Growing evidence has shown that obesity is linked to memory and concentration issues. Some studies show that losing weight can improve memory function, providing further evidence of the benefits of reaching and maintaining a healthy weight. Previous research has shown that obese people have impaired episodic memory, the memory of events that happen throughout one’s life.
Obesity in America is a significant concern, with over 36% of adults being considered obese by BMI standards. The findings of one study also suggest that besides impacting episodic memory, “people who are overweight may experience memory slightly less vividly or in less detail,” said lead researcher Lucy Cheke, a lecturer in the department of psychology at the University of Cambridge in England,
A new study used functional magnetic resonance imaging (functional MRI) to track brain activity while test participants performed a memory test. Their goal was to better understand whether improved memory correlated with changes in relevant brain activity. The test subjects were 20 overweight, postmenopausal women and they were divided into two groups that consumed different, healthy weight loss diets for six months.
The test subjects were tested in their episodic memory (the collection of experiences specific to a place and time) by having them memorize names and faces during the functional MRI. Later, they were told to recall the first letter of the name that was associated with the face. After weight loss, researchers found that memory function had improved- supported by brain activity patterns that were observed during the functional MRI. One researcher explained the increased brain efficiency, “The altered brain activity after weight loss suggests that the brain becomes more active while storing new memories and therefore needs fewer brain resources to recollect stored information,” he said.
This evidence is supported by other studies that also show that losing weight changes how the brain works. Diet related weight loss is associated with decreased levels of plasma free fatty acids (FFA), and episodic memory linked to increased hippocampal activity (which is largely responsible for memory and learning). FFAs may impact insulin signaling and secretion from the pancreas and can lead to the development of diabetes, a risk factor for heart failure. This is one reason that weight loss decreases risks associated with diabetes such as heart disease, stroke, high blood pressure, and more.
Addressing obesity important to ward off risk factors
The promising aspect of these findings is that increased brain function and improved memory occurred after weight loss. This means that brain function associated with obesity can be reversed. The risk to the brain and memory function isn’t only in the immediate; studies have shown that people that are obese even as young as in their 40s+ have a higher risk of dementia later in life. A study carried out by Ranjana Mehta, an assistant professor of environmental and occupational health at the Texas A&M Health Science Center School of Public Health in College Station, Texas, notes obesity can change the structure of the brain and cause atrophy.
Research released in March 2022 has also found significant data that ties gut health to the development of Alzheimer’s disease (which is the leading cause of dementia). Other studies have explored the connection between obesity, inflammation, and Alzheimer’s disease. We already know that inflammation is prevalent in those with obesity. The new studies that explore the gut health of those with Alzheimer’s found that study participants had higher levels of inflammation markers in their stool and blood. This, paired with evidence from studies shared last year that showed that inflammation in the brain promotes changes that lead to the onset of dementia and Alzheimer’s disease, suggests that inflammation as a result of what is consumed plays a significant role in brain health and memory, as it also does in weight management.
While more research needs to be done, there is significant evidence that supports that reaching and maintaining a healthy weight decreases many impactful risk factors and protects brain health and memory. Speak to your provider about your risk factors and if weight loss may help decrease any risk factors that may impact your individual health.