Low BMI May Contribute to Alzheimer's

Maintaining a weight that is overly thin can contribute to health problems in much the same way that being obese can. More recently a low body mass index has also been linked to early stages of Alzheimer's disease.

In a study that examined BMI and its impact on Alzheimer's, University of Kansas researchers also found that those who are overweight in middle age may be more susceptible to developing Alzheimer's decades later as compared to individuals of a normal weight.

Maintain a healthy weight through diet and exercise.

Dr. Jeffrey M. Burns, a physician from the University of Kansas School of Medicine, said that the results suggest that brain changes that occur with Alzheimer's disease are associated with metabolic changes in the very earliest phases of the disease.

He hypothesized that this could be because of an area of the brain called the hypothalamus that plays a role in regulating energy metabolism and food intake.

Researchers examined 506 participants who were part of the Alzheimer's Disease Neuroimaging Initiative by using advanced brain imaging techniques. The study included patients with mild cognitive impairment, mild memory problems, Alzheimer's disease and those without memory problems.

They also analyzed cerebrospinal fluid to search for biomarkers for Alzheimer's disease, which can be detected before symptoms begin.

They found that in patients with no thinking problems or mild cognitive impairment , those with Alzheimer's biomarkers were more likely to have a low BMI.

Investigators found that 85 percent of patients with mild cognitive impairment with a BMI below 25 had signs of beta-amyloid plaques in the brain, a hallmark of Alzheimer's disease, as compared to 48 percent with mild cognitive impairment who were overweight. They found a similar relationship among participants with no memory problems.

The study was published in the Nov. 22 issue of Neurology, the medical journal of the American Academy of Neurology.