Three quarters of the adult Tutsi of Rwanda and Burundi have a high ability to digest lactose, while only 5% of the adults of the neighboring Shi people of eastern Congo can.
Tri četvrtine odraslih Tutsiji Ruande i Burundija imaju visoku sposobnost probave laktoze, dok samo 5% odraslih iz susjednog naroda Shi u istočnom Kongu to mogu.