The obesity epidemic seen in the United States has been studied extensively over the years. One truly intriguing finding some scientists have discovered is the link between obesity and cognitive decline.

A paper published in The Lancet by Dr. Amanda Kiliaan and colleagues discussed the association between being obese over a lifetime and the risk for brain atrophy, white matter deterioration, late-onset dementia, and Alzheimer’s disease. The researchers began by considering how a high body-mass index could cause dementia and the decline of the brain matter.

The increase in adipose tissue, specifically adipose tissue hormones and adipokines, could be tied to the rise in Alzheimer’s disease and dementia risk in obese patients. However, hundreds of adipokines have been identified, which makes it more difficult to narrow down the possible cause of dementia within the overweight population. Adipokines have been studied in clinical dementia trials, imaging-based analysis of brain volume, and in pre-clinical models of cognitive decline.

Other hypotheses link the vascular risk factors related to obesity as a potential contributing factor to dementia and Alzheimer’s disease. A study published in JAMA Neurology by researchers from the Karolinska Institute in Stockholm, Sweden looked into the connection between body mass index, vascular factors, and subsequent dementia.

The researchers followed up with subjects from a prior clinical trial after 21 years. The average age range of the patients was between 50 to 71 years of age. The patients were given a questionnaire to fill out about their health habits and medical history. Blood specimens were taken to measure cholesterol levels. Systolic and diastolic blood pressure data was also taken after the subjects sat still for five minutes. Height and weight was measured to determine the subjects’ body-mass index ratio.

It was found that obesity at midlife was linked to a higher risk in Alzheimer’s disease and dementia when compared with subjects at a standard, healthy weight. Additionally, high systolic blood pressure and high cholesterol levels were also associated with cognitive deterioration. Each of these factors increased the likelihood of dementia by two times.

Along with these major findings, the clustering of vascular risk factors showed another correlation to dementia. The researchers had looked at whether vascular risk factors can independently or in clusters influence a rise in risk of dementia or Alzheimer’s disease. Clearly, losing weight or staying at a healthy body-mass index ratio is important for preventing senility, especially due to the rising rates of obesity across the globe.

This isn’t the first study to find a rise in BMI linked to dementia. The Honolulu-Asia Aging Study and another clinical trial from Sweden discovered similar findings. Research on the obesity epidemic, especially drug development, does not start directly in clinical trials but must first be studied in animal models to ensure certain agents are relatively safe for use in humans.

For example, one study conducted by researchers in Japan used mouse models to analyze neurodegeneration and obesity. Another discovery found that with the rise in obesity, the risk of type II diabetes increases and damages blood vessels, which may lead to diabetic dementia, according to the Health Day publication. Through the use of animal models, the scientific community may discover a variety of causes for neurological decline.

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Categories: Obesity

Tags: alzheimer's disease, dementia, mouse models, obesity, pre-clinical models