A study involving 14 years of health records from more than 274,000 Northern Californians has assessed the relative dementia risk of six different ethnicities.
The average annual rate of dementia was:
- 26.6 cases per 1,000 for blacks
- 22.2 cases per 1,000 for American Indians/Alaskan Natives
- 19.6 cases per 1,000 for Latinos and Pacific Islanders
- 19.3 cases per 1,000 for whites
- 15.2 cases per 1,000 for Asian Americans.
But this is an annual rate, not particularly useful at a practical level. How do these numbers convert to lifetime risk? Statistical calculations estimate that among those who reach age 65 dementia-free, the following percentages of each ethnicity will develop dementia in the next 25 years:
- 38% of blacks
- 35% of American Indians/Alaskan Natives
- 32% of Latinos
- 30% of whites
- 28% of Asian Americans
- 25% of Pacific Islanders (this is probably the least reliable number, given the small number of Pacific Islanders in the sample).
The study population included 18,778 African-Americans, 4543 American Indians/Alaskan Natives, 21,000 Latinos, 206,490 white Americans, 23,032 Asian-Americans, and 440 Pacific Islanders.