Ketogenic Diet and Dementia


The body experiences a multitude of changes as we age. Hairs gray, muscles weaken, bones shrink, and the lenses in our eyes become less elastic. It is also natural to experience cognitive changes such as memory loss as we age, but serious cognitive decline is not typical. Healthy brains retain the ability to make new connections as we age, and are able to access existing neuronal connections (in other words, our memory and overall ability to function should not be compromised).

Dementia is characterized by a loss of brain functioning to the point that it effects day to day life. Symptoms include memory loss - particularly of recent events, confusion around time and events, and changes in mood and behavior. The risk for developing dementia increases to 50% by the time we are 85 with Alzheimers being the most common type, effecting 1 in 3 people over age 85. Presently, there is no known cure for dementia, but new research is informing preventative measures that may lower the risk for developing the disease.

Preventative Lifestyle Choices

There is no known cure for dementia, but we do know that it is caused by a combination of factors, the most significant being old age as cited above. Genetics, environmental exposure to toxins, a family history of the disease and certain lifestyle choices like smoking, poor diet, and lack of activity can also increase risk. If you experience repeated head trauma, if your blood brain barrier is compromised, or if you have immune system dysfunction, you may also be at higher risk.

Having identified risk factors, disease prevention is the best way we can address the rising rates of dementia worldwide. It seems that what is good for your heart is also good for your brain: getting exercise, keeping cholesterol in safe ranges, eating well, an active lifestyle and not smoking will all help reduce the risk for dementia. In general, staying physically and mentally active will help maintain cognitive functioning and memory. Continue to learn new things, whether it’s through reading new books, learning an instrument, or traveling. Stay socially connected and engaged in your community. Not only will this help preserve a healthy brain, it also helps slow the progression of the disease if already diagnosed.

The Ketogenic Diet

Preventative medicine for dementia can also include diet. The ketogenic diet has been used to help treat epilepsy for decades, and researchers are now looking to see if its neuroprotective effects may also help lower the risk for dementia.

The ketogenic diet aims to reduce intake of carbohydrate while increasing intake of fats. Certain oils, vegetables, nuts, cheeses, and other fat rich foods are encouraged. This is all done with the intent of triggering a metabolic state called ketosis. In this state, the liver produces more ketone bodies - molecules derived from the breakdown of fat, which then become the main source of energy for the body. The diet is intended to help the body run more efficiently by burning fat rather than letting it sit in long term storage.


So how might a high fat diet help to address brain changes related to dementia? First, we have to talk a little science. The brain only makes up 2% of our body mass but requires 20-25% of our total energy to function properly- that’s a lot! As we age, blood flow in the body slows which in turn impacts the amount of glucose (i.e. blood sugar) and oxygen that is going to the brain. This is a problem because the mitochondria that live inside our neurons need glucose so that they can turn it into brain food (otherwise called ATP). In dementia, it is thought that the brain gets compromised by the reduced blood flow and by a disruption in the mitochondria’s ability to make energy for the cell and clean up after itself (get rid of the toxins that are produced during metabolism).

Dementia also interferes with the brains’ ability to send signals between neurons. Scientists believe, as is explained in the Ted Talk linked below, that Dementia compromises the brain’s ability to rid itself of certain proteins, ß-amyloid (A𝛽) and tau, eventually causing a buildup of these proteins in the form of neurofibrillary tangles (NFT, caused by tau) and amyloid plaques. Scientists believe that eventually neurons are no longer able to send signals to one another because of the plaque and NFT between them. When neurons can no longer communicate, they die. Another consequence of NFT and plaque is inflammation, a decline in mitochondrial functioning and metabolic dysfunction. If the brain does not get the energy it requires, disease sets in.

With a ketogenic diet, the body begins to use fat as its main fuel source instead of glucose. Reducing blood sugar levels can protect from inflammation and protect from the development of dementia. Once dementia sets in switching from running on sugar to running on ketones could also be protective from further decline and potentially allow for the reversal of dementia. Dr. Bredesen wrote an amazing book The End of Alzheimers describing how diet and lifestyle changes can protect from the development of dementia and even to reverse dementia. New research is also emerging examining the role of ketogenic diet in dementia care.

In one study, 20 subjects who already had diagnoses of mild cognitive impairment or Alzheimer’s Disease were given MCT oil (which amplifies ketone production). The results indicated that the MCT oil was helpful for subjects’ cognitive functioning. However, individuals with Alzheimer’s Disease did not show as many benefits. While this dietary approach may be helpful for maintaining cognitive functioning and slowing dementia symptoms, it may not be as helpful for treating advanced Alzheimer’s Disease. Ultimately, the science on KD and dementia is mixed and more research is needed. If you are interested in learning more about how to prevent the development of dementia and to protect your brain I recommend reading The End of Alzheimers and speaking with integrative medicine and psychiatry or functional medicine clinicians.

“Alzheimer's doesn't have to be your brain's destiny, says neuroscientist and author of ‘Still Alice,’ Lisa Genova. She shares the latest science investigating the disease -- and some promising research on what each of us can do to build an Alzheimer's-resistant brain.”