Fructose, a natural sugar found in fruits and honey—and in an array of soft drinks and processed foods—may lie at the root of Alzheimer’s Disease, according to researchers at the University of Colorado.

When food is scarce, the brain focuses more of its energy on spotting and grabbing something to eat. To get that extra power, the brain takes energy away from the hippocampus and cerebral cortex—parts of the brain involved in social behavior, self-control, creating memories, and processing language, among other things.

When the need to eat has been satisfied, the brain sends energy back to those parts of the brain where higher-order skills are housed and people can speak, socialize, and create new memories.

Turns out that switching off those temporarily less important parts of the brain is a process triggered by fructose. 

This natural sugar sets off a process that cuts back blood flow to the hippocampus and cerebral cortex and sends more blood to the eyes so they can sharpen their focus on spotting the next meal.

Problem: for decades, fructose made in factories has been a cheap substitute for cane sugar in soft drinks and other sugary processed foods.

Many of us have been chugging fructose steadily for years.

“Chronic and persistent reduction in cerebral metabolism driven by recurrent fructose metabolism leads to progressive brain atrophy and neuron loss with all of the features of Alzheimer’s Disease,” study leader Dr. Richard Johnson told Science.

The “fructose switch” that focused our earliest ancestors on the hunt for food in times of famine may now be stuck in the “on” position, he said.

“A study found that if you keep laboratory rats on fructose long enough they get tau and amyloid beta proteins in the brain, the same proteins seen in Alzheimer’s disease,” Johnson said. “You can find high fructose levels in the brains of people with Alzheimer’s as well.”

The tendency of Alzheimer’s patients to wander might be a vestige of this primordial drive to find food, the study report suggested.

TRENDPOST: Factory-made fructose, especially high-fructose corn syrup, also has been linked to obesity, diabetes, and high levels of triglycerides in the blood.

Food labels are your friends. The next time you see a drink or manufactured food that lists fructose among the ingredients, put it back on the shelf.