Racial, ethnic factors turn up for Alzheimer's

Scientists look for causes of the dementia.
HARTFORD COURANT
CROMWELL, Conn. -- Japanese who live in Hawaii are at greater risk of getting Alzheimer's disease than Japanese living in Japan or in mainland United States. Elderly Chinese may be more difficult to diagnose with dementia because of cultural practices and stigma attached to mental illness.
The devastation of dementia is global, but researchers are finding intriguing racial and ethnic variations to the tragedy of Alzheimer's, said Dr. Tiffany Chow, assistant professor of neurology at the University of Toronto, who was the keynote speaker Thursday at the Connecticut Alzheimer's Education Conference.
Those differences may suggest new ways to prevent or treat the disease, Chow told 550 people who attended the conference sponsored by the Connecticut chapter of the Alzheimer's Association.
Risk factor: age
There is one risk factor for Alzheimer's that is universal -- age. The risk of Alzheimer's doubles every five years after the age of 60, Chow said. But other risk factors tend to vary depending on racial background or where the person is born.
Chow said it is still a mystery why Hawaiian Japanese have higher rates of Alzheimer's than Japanese living elsewhere. An unsubstantiated report that tofu might be to blame unleashed a furor in the Islands, Chow said.
"People said, 'We can't live without our tofu,'" she said.
But it is important to investigate such differences in incidence, she said, because they may lead to clues about new risk factors or even treatments.
Studies have shown that blacks living in Indianapolis have twice the rate of Alzheimer's as Africans living in Nigeria.
Strokes, hypertension
One explanation for the difference is that black Americans are almost 10 times more likely to have strokes or hypertension than their African peers, she said. Stroke and hypertension have turned out to be risk factors for both vascular dementia and Alzheimer's, she said.
"Could diet be to blame? Sure," said Chow, who noted that Africans were more likely to be vegetarians.
Because they are more prone to strokes may be one reason black people are almost twice as likely as white people to develop Alzheimer's.
"People don't seem to be too concerned with preventing strokes, but if you tell them this is a way to prevent Alzheimer's, their reaction might be different," Chow said.
Statin drugs, which lower cholesterol and are prescribed for cardiovascular disease, also may help prevent Alzheimer's and might be particularly beneficial for blacks, she said.
Doctors also should be aware of cultural differences that may affect the diagnosis of dementia. Elderly Chinese women, for instance, tend to live with children, who seldom ask them to do much work, Chow said. Also, in the Chinese culture it is considered an insult to suggest that a family member has any type of mental disability, she said.
So, Chow said, telltale signs of Alzheimer's could be overlooked for longer periods of time in this population.