Does Thinness Raise Alzheimer's Risk?
Nov. 23, 2011 - In the search for early markers of Alzheimer's disease - in hopes of eventually preventing it - researchers have found that low body weight may somehow play a role.
In a study published this week in the journal Neurology, people with early signs of Alzheimer's disease were more likely to be underweight or have a low body mass index (BMI).
Earlier studies found that people who are overweight in middle age or earlier are at higher risk for Alzheimer's later in life. Other studies have shown that being overweight later in life seems to protect against the disease.
What the latest study findings mean for diagnosing or preventing Alzheimer's disease is unclear.
"A long history of declining weight or BMI could aid the diagnostic process," says study author Eric Vidoni, Ph.D., at the University of Kansas. But, he adds, it's too early "to make body composition part of the diagnostic toolbox."
Dr. Vidoni and colleagues studied brain imaging and analyzed cerebrospinal fluid in 506 people. Study participants ranged from those with no memory problems to others with Alzheimer's.
People who had evidence of Alzheimer's - either in brain scans or protein levels in the cerebrospinal fluid - were more likely to have a lower BMI than those who did not show early evidence of the disease.
The researchers aren't sure why body weight might have a bearing on Alzheimer's risk. They speculate that the disease may affect the hippocampus, the area of the brain that controls metabolism and appetite. Or, they say, perhaps inflammation is driving both the drop in BMI and the cognitive changes that are the hallmark of Alzheimer's.
Although you can't control certain risk factors for Alzheimer's disease like advancing age, you can reduce your odds of developing the condition. The latest findings show you can reduce risk by:
- Not smoking. People who light up in midlife have more than double the chances of developing dementia, including Alzheimer's disease, later in life.
- Controlling your cholesterol. High levels of LDL ("bad") cholesterol may harm your brain, as well as your heart. And an HDL ("good") cholesterol of 55 mg/dL or higher might protect you from Alzheimer's disease. Other conditions that damage the heart and blood vessels-such as diabetes and high blood pressure-may also contribute to the risk for Alzheimer's disease.
- Drinking in moderation. About 10 percent of all cases of dementia are alcohol-related. In contrast to heavy drinking, which damages the brain, moderate sipping might have brain benefits.
Always talk with your health care provider to find out more information.