A gradual loss of blood flow to the brain over years or decades could be a major trigger for Alzheimer’s disease, according to a study. Up till now, the cause for this disease has remained a mystery, even if the mechanism causing the damage is well understood.

The new research shows that an insufficient supply of sugar glucose, transported by blood, sets off a biochemical chain reaction resulting in the accumulation of the neuron-attacking proteins that cause Alzheimer’s.

“This findings is significant because it suggests that improving blood flow to the brain might be an effective therapeutic approach for prevention or treatment of Alzheimer’s,” said Robert Vassar, a professor at North Western University’s Feinberg School of Medicine, and lead author of this study.

“Exercising, reducing cholesterol intake and managing hypertension are the measures that could provide added protection”, he said. “For persons who already show symptoms of constricted arteries, taking vasodilators (drugs that boost blood flow) could help deliver nourishing oxygen and glucose to the brain,” he added.

Drawing from experiments with humans and mice, Vassar and colleagues showed that reduced blood flow alters a protein called elF2alpha. In its changed form, elF2alpha increases the output of the enzyme that spurs production of the fiber-like knots of amyloidal beta protein that form outside neurons and disrupt their ability to send messages.

The finding published in the journal Neuron could lead to drugs designed to block the elF2alpha production that begins the formation of the protein clumps, also known as amyloid plaques, Vassar added.

Alzheimer’s disease is incurable and is the most common form of dementia among older people. It affects the regions of the brain involving thought, memory and language.

Source: TOI