Seeds of Dementia Sown in Midlife

Identifying, treating cardiovascular risk factors early might make difference, study says

MONDAY, Jan. 24, 2005 (HealthDayNews) -- If you are middle-aged and have high cholesterol or high blood pressure, or are a diabetic or smoker, you face a significantly higher risk of developing dementia in your later years, a new study suggests.

Each of these cardiovascular risk factors was associated with a 20 percent to 40 percent increased risk, claims the report in the Jan. 25 issue of Neurology.

This is the first time such a risk profile has been seen in middle age, said study author Rachel Whitmer, from the Kaiser Permanente Division of Research. "There have been other studies that show that cardiovascular risk factors increase the risk of dementia in late life," she added.

There is good news and bad news, Whitmer said. "The bad news is that these risk factors, which we know are associated with risk of cardiovascular disease, also increase one's risk of dementia. The good news is that if these risk factors are identified in middle age, it leaves some hope that earlier identification and earlier treatment might reduce or possibly prevent dementia."

In their study, Whitmer and her colleagues collected data on 8,845 men and women aged 40 to 44, from 1964 to 1973. By looking at medical records, the research team was able to determine cardiovascular risk factors. And when the team looked at the same medical records from January 1994 to April 2003, they found that 721 patients had been diagnosed with dementia.

The researchers found that each of the cardiovascular risk factors was predictive, according to Whitmer. Those with diabetes were 46 percent more likely to develop dementia; those with high cholesterol were 42 percent more likely; people who smoked were 26 percent more likely, and those who had hypertension were 24 percent more likely.

And when they looked at a combination of the risk factors, they found the risk for dementia increased from 27 percent for one risk factor to 237 percent for having all four risk factors, compared with having no risk factors, Whitmer said.

People shouldn't wait until they are in their 50s to get their cholesterol or their blood pressure checked, and to quit smoking, Whitmer said. "It is important to know your risk factors much earlier," she added.

"Earlier identification and treatment is really important," Whitmer added. "Dementia is also another bad outcome of some of these common diseases."

According to Whitmer, some studies have shown that treating cardiovascular risk factors such as high cholesterol lowers the risk of cognitive decline. But more research is needed to see if reducing cardiovascular risk factors reduces the risk of dementia, she said.

"This study agrees with data coming from various studies," said Dr. Samuel Gandy, vice chairman of the National Medical and Scientific Advisory Council of the Alzheimer's Association.

Gandy noted that other studies have shown that even if some of these risk factors are identified and treated in midlife, it may not be possible to prevent dementia from developing.

"We know that Alzheimer's begins at least 10 or more years before the first clinical signs are evident," Gandy said. "It is possible that setting that cascade in motion in midlife may be like a runaway train. It may be difficult to get it back on the track."

To have the best chance of reducing your risk of dementia, you need to get control of these risk factors as soon as possible, Gandy stressed: "You can't sort of wait and try to get all these things under control when you're 50 or 55."

In a statement released in response to Whitmer's study, the Alzheimer's Association made these recommendations to keep dementia at bay:

  • Stay mentally active: read, take a class, work crossword puzzles, play games.
  • Stay physically active: walk, bike, jog, garden, practice tai chi or yoga.
  • Remain socially involved: volunteer, take a dance class, travel.
  • Adopt a brain healthy diet: eat dark-skinned fruits and vegetables, fish and nuts.

More information

The Alzheimer's Association can tell you more about Alzheimer's disease.

SOURCES: Rachel Whitmer, Ph.D., Kaiser Permanente Division of Research, Oakland, Calif.; Samuel Gandy, M.D., Ph.D., professor, neurology, director, Farber Institute, Thomas Jefferson University, Philadelphia, and vice chairman, National Medical and Scientific Advisory Council, Alzheimer's Association, Chicago; Jan. 25, 2005, Neurology
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