High Fat Diets and Dementia

Your brain is made up of millions of brain cells, each of which is primarily made up of fat. As a matter of fact, 70% of your nerve cells are made from lipids, or fats. Thus, it just makes sense that to make more brain cells, i.e. to boost your memory, you must eat fat.

You may have been told to not eat a lot of fatty foods. If so, you’re not alone. Most nutritionists and government backed agencies have hammered into our brains the concept of “low-fat” is good. Manufacturers have picked up on this and now we have a plethora of foods that are low-fat. But is the low-fat diet the right diet to do?

Recent studies have overwhelmingly favored high-fat diets over low-fat diets due to reductions in health-related problems.[1]One type of high-fat diet is the ketogenic diet, where your body metabolizes fat for fuel resulting in formation of ketones within your blood, which can also be used for fuel.

Ketogenic diets provide many health improving benefits. For one, they can protect your brain, or what we call neuroprotection. Eating such a diet with more fatty foods rich in essential fatty acids has been shown to decrease your risk of developing age-related diseases such as Alzheimer’s disease (AD)and Parkinson’s disease (PD).[2]Moreover, maintaining a state of ketosis is actually good for your brain and could decrease your risk of developing these dementia disorders.[3]

Dementia and Alzheimer’s disease are degenerative diseases of aging that are caused by multiple  problems as we age, including damage from three process that occur as we age: 1) cellular damage from development of free radicals produced naturally as “by-products” of life; also called reactive oxygen species or ROS, 2) Increased inflammation, which can damage tissues, and 3) Reductions in the energy produced by the mitochondria within the brain cells.

Ketogenic diets improve all three of these problems that occur with aging. They decrease the production of ROS within the brain cells.[4]  Mitochondrial function is improved because they increase energy reserves within the cells. Plus, brain cells like to use ketones for their fuel even better than they use glucose. When you’re in a state of ketosis, insulin levels also fall, and high insulin levels may be toxic to brain cells. Thus, less insulin, less damage to brain cells.

Ketogenic diets also have been shown to exhibit protective anti-inflammatory effects on the brain.[5]Inflammation of the brain cells include activation of inflammatory cells between neurons in the brain. These are called microglia and they produce compounds that cause inflammation (such as certain cytokines) that can damage brain cells with subsequent degeneration of the cells. Stress-induced behavioral and inflammatory responses appear to be reduced when ketosis is present.[6]

A problem found in AD is reduced ability to utilize glucose,[7]This may be partly the cause of why energy production is reduced in such brain cells.[8]This reduced energy production has been strongly linked to the progression of cognitive decline and degeneration seen in AD. Such abnormal metabolism may even be the reason why AD brain cells accumulate and produce the abnormal amyloid-β protein which is so characteristically seen in AD.[9]

Ketogenic diets change this. Brain cells don’t need to utilize glucose for fuel any longer while on this diet because they can use ketones instead. Ketone bodies are an effective alternative energy source for the brain’s fuel. When plasma ketones are elevated, cognitive function in older adults with memory disorders improves, including those with Alzheimer’s disease. Thus, just changing the brain’s metabolism via ketosis can be beneficial for cognitive dysfunctions from age-related dementias.

High fat ketogenic diets, through activation of a complex microsystem (called PPAR pathway) by ketosis can inhibit the activation of those inflammatory microglial cells. This decreases inflammation and the deposition of β-amyloid on the nerve cells and decrease mitochondrial oxidative stress; many of the pathologic problems that occur with AD. [10]

Through these many protective actions, ketogenic diets can thus provide a very viable pathway to help you reduce your risk of developing Alzheimer’s disease. [11]In addition, they may improve AD if you have it.[12]Essentially, low glucose uptake into the brain cells results in ineffective production of energy (glycolysis) and results in cognitive degeneration. The brain cells are starving. This is especially seen in diabetic patients where insulin resistance prevents the cells from bringing in glucose into the brain cells with resultant blunting of cognition.

Many case reports have shown improvement of Alzheimer’s disease when adequate ketosis in the brain is present.[13]For instance, one study in the magazine Alzheimer’s Dementia in 2016[14]demonstrated that producing hyperketonemia can actually help people who have Alzheimer’s disease. They induced ketosis in a patient with worsening Alzheimer’s disease. Over several months, he began accomplishing more complex tasks, his conversational abilities improved, and had modest improvement in cognitive abilities.

Another action that ketones do to the brain is to help you think more clearly. Just think, if you don’t have to rely on glucose to provide the energy for brain function and instead you utilize ketones for your brain food, which brain cells like better resulting in you maintaining a more alert mental state. You thus can think more clearly. Using ketones for your brain food has been associated with improved learning and memory abilities. In addition, more blood goes to the brain also improving your thinking capabilities.[15]

In conclusion, high fat diets, or ketogenic diets, are good for your brain. They can help decrease your risk of developing dementias, such as Alzheimer’s disease, and they can help you think clearer with better mental focus.



[1]Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med, April 2013;368(14):1279-1290 . DOI:10.1056/NEJMoa200303.

[2]Gosior M, Rogawski MA, Hartman AL. Neuroprotective and disease-modifying effects of the ketogenic diet. Behav Pharmacol. 2006 Sep; 17(5-6): 431–439. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2367001/

[3]Reger MA, et al. Effects of beta-hydroxybutyrate on cognition in memory-impaired adults. Send to

Neurobiol Aging. 2004 Mar;25(3):311-4. https://www.ncbi.nlm.nih.gov/pubmed/15123336

[4]Maalouf, M.; Rho, J.M.; Mattson, M.P. The neuroprotective properties of calorie restriction, the ketogenic diet and ketone bodies. Brain Res. Rev. 2009, 59, 293–315. https://www.ncbi.nlm.nih.gov/pubmed/18845187

[5]Koppel, S.J.; Swerdlow, R.H. Neurochemistry International Neuroketotherapeutics: A modern review of a century-old therapy. Neurochem. Int. 2017. https://www.science.Indirect.com/science/article/pii/S0197018617302279

[6]Yamanashi T, et al. Beta-hydroxybutyrate, an endogenic NLRP3 inflammasome inhibitor, attenuates stress-induced behavioral and inflammatory responses. Scientific Reportsvolume 7, Article number: 7677 (2017). https://www.nature.com/articles/s41598-017-08055-1

[7]Op Cit. Reger MA. https://www.ncbi.nlm.nih.gov/pubmed/15123336

[8]Swerdlow, R.H. Brain aging, Alzheimer’s disease and mitochondria. Biochim. Biophys. Acta-Mol. Basis Dis. 2011, 1812, 1630–1639. https://doi.org/10.1016/j.bbadis.2011.08.012

[9]Wilkins, H.M.; Swerdlow, R.H. Amyloid precursor protein processing and bioenergetics. Brain Res. Bull. 2017, 133, 71–79. https://doi.org/10.1016/j.brainresbull.2016.08.009

[10]Op cit. Tyagi S. doi: [10.4103/2231-4040.90879]

[11]McDonald TW, Cervenka MC. The Expanding Role of Ketogenic Diets in Adult Neurological Disorders. Open Access. Brain Sci. 2018, 8(8), 148; doi:10.3390/brainsci8080148

[12]Taylor MK, et al. Feasibility and efficacy data from a ketogenic diet intervention in Alzheimer’s disease. Alzheimers Dement (N Y). 2017 Dec 6;4:28-36. doi: 10.1016/j.trci.2017.11.002

[13]Henderson ST, Vogel JL, Barr L, Garvin F, Jones JJ, Costantini LG. Study of the ketogenic agent AC-1202 in mild to moderate Alzheimer’s disease: a randomized, double-blind, placebo-controlled, multicenter trial. Nutrition & Metabolism. 2009;6:31. doi: 10.1186/1743-7075-6-31.

[14]Newport MT, et al. A new way to produce hyperketonemia: use of ketone ester in a case of Alzheimer’s. Alzheimers Dement. 2015 Jan; 11(1): 99–103. Oct 2014.. doi:  [10.1016/j.jalz.2014.01.006]

[15]Xu, K.; Sun, X.Y.; Eroku, B.O.; Tsipis, C.P.; Puchowicz, M.A.; Lamanna, J.C. Diet-induced ketosis improves cognitive performance in aged rats. In Oxygen Transport to Tissue XXXI; Springer: Boston, MA, USA, 2010; Volume 662, pp. 71–75. https://link.springer.com/chapter/10.1007/978-1-4419-1241-1_9