New research out of UT Health San Antonio suggests that obesity in middle-age might be linked to the development of Alzheimer's Disease in later years.
Claudia Satizabal, Ph.D, at the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases is a corresponding author on a study that found that 21 genes related to Alzheimer’s appear to behave differently in people who were obese in their forties and fifties, particularly women. They studied genetic information from participants in the Framingham Heart Study.
“We saw that obesity was associated with an upregulation or activation of certain risk genes for Alzheimer's disease, as well as the activation or downregulation of protective genes,” Satizabal said.
That means genes linked to the development of Alzheimer's disease were more active, and those that may protect against it were less active.
Satizabal became curious about a possible genetic link between obesity and Alzheimer's after prior epidemiological studies suggested midlife obesity may be a factor in Alzheimer’s disease risk in women.
The Framingham Heart Study, which began studying cardiovascular disease in 1948, now includes three generations of participants. She wondered, if she and her team identified participants in the study who had gene variants that increase the risk of developing Alzheimer's disease, could they confirm a link with obesity in midlife?
Satizabal's team analyzed people with 74 Alzheimer's related genes and confirmed a link in 21 of the genes.
Researchers also found that while there was a connection between the development of Alzheimer's and a high body mass index — BMI — the correlation was even stronger in people with high waist-to-hip ratios, meaning more excess belly fat.
“So (high waist-to-hip ratio) seems to be a more sensitive marker of metabolic dysregulation and it has stronger correlations with the regulation of genes,” Satizabal noted.
What Satizabal and her team have found is evidence of a correlation between obesity in midlife, not causation. She is not saying that obesity causes Alzheimer's but that perhaps something or more than one thing that are factors in the development of both are at play, here. Or, perhaps, obesity is part of a biological cascade that can end in the development of Alzheimer's disease.
"Obesity tends to cluster with many metabolic diseases like diabetes, hypertension," Satizabal pointed out. "So all that, we know, is very bad for the brain and the brain vasculature. So this contributes, I think, to an environment of malfunction that adds and exacerbates any potential degeneration already ongoing."
"So that is just not helping anything," she added.
Satizabal concluded that maintaining a healthy weight through middle-age is an important factor in healthy aging, particularly for women.
“You need to really start taking care of yourself in midlife," Satizabal said. "That will pay big benefits later on for your brain.”
Because this study relies on information gather from the Framingham Heart Study, it is limited in scope because most of the participants in that study are of European descent.
Researchers at the Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases hope to broaden the pool of research participants to include those of other ethnicities, particularly those of Latino descent.
People from all backgrounds who would like to participate in clinical trials or other research can sign up for more information here.
