So Pacific islanders never suffer dementia?
It seems their rates for dementia/Alzheimer’s is fairly low.
Fiji comes in third to last for their rate.
http://www.worldlifeexpectancy.com/cause-of-death/alzheimers-dementia/by-country/
I just looked up the diet of Fijians.
The basics of Fijian food consists of rice, sweet potatoes, taro, cassava, coconut and fish; and using mostly open fire or underground cooking methods, the ingredients are made into one of the following national dishes. The heavy influence of the Indo-Fijian culture also means the cuisine has elements of colorful curries and spices with it.
(Did you see that coconut is in there?)