Common sweeteners may play a causative role in Alzheimer’s disease. (Shutterstock)
The exact cause of Alzheimer’s disease, a form of dementia, is still under investigation, but a growing body of research suggests that a common sweetener, high-fructose corn syrup, may play a role in the disease. effect.
High fructose syrup lowers brain metabolism
High fructose corn syrup (HFCS), commonly used in the processed food and beverage industries, is made from cornstarch and is often used as a substitute for sucrose (table sugar) because it is cheaper and more shelf-stable.
A study published in June 2022 in the “Public Library of Science” found that mice fed HFCS from an early age had adverse changes in parts of the brain responsible for memory, emotion and nervous system function. Long-term consumption of HFCS leads to a long-term reduction in metabolism in these areas of the brain, leading to brain degeneration and cognitive decline that are typical features of Alzheimer’s disease.
A review of studies published in March 2023 in the American Journal of Clinical Nutrition also noted that fructose may reduce metabolism in areas of the brain involved in higher cognitive functions. The researchers speculate that increased fructose levels in the brain may increase the risk of Alzheimer’s disease.
They also highlighted that intake of glucose (a component of sucrose) and foods with a high glycemic index played a large role in increasing fructose levels in the brain. A 2017 Yale study found that fructose in the brain can be produced from glucose.
“We believe that Alzheimer’s disease is diet-driven,” review lead author Dr. Richard Johnson, a professor of renal disease and hypertension at the University of Colorado School of Medicine, said in a statement. He cites earlier research showing that feeding fructose to mice long enough in the lab led to the formation of tau and amyloid proteins in the brain, proteins associated with Alzheimer’s disease.
Johnson thinks it might be a mechanism called a “survival switch,” which normally helps the body survive when food is scarce, but gets stuck in the “on” position when food is abundant. This leads to overeating of foods that are high in fat, sugar, and salt, which promotes an excess of fructose.
He suggested that dietary and pharmacological trials should be conducted to examine whether reducing fructose or blocking fructose metabolism would be beneficial in the prevention, management or treatment of Alzheimer’s disease. Existing research on the role of fructose metabolism in the brain is still limited.
Why fructose increases diabetes risk
Fructose consumption has increased significantly due to the widespread use of HFCS in beverages and processed foods. This sweetener has been shown to cause negative health effects, especially diabetes.
“Studies suggest that type 2 diabetes may be a risk factor for Alzheimer’s disease and other types of dementia, such as vascular dementia.” Holds a PhD in Psychiatry from the University of Oxford, Alzheimer’s Association Science Program and Field Claire Sexton, senior director of the exhibition, told The Epoch Times.
This, she explained, may be due to increased risk factors for type 2 diabetes, which have also been shown to increase the risk of dementia. It could also be the result of hypoglycemia caused by chronically impaired glucose metabolism in the brain, which needs blood sugar for its energy.
In a double-blind experimental study at the University of California, Davis, researchers observed increases in liver fat in two groups of subjects who drank three HFCS-sweetened beverages per day, or three sugar-sweetened beverages, for just two weeks. Reduced insulin sensitivity.
This does not mean that eating fruit is bad for our health. Fructose is only harmful in excess, and fruit contains very little fructose compared to many processed foods. Fruits are also rich in nutrients and fiber that help maintain a balanced diet and promote good health.
The problem is the free sugars we consume – fructose, glucose and sucrose, including those added to food and beverages during commercial processing, which are separated from the original ingredients.
Evidence suggests that the health risks posed by sugar are related to excess dietary intake of free sugars and not to sugars that occur naturally in foods such as fruit and milk.
Is Alzheimer’s disease the third type of diabetes?
Scientists report a strong association between type 2 diabetes and Alzheimer’s, noting that Alzheimer’s is twice as common in people with diabetes. One popular theory is that Alzheimer’s may be a metabolic disorder, similar to type 2 diabetes, in which the body fails to process insulin properly.
Studies have shown that insulin plays a crucial role in brain function and that insulin resistance in the brain plays a role in cognitive decline.
A 2021 study published in Frontiers in Neuroscience found that hyperglycemia (high blood sugar) in diabetes can lead directly to high blood sugar in the brain. Hyperglycemia in the brain may allow the blood-brain barrier to adapt by reducing the passage of glucose needed for brain function. High blood sugar in the brain offers a plausible explanation for the well-documented link between Alzheimer’s disease and diabetes, the researchers concluded.
There is growing focus on the idea that Alzheimer’s disease may be a third type of diabetes. However, the idea has sparked debate over whether and how the disease actually arises.
Dr. Sexton said she does not consider Alzheimer’s to be diabetes and does not think their similarities explain the complexity of the two diseases.
“While studies have shown a link between insulin resistance and Alzheimer’s risk, even without excess glucose in the brain, Alzheimer’s disease can still be severe,” Sexton said.
Asked whether treating insulin resistance could reduce Alzheimer’s risk, she said it was currently being tested in clinical trials.
“In fact, last year at the Alzheimer’s Association International Conference, T3D Therapeutics reported promising interim results from their Phase 2 trial of T3D-959, designed to restore metabolic health in the brain by overcoming insulin resistance .”
For the English report, please see the English “Epoch Times”:Sugar in Processed Foods and Drinks Linked to Dementia; Experts Explain Possible Reasons。◇
Editor in charge: Li Fan