A slow, chronic starvation of the brain as we age appears to be one of the major triggers of a biochemical process that causes some forms of Alzheimer's disease.

A new study from Northwestern University's Feinberg School of Medicine has found when the brain doesn't get enough sugar glucose -- as might occur when cardiovascular disease restricts blood flow in arteries to the brain -- a process is launched that ultimately produces the sticky clumps of protein that appear to be a cause of Alzheimer's.

Robert Vassar, lead author, discovered a key brain protein is altered when the brain has a deficient supply of energy. The altered protein, called elF2alpha, increases the production of an enzyme that, in turn, flips a switch to produce the sticky protein clumps. Vassar worked with human and mice brains in his research.

A team at U Rochester is chasing down what they think is a mechanism by which poor circulation turns on two proteins which block the removal of toxic amyloid beta.