Obesity Clearly Linked to Dementia But Risk Also
Found to Increase if Underweight
Obesity increases the risk of Alzheimer’s disease by
80 percent
May 7, 2008 - Obesity may increase adults’ risk for
having dementia, according to researchers at the Johns Hopkins Bloomberg
School of Public Health. Their analysis of published obesity and
dementia prospective follow-up studies over the past two decades shows a
consistent relationship between the two diseases.
The results are published by
The International Association for the Study of Obesity in the May,
2008 issue of Obesity Reviews.
“Our analysis of the data shows a clear association
between obesity and an increased risk for dementia and several clinical
subtypes of the disease,” said Youfa Wang, MD, PhD, senior author of the
study and associate professor with the Bloomberg School’s Center for
Human Nutrition.
“Subjects with a healthy body mass index (BMI) and
waist circumference saw a decreased risk for dementia than their
counterparts with an elevated BMI or waist circumference.”
Wang adds, “Preventing or treating obesity at a
younger age could play a major role in reducing the number of dementia
patients and those with other commonly associated illnesses such as
Alzheimer’s disease by up to 20 percent in the United States.”
Lead researcher May A. Beydoun, along with Wang and
H.A. Beydoun attribute these findings to a systematic review of 10
previously published studies that examined the relationships between
dementia or its subtypes and various measures of body fat.
Based on a pooled analysis of their findings from 7
of the studies, baseline obesity compared to normal weight increased the
risk of Alzheimer’s disease by 80 percent on average.
The team further concluded that being underweight
also increases the risk of dementia and its subtypes.
The studies cited in the meta-analysis were
conducted in a number of countries, including the United States,
Finland, Sweden and France, and contained middle-aged and older adults.
Previously published research defines dementia as
not a single disorder, but a number of syndromes characterized by
diverse behavioral, cognitive, and emotional impairments. The most
common form is Alzheimer’s disease, with an estimated 5 million adults
living with the disease in the United States alone.
“Currently, Alzheimer’s disease is the eighth
leading cause of death among the elderly population in the United
States. While more studies are needed to determine optimal weight and
biological mechanisms associated with obesity and dementia, these
findings could potentially decrease the number of people diagnosed with
dementia and lead to an overall better quality of life,” said May A.
Beydoun, a former postdoctoral research fellow at the Johns Hopkins
Bloomberg School of Public Health.
"Obesity and central obesity as risk factors for
incident dementia and its subtypes: a systematic review and
meta-analysis" was written by M. A. Beydoun, H. A. Beydoun and Y. Wang.
The research was funded by the Johns Hopkins
Bloomberg School of Public Health.
