The higher your cholesterol in midlife, the higher your chances of getting dementia or Alzheimer's disease later in life, according to new research.

Doctors from Kaiser Permanente University of Kuopio in Finland studied nearly 10,000 people for 40 years. Those with cholesterol levels over 240 when they were in their early 40s had a 66 percent greater chance of having dementia, they said in a news release.

Even those who had levels considered only borderline-high -- in the 200-240 range -- had a 52 percent increase risk.

"Considering that nearly 100 million Americans have either high or borderline cholesterol levels, this is a disturbing finding," said Rachel Winter of Kaiser Permanente. "The good news here is that what is good for the heart is also good for the mind."

Dr. Alina Solomon, who also worked on the project, said the results show that the roots of dementia and cardiovascular disease come from several factors working together, showing that a holistic approach should be used to treat those conditions.

The study appeared in the journal Dementia & Geriatric Cognitive Disorders.