Are low carbohydrate diets bad for the brain?
Ketogenic diets (low carbohydrate diets) promote the increased use of ketone bodies–soluble compounds produced by the body when fatty acids are broken down–by the brain. But, is this safe?
When examining epileptic children who spend years in ketosis, or the accumulation of higher than normal ketone bodies, there seems to be no negative effect on cognitive function, except fatigue in the beginning stages of the diet (Hale, 2010). In addition, ketogenic diets are used as treatment for some diseases. Klepper and colleagues (2003) reported that ketogenic diets have been used for decades to treat intractable childhood epileptics, but they can also be used for treating other conditions such as glut 1 deficiency syndrome and pyruvatedehydrogenase-complex-deficiency.
Reger and colleagues (2004) suggest that beta-hydroxybutyrate (a ketone body) may improve cognitive functioning in older adults with memory disorders such as Alzheimer’s disease and mild cognitive disorders.
Furthermore, Veech (2004) says, “Mild ketosis may offer therapeutic potential in a variety of different common and rare disease states.” These disorders include diseases due to insulin resistance or substrate insufficiencies, diseases due to free radical damage, and diseases due to hypoxia. Some studies have also shown that ketogenic diets can be used in the treatment of Parkinson’s disease and brain tumors.
Currently, there is a fair amount of research being conducted on low carb diets and their benefits for various neurodegenerative disorders.
Ketogenic diets have been used as treatment for a wide array of disorders. At this point evidence does not suggest that ketogenic diets are harmful to the brain. However, more long-term research needs to be conducted in this area. Ketogenic diets work well for some people while they are hell for others. If you feel bad while following a low carbohydrate diet, switch diets.
Additional Key Points
- After adaptation, the brain can derive up to 75% of its total energy requirements from ketone bodies.
- A primary role of ketone bodies is to replace glucose as a fat-derived fuel for the brain.
- Some people experience mental fatigue and a decrease in concentration while following ketogenic diets. This is especially true for the first 1-3 weeks of the diet.
- Much more research regarding low carb diets and brain functioning needs to be done with various populations.
Hale, J. (2010). Should I Eat the Yolk? Separating Facts From Myths To Get You Lean, Fit and Healthy. Berkeley, CA: Ulysses Press.
Klepper J, et. al. (2003). The Ketogenic Diet in German-speaking Countries: Update. Universitats-kinderlinik Essen.
Reger MA, et. al. (2004). Effects of betahydroxybutyrate on cognition in memory-impaired adults. Neurobiology of Aging 25(3):311-314.
Veech RL. The therapeutic implications of ketone bodies: the effects of ketone bodies in pathological conditions: ketosis, ketogenic diet, redox states, insulin resistance, and mitochondrial metabolism. Prostaglandins Leukot Essent Fatty Acids 70(3):309-19 Review.
Photo by Ali Karimian, available under a Creative Commons attribution license.