The rate of dementia among Māori is unusually low compared with other indigenous peoples—possibly due to the beneficial effects of song, dance and speaking more than one language.
A University of Auckland study followed about 400 Māori and 500 non-Māori in their 80s for five years, and found the rate of dementia in both groups was 26 per cent.
Ngaire Kerse, one of the study’s authors, said she expected the Māori participants to have a higher prevalence of dementia than non-Māori, because they had a higher prevalence of dementia risk factors. (These include diabetes, heart disease, obesity, smoking and lack of education.)
Indigenous populations usually suffer from dementia at higher rates than the general population. Previous research has shown indigenous Australians have at least three times the rate of dementia of non-indigenous Australians, while a systematic review in 2015 found the prevalence of dementia was also higher in the indigenous peoples of Canada, the United States, Guam and Brazil.
The unexpected results may be due to “the bilingual nature of the participants’ lives”, says Kerse. At least half the Māori participants were fluent in te reo, and the others used the language most days. It is generally thought lifelong bilinguals have stronger brain connections, which help to cope with age-related damage. Kerse also pointed to kapa haka as a mitigating factor, likening it to a study conducted in New York in 2003, where the only physical activity to reduce the likelihood of contracting Alzheimer’s was ballroom dancing.