Unexplained weight loss may be a possible early sign of Alzheimer's disease

What is it about?

Lesions that develop and accumulate in the brain can impair cognitive function and lead to dementia, as is commonly seen in Alzheimer’s disease, the most frequent cause of dementia worldwide. Interestingly, up to 20% of people with normal cognition (those who don’t show clear signs of brain impairment) are found to meet the criteria for one or more neuropathological diagnoses when their brains are examined after death. This suggests that these brain lesions gradually accumulate over time, eventually leading to a dementia diagnosis. Another well-known observation is that people with dementia often experience weight loss, leading to a lower body mass index (BMI) compared to healthy individuals. However, emerging research shows that weight loss can also occur in people with normal cognition, even before the onset of cognitive symptoms. This raises the possibility that weight loss may be an early sign of dementia-related changes in the brain. Our study aimed to explore the connection between dementia-related brain lesions and BMI by examining the brains of individuals during autopsies.

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Photo by Kenny Eliason on Unsplash

Photo by Kenny Eliason on Unsplash

Why is it important?

Our study found a link between brain lesions characteristic of Alzheimer’s disease and lower BMI, not only in individuals with cognitive symptoms but also in those with normal cognition. More importantly, our analysis suggested that weight loss is associated with the presence of brain lesions independent of the cognitive symptoms they cause. This means that unexplained weight loss in older adults could be an early sign of the buildup of Alzheimer’s disease-related brain lesions, even before cognitive symptoms appear. This insight may lead to earlier detection, diagnosis, and ultimately, more effective treatments in the future.