我没有survivorship bias，1/10 of age >= 65 has AD in US;

that number is 1/20 in China. 2/3 of Americans with AD are women; that number is 7/26 in China. By all indicators, highly educated Chinese males are lucky ones. Having said that，我曾与高锟做过短期的同事，a very sharp and kind小个子，很不幸落入AD魔掌。家父，教授，从不锻炼，a chain smoker, 有糖尿病，最后很衰竭但脑子清楚，活到88。身高与AD发病率有负相关，但不知是身高本身，还是与身高成正相关的幼儿脑发育期的营养状态。老妈二战时在教会学校学的医，早过了90还喜欢与我争论。她最内疚的是我小时候托红太阳的福营养不良，至今还留有我在幼儿园的健康卡，身高体重都不达她教科书的标。