Scientists at the University of Washington, Seattle, raised blood insulin in 16 healthy seniors and then examined the volunteers’ cerebrospinal fluid and plasma.
The investigators found that the rise in insulin precipitated increases in the subjects’ inflammatory markers and beta-amyloid, a protein associated with the formation of plaque on the brains of Alzheimer’s patients.
The researchers speculate that conditions involving insulin-resistance – including diabetes, hypertension, obesity, cardiovascular disease and glucose intolerance – may increase the risk of Alzheimer’s.