Evolutionary Foraging Instinct May Increase Risk of Developing Alzheimer’s Disease
Researchers at the University of Colorado Anschutz Medical Campus have discovered that an evolutionary foraging instinct, fueled by fructose production in the brain, may be the underlying cause of Alzheimer’s disease (AD). This foraging response was initially beneficial, allowing humans to survive periods of scarcity. However, in a time of relative abundance, this response causes overeating of high-fat, sugary, and salty foods, leading to excess fructose production and ultimately increasing the risk of developing Alzheimer’s disease.
The study, published in The American Journal of Clinical Nutrition, suggests that Alzheimer’s is a negative variant of a survival mechanism used by animals and our distant ancestors during times of food shortage. Fructose, a type of sugar found in honey, fruit juices, some vegetables, and some fruits, helps damp down centers in the brain, allowing more focus on food gathering.
“We make the case that Alzheimer’s disease is driven by diet,” said the study’s lead author Richard Johnson, MD, professor at the University of Colorado School of Medicine. “It results from a maladaptation to an evolutionary survival pathway that is used by many animals and was even essential to the survival of our distant ancestors millions of years ago.”
In addition to food containing fructose, Johnson and his team suggest that glucose, high glycemic index foods, and salty foods can also increase the levels of fructose in the brain. This, combined with the uric acid produced after the breakdown of fructose in the periphery, can stimulate the production of fructose in the brain.
The researchers suggest that both dietary and pharmacologic trials to reduce fructose exposure or block fructose metabolism should be performed to determine if there is potential benefit in the prevention, management or treatment of this disease. Johnson also suggested that the inclination of certain AD patients to wander off could be a remnant of the prehistoric foraging reaction.
To confirm their hypothesis, the team noted that patients with Alzheimer’s disease had higher levels of a certain type of sugar in their brains. Moreover, they have also shown higher levels of enzymes and metabolites associated with fructose metabolism in the brains of individuals with Alzheimer’s. Individuals with mild cognitive impairment or dementia have higher levels of uric acid in their cerebrospinal fluid.
0. “Study: Ancient Foraging Instinct Could Hold Alzheimer's Clues” Laboratory Equipment, 15 Feb. 2023, https://www.laboratoryequipment.com/594496-Study-Ancient-Foraging-Instinct-Could-Hold-Alzheimer-s-Clues/
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