“Acceptance that Alzheimer’s disease is a lifestyle disease, little different from other age-related diseases, that is the sum of a lifetime is the most important breakthrough of the decade. Dr. Amen and collaborators provide compelling evidence that obesity alters blood supply to the brain to shrink the brain and promote Alzheimer’s disease. This is a major advance because it directly demonstrates how the brain responds to our body.”
– George Perry, PhD
Editor-in-Chief of the Journal of Alzheimer’s Disease
Semmes Foundation Distinguished University Chair in Neurobiology at The University of Texas at San Antonio
Many of us are familiar with the idea that being overweight and obesity puts stress on the body and contributes to poor health. Well it turns out that the brain is no exception to this rule.
Recent research indicates that body weight has a substantial influence on brain function.
For one, research indicates that as a person’s body mass index increases, it reduces cerebral blood flow. Reduced cerebral blood flow is associated with a number of major health problems including Alzheimers and psychiatric disorders including depression, ADHD, bipolar disorder, schizophrenia, traumatic brain injury, addiction, suicide, and other conditions.
Secondly, research on caloric restriction shows promise for increasing brain function, even in the elderly. For the first time ever, a study in 2016 showed improved recognition memory, paralleled by increased gray matter volume in inferior frontal gyrus and hippocampus, and augmented hippocampal resting-state functional connectivity to parietal areas as a result of weight loss due to reduced caloric intake.
Thirdly, another study found that a regime of physical exercise in overweight humans induces weight loss and improved metabolic and cognitive functioning, particularly in areas traditionally affected by overweight such as the temporal and parietal lobes, hippocampus, posterior cingulate gyrus, and precuneus insular cortex, and the left cerebellar regions.
Interestingly enough, even bariatric surgery for weight loss has been shown to result in increased cognitive health. Research shows those who underwent such a procedure showed global increase in white matter density and an increase in grey matter density in the occipital and inferior temporal regions.
All of this research seems to indicate that not only that being overweight is detrimental to brain health and cognitive function, but that weight loss and fitness are a vital part of mental wellness.
Prehn, K., Jumpertz von Schwartzenberg, R., Mai, K., Zeitz, U., Witte, A. V., Hampel, D., … & Flöel, A. (2017). Caloric restriction in older adults—differential effects of weight loss and reduced weight on brain structure and function. Cerebral cortex, 27(3), 1765-1778.
Mueller, K., Möller, H. E., Horstmann, A., Busse, F., Lepsien, J., Blüher, M., Stumvoll, M., Villringer, A., & Pleger, B. (2015). Physical exercise in overweight to obese individuals induces metabolic- and neurotrophic-related structural brain plasticity. Frontiers in human neuroscience, 9, 372. https://doi.org/10.3389/fnhum.2015.00372
Tuulari, J. J., Karlsson, H. K., Antikainen, O., Hirvonen, J., Pham, T., Salminen, P., … & Nummenmaa, L. (2016). Bariatric Surgery Induces White and Grey Matter Density Recovery in the Morbidly Obese: A Voxel‐Based Morphometric Study. Human brain mapping, 37(11), 3745-3756.
IOS Press. (2020). Body Weight Has Surprising and Alarming Impact on Brain Function. Neuroscience News. https://neurosciencenews.com/body-weight-brain-function-16770/?fbclid=IwAR3S58YHYkTq6pQ03VsVn-CL7iqsY7xYjhNVDnvFXHmTHWVzwYOt86B4tzE