The first study, by researchers at William Beaumont Hospital, in Royal Oak, Mich., followed more than 37,000 people (averaging about 53 years of age) for almost 48 months.

• 第一个研究是密西西比州皇家橡树威廉博蒙特医院做的，纳入了超过37000的观察对象(平均约53岁），随访差不多48个月。