May 2, 2000 (San Diego) -- Before you grab that double cheeseburger, consider this: If you're middle-aged with two or more risk factors for heart disease, such as obesity and high cholesterol, your risk for dementia by your late 70s is greatly increased. Research detailing the connection between the head and the heart was presented here at the 52nd annual meeting of the American Academy of Neurology.
Dementia is a gradual breakdown in mental function characterized by memory loss, disorientation, and decline in judgment and intellect, lead researcher Sandra Kalmijn, MD, PhD, tells WebMD. Most people think of it in conjunction with Alzheimer's disease, but it has been linked to other conditions as well, such as strokes or mini-strokes.
The findings of this study reflect the long-term, negative effects of what the authors call "syndrome X," a clustering of heart-disease risk factors in one individual. Dementia risk was found to be low among men with no risk factors or only one. Obesity and a high level of certain fats in the blood were the factors most strongly associated with an increased risk of dementia. There was no association between these risk factors and the risk of developing Alzheimer's disease, says Kalmijn, an investigator at the National Institute on Aging (NIA) in Bethesda, Md.
"The point is that these risk factors seem to cluster in certain people," senior researcher Lenore J. Launer, PhD, tells WebMD. People with syndrome X have a higher risk of both heart disease and dementia, she says. Launer is chief of neuroepidemiology at the NIA.
To conduct their research, Launer and her colleagues studied participants in the Honolulu Heart Program. Between 1965 and 1968, this program enrolled all men of Japanese descent living in Honolulu, with the purpose of tracking the effects of various risk factors on heart and blood vessel disease. More than 3,500 men took part, and their average age was 53. In follow-up examinations conducted between 1991 and 1993, 215 of the then elderly men were found to be demented.
"These findings suggest that risk factors in middle age influence the risk of dementia later on," Kalmijn tells WebMD. To her, one of the most interesting findings was the association between obesity and dementia. "If one risk factor is elevated, there's a chance that the others are elevated, too," Kalmijn says. "By losing weight, exercising, stopping smoking, and eating more fruits and vegetables, you can lower most of those risk factors."
"This is an interesting study on a huge number of patients. I think the findings are [relevant]," says Thomas Arnold, MD, a neurologist at the University of Tennessee in Memphis who was not involved in study. "It is not a huge surprise that obesity is a risk factor [for dementia]," Arnold tells WebMD in an interview asking for an expert opinion of the work. "It's best to exercise, not be overweight, and not eat too much fat -- but most patients already know that."