One out of every 20 individuals over the age of 65 has dementia. Living a healthy lifestyle early in life which includes watching your weight with exercise and portion control can help prevent the subsequent development of dementia. The link between obesity and the subsequent development of dementia later in life is well documented in the medical literature. A new study suggests that being just overweight instead of obese in midlife can increase the risk of subsequently developing several types of dementia. The study was published in the current issue of the journal Neurology. Researchers from Sweden looked at about 8,500 twins in the Swedish Twin Registry and evaluated the correlation between their body mass index in midlife and the eventual development of dementia. Several types of cognitive deficits disorders were evaluated and included dementia, Alzheimer’s disease, and vascular dementia. Being overweight was defined as a BMI between 20 and 25 and obesity was defined as a BMI above 30. Dementia was diagnosed in 350 participants of the study with 114 persons being diagnosed with possible dementia. The researchers found that participants who were diagnosed with either Alzheimer’s disease or vascular dementia had a greater than 70% chance of being overweight in midlife. These new results add to the already existing evidence that carrying extra weight earlier in life can predispose an individual for the development of cognitive decline later in life. For the first time, these results also suggest that just being overweight in midlife also carried an independent risk for the development of dementia in later life. The exact cause or mechanism involved is not entirely clear but most likely results from the added risk of developing diabetes, high blood pressure, and increased cholesterol levels with obesity. The authors also add that other early life environmental exposures and genetic factors contribute to the development of dementia in the study participants. This study is particularly relevant as the world in now experiencing an obesity epidemic. The study has estimated that there at 1.6 billion people that are overweight in the world today. In the United States, a whole generation of baby boomers are preparing for retirement. This study can help predict which of those baby boomers carry an increased risk of developing dementia in their golden years.
W.L. Xu, A.R. Atti, M. Gatz, N.L. Pedersen, B. Johansson, and L. Fratiglioni (2011) “Midlife overweight and obesity increase late-life dementia risk: A population-based twin study” Neurology 76:1568-1574.