PRELIMINARY REPORT ON THE RESULTS OF NUTRITION PREVENTION TRIALS OF CANCER AND OTHER COMMON DISEASES AMONG RESIDENTS IN LINXIAN, CHINA

摘要

To examine whether vitamin / mineral supplementation may lower mortality and incidence for human cancer and mortality from other diseases as well as to provide the scientific basis and feasible approach for human cancer prevention and control, from 1982 to 1991 scientists from China and USA conducted two randomized, double-blind, placebo-controlled nutrition intervention trials in Linxian, China, where the mortality rates of esophageal and gastric cardia cancer are among the highest in the world and there is suspicion that the population's chronic deficiencies of multiple nutrients are etiologically involved. In the first trial, the Dysplasia trial, 3318 individuals with a cytological diagnosis of esophageal dysplasia received daily 26 vitamin / mineral supplements or placebo for 6 years. The second trial, the General Population Trial, involved 29584 individuals and used a one—half replicate of a 2~4 fractional factorial design that randomized to 8 groups for testing the effects of daily supplementation of 4 different vitamin / mineral combinations and placebo for a period of 5.25 years. Compliance assessed by monthly pill counts and quarterly monitoring of biochemical assays indicated that the participant compliance was excellent. As endpoints of the trials, incident cancers and deaths were identified through all medical facilities in local areas, supplemented by special endoscopy and cytology examinations, and confirmed by 3—level review groups.