A new study has determined that brains of people in their 20s can show the characteristics of Alzheimer’s disease, with amyloid plaques accumulating. The findings of the study were published in the journal Brain. The age of onset has previously been associated with occurring in older people, after the age of 60, and it’s estimated that 5 million people in the U.S. are living with the disease.
The research study consisted of examining the brain cells in three groups of deceased people: 13 people aged 20-66 who were cognitively normal when they died, 16 people aged 70-99 who did not have dementia when they died, and 21 people aged 60-95 who had Alzheimer’s disease when they died. The specific group of brain cells that were of interest are referred to as basal forebrain cholinergic neurons. These brain cells are closely involved in memory and attention and are among the first to die in normal aging and in Alzheimer’s disease.
The findings revealed that amyloid protein began accumulating in neurons in young adulthood and continued throughout the lifespan. None of neurons in other parts of the brain revealed the same extent of amyloid accumulation. It was also determined that amyloid clusters inside brain cells may contribute to amyloid plaques outside cells.
The researchers attribute the development of Alzheimer’s disease characteristics to a lifelong accumulation of amyloid in vulnerable neurons likely contributing to cell death, clumping and the formation of plaques inside and outside of the neuronal cells.
“Discovering that amyloid begins to accumulate so early in life is unprecedented”, said Changiz Geula, a research professor at Northwestern University Feinberg School of Medicine’s Cognitive Neurology and Alzheimer’s Disease Center. “This is very significant. We know that amyloid, when present for long periods of time, is bad for you.”
Neuronal amyloid-β accumulation within cholinergic basal forebrain in ageing and Alzheimer’s disease, Alaina Baker-Nigh, et al., Brain, doi:10.1093/brain/awv024, published online 2 March 2015, abstract.