90% of Asian Americans Cornell study National Digestive Diseases Information Clearinghouse 75 percent of African-Americans study at Cornell University found National Digestive Diseases Information Clearinghouse high lactose-intolerance levels among Africans cifras muestran 75% of black people are lactose intolerant are lactose intolerant to some degree or another cifras muestran Cornell University 50 million Americans are lactose intolerant high lactose-intolerance levels among Africans 30 million to 50 million Their survey makes sense in Asian populations