We need information on the diet on which our genes evolved. We studied the milk fatty acid [FA] composition of mothers living in the island of Chole [Tanzania, Indian Ocean]. These mothers have high intakes of boiled marine fish and coconut, and consume plenty amount of fruits and vegetables. The outcome was compared with three fish-eating tribes living along Tanzanian freshwater lakes [Kerewe, Nyakius, Nyiramba], four tribes living in the Tanzanian inland [Hadzabe, Maasai, Sonjo, Iraqw] and our milk FA database. Milk from Chole contained high levels of 12:0 [20.17 g%], 14:0 [21.19], 12:0/14:0 ratio [0.92 g/g], arachidonic acid [AA, 0.50 g%] and docosahexaenoic acid [DHA, 0.73], but low levels of linoleic acid [LA, 4.23]. The combination of a high medium chain fatty acid [MCFA;