The link between obesity and Alzheimer’s has been established before, but new data explains exactly how being overweight affects brain health.
Obesity is linked to several health conditions, including cardiovascular disease, diabetes, hypertension, depression and even cancer.
It has also been shown to greatly increase the risk of developing Alzheimer’s and other forms of dementia, particularly in older adults.
It wasn’t really known why obesity affects the brain, only that it does. Until now.
Researchers from Canada’s McGill University demonstrated in a study that someone who is obese loses grey matter brain cells in much the same pattern as someone with Alzheimer’s.
That’s because the body is unable to properly oxygenate the blood. Over time, a lack of blood going to the brain starts the process of neurodegeneration, which is a breakdown of neurons.
This breakdown of neurons is exactly what happens in Alzheimer’s patients.
Dr Filip Morys, lead author of the study, told Medical News Today he was prompted to conduct the study after seeing research that had found similar patterns of neurodegeneration between obese people and those with Alzheimer’s.
“It was known previously that obesity is a risk factor for Alzheimer’s disease, but we wanted to directly compare brain atrophy patterns in both, which is what we did in this new study,” he said.
“At this point, our study suggests that obesity prevention, weight loss, but also decreasing other metabolic risk factors related to obesity, such as type 2 diabetes or hypertension, might reduce the risk for Alzheimer’s disease and have beneficial effects on cognition.”
The McGill study solidified previous examinations of the relationship between Alzheimer’s and body weight.
Another study, published in The Journal of Alzheimer’s Disease Reports, underscores the impact that being overweight in midlife can have on brain health in older age.
Lead author of that study, Professor Annalena Venneri from the University of Sheffield, says waiting until your 60s to lose weight is too late.
“The diseases that cause dementia, such as Alzheimer’s and vascular dementia, lurk in the background for many years,” Prof. Venneri told Timesnownews.com.
“It is important to stress this study does not show that obesity causes Alzheimer’s, but what it does show is that being overweight is an additional burden on brain health and it may exacerbate the disease.
“Prevention plays such an important role in the fight against the disease.”
Researchers from the Universities of Sheffield and Eastern Finland studied MRI brain scans from 47 patients diagnosed with mild Alzheimer’s, 68 patients with mild cognitive impairment and 57 cognitively healthy individuals, Timesnownews reported.
The study used three complementary, computational techniques to map the brain, its fibres and blood flow. Scientists compared those images and measured grey matter volume, white matter integrity, cerebral blood flow and obesity.
In mild dementia patients, a positive association was found between obesity and grey matter volume around the right temporoparietal junction.
With growing evidence that weight loss later in life can be an early warning sign of Alzheimer’s, researchers also found that anyone with mild Alzheimer’s should try to maintain a healthy weight.
“Weight loss is commonly one of the first symptoms in the early stages of Alzheimer’s disease as people forget to eat or begin to snack on easy-to-grab foods like biscuits or crisps, in place of more nutritional meals,” said joint study author Dr Matteo De Marco.
“People don’t often think about the importance of nutrition in relation to neurological conditions, but these findings show it can help to preserve brain structure.”
Dementia Australia counts high cholesterol, type 2 diabetes and obesity as major contributors to dementia.
Is Alzheimer’s a concern for you? Have you had experience of a loved one with Alzheimer’s or dementia?