To understand the early changes, the researchers collected blood samples from 56 people with mild cognitive impairment (MCI) over several years. Although not all people with MCI go on to develop Alzheimer’s disease, people with the disease are diagnosed at a much higher rate than the general population. Of the 56 study participants, 36 were diagnosed with Alzheimer’s disease.
By examining how blood affects brain cells, the researchers made several important discoveries. Blood samples from participants who later deteriorated and developed Alzheimer’s disease contributed to reduced cell growth and division and increased apoptotic cell death (the process by which cells are programmed to die). However, the researchers noted that these samples also increased the conversion of immature brain cells into hippocampal neurons.
While the underlying causes of increased neurogenesis remain unclear, researchers think it may be an early compensatory mechanism for the neurodegeneration (loss of brain cells) experienced by people with Alzheimer’s disease.
When the researchers used blood samples collected only by the time participants were diagnosed with Alzheimer’s, they found that changes in neurogenesis occurred 3.5 years before the clinical diagnosis.
News cannot be equated with a doctor’s prescription. Consult an expert before making a decision.