The Ketogenic Diet and Alzheimer’s Disease

A Ketogenic Meal, Low in Carbohydrates

There has been a lot of hype around the ketogenic diet for weight loss and for improving health. Yet the latest research does suggest some significant potential for treating a number of challenging medical conditions. While data is preliminary, from what we know so far, the ketogenic diet may have a place in the prevention and treatment of Alzheimer’s dementia. 

What Is the Ketogenic Diet?

The ketogenic diet is a diet that eliminates most carbohydrates, replacing them primarily with fat. In essence, the ketogenic diet eliminates grains, beans, sugar, starch and fruit. These carbohydrate-rich foods are replaced with meat and other high-fat foods, including avocados, nuts, oils, cheese and cream. 

The diet is quite strict, but when followed properly, it induces a state called ketosis. Ketosis is when your cells no longer have access to enough sugar for energy production and switch to using fat instead. Running on fat is a cleaner source of energy production, decreasing inflammation and free radical damage throughout the brain and body. 

Since the 1920s, the ketogenic diet has been utilized to treat medication-resistant seizures. Estimates suggest that just over one in ten patients become seizure free on the ketogenic diet with over half of patients reducing their seizures by 50% or more (Neves 2021). 

The Ketogenic Diet and Alzheimer’s Disease: Mechanisms

Alzheimer’s disease is a devastating illness, destroying lives and costing billions of dollars for care and management. Additional, effective treatments are desperately needed. As of late, data has been accumulating that suggests the ketogenic diet may be a valid treatment option for dementia. 

Alzheimer’s disease has been described as diabetes type 3. The condition has clear roots in problems with brain cells utilizing sugar for energy (Kandimalla 2017). The ketogenic diet, by using fat for energy production, effectively bypasses problems with the utilization of sugar. 

Beyond problems with energy metabolism, Alzheimer’s disease is characterized by two types of damage: amyloid plaques and tau tangles. A ketogenic diet, in animal models, has been shown to reduce amyloid plaques and decrease their toxicity (Broom 2019).  Additional evidence suggests potential reductions in tau tangles as well (Kashiwaya 2013). However, it is worth noting that not all animal studies have found clear benefits on tangles and plaques (Brownlow 2013). 

As previously mentioned, the ketogenic diet also has inflammation-reducing effects that are likely relevant for treating and preventing dementia. Studies have found that ketosis increases the production of anti-inflammatory compounds while reducing the inflammation associated with energy production (Davis 2021). This reduces overall inflammation throughout the body and brain, reducing damage that can lead to dementia.

The Ketogenic Diet and Alzheimer’s Disease: Human Studies

There are two main approaches to instituting ketosis as a treatment for Alzheimer’s disease: ketogenic supplements that supply medium-chain triglycerides or a full ketogenic diet. Studies with ketogenic supplements have been somewhat mixed. 

Ketogenic Supplements: Medium-Chain Triglycerides

Coconut Is a Source of Medium-Chain Triglycerides

The largest trial on ketogenic supplements included over 400 Alzheimer’s patients treated with 20 grams of medium-chain triglycerides per day. Medium-chain triglycerides are a type of fat that is burned preferentially in the body for energy. After six months, there were no detectable changes in cognition (Henderson 2020). 

However, a separate study of over 100 patients with mild cognitive impairments, a precursor to dementia, found improvements with a ketogenic supplement. In the study, 30 grams of medium chain triglycerides improved memory, language skills and cognition over six months (Fortier 2021).

The majority of the remaining studies also found benefits for cognition or other parameters by supplementing medium chain triglycerides (Lilamand 2022). Overall, the data suggests that ketogenic supplements may be helpful for improving brain function, especially in earlier stages of the disease, but more research is clearly needed. 

The Ketogenic Diet

Studies on the ketogenic diet and dementia are small and of short duration. While more data is needed, the preliminary data suggests promise. 

The first published study was just in 2019. They used a modified Mediterranean ketogenic diet with under 20 grams of carbohydrates per day. Participants were older with mild cognitive impairment or no signs of dementia. The diet lasted only six weeks. However, they found improvements in gut flora. In addition, markers of dementia plaques and tangles in patients on the ketogenic diet were also reduced (Nagpal 2019). 

The second study also utilized a modified Mediterranean ketogenic diet in patients who were prediabetic with memory complaints or mild cognitive impairment. The six-week pilot study also found similar results, with decreased markers for plaques and tangles in the spinal fluid of patients (Neth 2019). 

The final published study was longer, lasting three months. It also used a modified ketogenic diet and study subjects all had diagnosed Alzheimer’s disease. During the study, cognitive function increased, but the results weren’t significant, likely since it was still a small, short study. However, daily function and quality of life improved significantly (Phillips 2021). Both of these factors are of key importance when caring for dementia patients. 


While the data is quite preliminary, it does appear that a ketogenic diet may have a place in the treatment of Alzheimer’s disease. Considering the devastating effects of dementia, additional tools or treatments are desperately needed. As it stands, there are no standard treatments that effectively slow or reverse the condition. Current treatments only help mitigate symptoms. And while the ketogenic diet is not easy to follow, it could still be a welcome addition for dementia prevention and treatment.  

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