NEWS--Obesity Raises Risk Of Alzheimer's Disease

[Guest guest]

Obesity Raises Risk Of Alzheimer's Disease

30 Dec 2005

If heart disease and diabetes aren't bad enough, now comes another

reason to watch your weight. According to a study just released,

packing on too many pounds can increase the risk of developing

Alzheimer's disease.

A team led by researchers at the Farber Institute for Neurosciences

at Jefferson University in Philadelphia and Edith Cowan

University in Joondalup, Western Australia has shown that being

extremely overweight or obese increases the likelihood of developing

Alzheimer's. They found a strong correlation between body mass index

and high levels of beta-amyloid, the sticky protein substance that

builds up in the Alzheimer's brain and is thought to play a major

role in destroying nerve cells and in cognitive and behavioral

problems associated with the disease.

" We looked at the levels of beta-amyloid and found a relationship

between obesity and circulating amyloid, " says Sam E. Gandy, M.D.,

Ph.D., director of the Farber Institute for Neurosciences. " That's

almost certainly why the risk for Alzheimer's is increased, " says

Dr. Gandy, who is also professor of neurology, and biochemistry and

molecular biology at Jefferson Medical College of Jefferson

University. " Heightened levels of amyloid in the blood vessels and

the brain indicate the start of the Alzheimer's process. " The

scientists reported their findings this month in the Journal of

Alzheimer's Disease.

According to, Dr. Gandy, evidence has emerged over the last five

years that many of the conditions that raise the risk for heart

disease such as obesity, uncontrolled diabetes, hypertension and

hypercholesterolemia also increase the risk for Alzheimer's. Yet

exactly how such factors made an individual more likely to develop

Alzheimer's remained a mystery.

Dr. Gandy, Ralph s, Ph.D., of Edith Cowan University and their

colleagues measured body mass index and beta-amyloid levels in the

blood. They also looked at several other factors associated with

heart disease and diabetes, such as the inflammatory marker C-

reactive protein, insulin, and high density lipoprotein in 18

healthy adults who were either extremely overweight or obese. They

found a " statistically significant correlation " between body mass

index and beta-amyloid.

" Ours is one of the first attempts to try to find out on both the

pathological and the molecular levels how obesity was increasing the

risk of Alzheimer's, " says Dr. Gandy, who serves as chairman of the

Alzheimer's Association's Medical and Scientific Advisory Council.

One implication of these findings could be that by losing excess

weight and maintaining normal body weight, an individual might

reduce the risk of developing Alzheimer's. However, this has not

been proven, notes Dr. Gandy.

" What's especially interesting about this is that several studies

are showing that even medical conditions in midlife may predispose

to Alzheimer's later on, " he says. " The baby boomers today should

pay attention to this. Their medical risk factors today will play a

role 30 years later. Think about weight, cholesterol, blood

pressure, which could affect you long-term. In terms of Alzheimer's,

another risk factor is maintaining an active mental lifestyle. "

The next step is to follow such patients over the long term to see

how many do indeed develop Alzheimer's. " We need to first develop a

medicine that is effective in humans in lowering amyloid

accumulation or generation, " says Dr. Gandy. " We have those now in

mice and we are testing them in humans. If we can develop such a

medicine, then the question will be, if we can lower amyloid, will

that in fact prevent Alzheimer's? "

Steve Benowitz

steven.benowitz@...

Jefferson University

www.jeffersonhospital.org