Obesity may increase risk of dementia and Alzheimer's
21 May 2008
Obesity in adults may increase risk of having dementia, according to
a study by the Johns Hopkins Bloomberg School of Public Health. The
researchers analysed published obesity and dementia prospective
follow-up studies over the past two decades and found a consistent
relationship between the two diseases. The results are published in the
May, 2008 issue of Obesity Reviews [1].
“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% in the United
States.”
Lead researcher May Beydoun, along with Wang and HA 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 seven of the
studies, baseline obesity compared to normal weight increased the risk
of Alzheimer’s disease by 80% 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
behavioural, 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.
Reference
1. Beydoun MA, Beydoun HA and Wang Y. Obesity and central obesity as
risk factors for incident dementia and its subtypes: a systematic review
and meta-analysis. Obesity Reviews, May 2008.