炼可以控制MS，并应降低患前列腺癌的风险。
