If you pay attention to diet trends, you’ve likely heard of—or maybe even tried—the keto diet.
The ketogenic diet involves eating a high percentage of fat and few carbohydrates. This forces the body into a metabolic state called ketosis, which involves burning fat for energy instead of glucose. The diet also leads to lower blood sugar and insulin levels.
While the keto diet may seem like a fad now, it was first introduced in the 1920s as a treatment for epilepsy in children, and there is clear evidence that it’s an effective treatment.
Researchers are also investigating the keto diet as a treatment for Alzheimer’s disease. They’ve already established that Alzheimer’s disease decreases the brain’s ability to use glucose. Studies have found the brain’s ability to metabolize glucose is impaired up to 15 years before the onset of the clinical symptoms for Alzheimer’s disease. Preliminary evidence suggests the keto diet could provide an alternate source of energy—ketone bodies—as a source of brain fuel.
A systematic review published recently in the journal Frontiers in Neuroscience looked at the effects of the keto diet on people with Alzheimer’s disease at both the molecular level and in cognitive assessments.
Alzheimer’s disease leads to a buildup of plaques—called amyloid beta—in the brain. Researchers found that the keto diet helps to move these plaques across the brain’s protective barrier, which can reduce plaque deposits in the brain.
The review also found evidence that the keto diet reduces markers of dysfunction for astrocytes, star-shaped cells in the brain that help provide brain cells with electrolytes and energy and assist in repairing damage. It found the keto diet helps to reduce levels of neurofilament light chain, a biomarker typically present when there is neuronal damage in the brain. And it summarized studies that show the keto diet reduces inflammation and oxidative stress throughout the body, which are both related to Alzheimer’s disease.
Most importantly, studies found improvements in cognitive performance for people following the keto diet. These include improvements in memory, executive function, and processing speed. Improvements were most pronounced in people with mild cognitive impairment, a precursor to Alzheimer’s disease.
Although the keto diet shows promise in helping to address Alzheimer’s disease, the study authors note that more research is needed to determine whether the diet is effective in preventing the progression of Alzheimer’s disease.
It’s also important to note that the keto diet can lead to health problems, especially for people at an increased risk for heart disease.
”One of the most important things scientists have learned about Alzheimer’s disease is that disease processes begin decades before people show cognitive symptoms,” said Elizabeth Riley, a neuroscience postdoctoral researcher in the Department of Psychology at the College of Human Ecology at Cornell University. “Once symptoms appear, the brain has already sustained irreparable damage. Coming to terms with this means we must focus on disease prevention. This kind of research helps us understand how what we eat may have the power to change our cognitive aging trajectory over many years.”
The take-home message: The keto diet shows some promise in helping to stop the progression of Alzheimer’s disease, but more research is needed before it can be used as a standard treatment.
