People who have high blood pressure, cholesterol, diabetes or who smoke in midlife have a much higher risk of developing Alzheimer’s disease later on, U.S. researchers reported Monday.
And the more factors a person has, the higher the risk. People with all four risk factors have more than double the risk of Alzheimer’s, the team at the Kaiser Permanente Division of Research in Oakland, Calif., found.
“The message is that the risk factors that are bad for the heart are bad for the brain,” said Dr. Marilyn Albert, chair of scientific and medical research at the nonprofit Alzheimer’s Association.
“That largely is because what happens to blood vessels in the heart is same as what happens to blood vessels in the brain,” added Albert, whose group was not involved in the study.
For the report, published in the journal Neurology, Rachel Whitmer and colleagues studied nearly 9,000 people living in northern California.
The men and women from various ethnic groups were followed for 27 years. Those with diabetes at age 40 to 45 were 46 percent more likely to develop dementia later on.
People with high cholesterol were 42 percent more likely to develop dementia while those with high blood pressure were 24 percent more likely.
Smokers were 26 percent more likely to develop dementia.
Smokers with diabetes, high blood pressure and high cholesterol were more than twice as likely to develop dementia, Whitmer and colleagues reported.
People who were treated for their conditions lowered their overall risk of Alzheimer’s, however.
“The real strength of our study is the large, multiethnic cohort of men and women, followed up for 27 years, all with equal access to medical care,” Whitmer said.
Alzheimer’s affects an estimated 4.5 million Americans but this number is expected to jump to 16 million by 2050 as the population ages.
A team at Thomas Jefferson University in Philadelphia reports in the Public Library of Science this month that taking statin drugs, which lower cholesterol, also reduces the risk of Alzheimer’s. Heart experts believe the drugs not only reduce cholesterol levels but somehow also keep the linings of blood vessels healthy.
Doctors say the prescriptions for avoiding heart disease and for lowering the risk of Alzheimer’s are similar -- eat plenty of fresh fruits and vegetables and nuts, and exercise daily.
The Alzheimer’s Association advocates mental and physical exercise to help lower the risk of the deadly and incurable brain disease.
“We can’t prevent it but we can do an awful lot in our daily life to reduce risk,” Albert said.
Physical, mental and social activity all seem to be important, she said. Studies in the December issue of Neurology showed people who exercised and who had social connections had less risk of mental decline.