Alzheimer’s and The Ketogenic Diet: A Delicate Relationship

Alzheimer’s and The Ketogenic Diet: A Delicate Relationship

There are so many things to be appreciated about the ketogenic diet, and one of them is its effect on the brain. It’s estimated that more and more people are living with Alzheimer’s and that in 2030, about 66 million people worldwide will have the disease [1]. In today’s article, we’re going to explore the connection between following a diet which is ketogenic and Alzheimer’s.

Can the keto diet prevent further mental decline? How does it work? What must you consider when using keto to fuel the brain? I know you’re eager to learn more, so let’s dive in.

What Is Alzheimer's Disease?

Let’s begin by defining what Alzheimer’s disease is. Alzheimer’s disease is a progressive and irreversible brain disorder, and it’s the most common cause of dementia. It affects your thinking, memory, and behavior. People with Alzheimer’s find it difficult to perform very simple tasks and execute decisions.

According to experts, up to 5.5 million Americans have Alzheimer’s disease. It is most commonly found in the over 65 age bracket, with only 5% of sufferers experiencing early onset Alzheimer’s. It’s also the 6th leading cause of death in the US [2].

So how did the disease get its name? “Alzheimer’s disease” was named after Dr. Alois Alzheimer, a German physician in 1906 who met a 51-year old woman with a rare brain disorder. During autopsy, the woman’s brain showed abnormal tangles and plaques that became characteristic of the disease.

What Causes Alzheimer’s?

Scientists suggest that a combination of factors lead to Alzheimer’s. These include genetic, lifestyle, and environmental factors. A study revealed that people who had the apoE (apolipoprotein E) gene were at a higher risk of developing late-onset Alzheimer’s [3].

Perhaps you’ve heard some medical professionals refer to Alzheimer’s as “unofficial type 3 diabetes.” This is because scientists are able to observe abnormalities in glucose metabolism in the brains of Alzheimer's patients. PET scan studies demonstrate lowered rates of glucose metabolism (glycolysis) and increased brain glucose levels in Alzheimer’s [4].

In this connection, ketosis may offer protective benefits for the brain since ketone bodies serve as an alternative source of energy.


Signs & Symptoms of Alzheimer’s

For people with late-onset Alzheimer’s, signs and symptoms start to appear in their mid-60s. Those with early-onset Alzheimer’s present signs and symptoms before 65, sometimes beginning in their 30s. What’s interesting is that the disease develops before a person and those around him notice anything unusual.

These signs and symptoms are classified as mild, moderate, and severe depending on the progression of the disease [5]:


In the mild stage, a person with Alzheimer’s experiences subtle changes in their ability to think and remember things. Signs and symptoms include difficulty recalling recently learned information, short attention span, misplacing belongings, getting lost/wandering, and difficulty expressing ideas.


A person becomes more confused and because of this, they may need assistance from loved ones. Signs and symptoms include difficulty recognizing family and friends, delusions and hallucinations, repetitive movements and statements, problems with reading and writing, and confusion with the time and surroundings.


In this stage, a person now becomes totally dependent on their significant others. Signs and symptoms are severe. These include the loss of interest in food, deterioration in language, seizures, difficulty swallowing, increasing infections (skin, respiratory, urinary tract), and the need for complete assistance with eating, dressing, and other activities of daily living.

Can the Ketogenic Diet Treat and Prevent Alzheimer’s?

More research is needed when it comes to the keto diet reversing or preventing Alzheimer’s disease. However, there are a number of studies showing that increased ketone bodies, through the diet, protect the brain by boosting ATP production.

In one study, oral MCT (medium chain triglycerides) increased the level of ketones in subjects with mild to moderate Alzheimer’s disease. Results showed that higher ketone levels were associated with better cognitive functioning and memory [6].

How Can Ketogenic Diet Help in Alzheimer’s?

There is a connection between problems with brain glucose metabolism and Alzheimer’s disease. It is believed that decreased glucose uptake in the brains of AD patients reduces brain function.

Recall that the brain relies on glucose as its sole fuel source except during periods of starvation. This is where we appreciate the keto diet as a promising approach for managing Alzheimer’s [7].

The brain uses ketones as its alternative energy source.

In the absence of glucose, the brain taps into ketones as its backup fuel. Ketones address brain glucose hypometabolism by providing more energy. One of the ketone bodies produced in ketosis, beta-hydroxybutyrate (BHB), happens to be a more efficient fuel source than glucose [8].

To boost your ketones on the keto diet, you must drastically reduce your carbohydrate intake and eat more fat. You may also take MCT oil, exogenous ketone supplements, and do intermittent fasting.


Essential fatty acids play a role in brain function.

One study suggested that the keto diet can ameliorate Alzheimer’s by providing greater amounts of essential fatty acids than a carbohydrate-rich diet [9].

Another study showed that long-chain omega-3 fatty acids reduce the risk of dementia and mental decline. Foods that are rich in omega-3 include fatty fish such as tuna, salmon, and mackerel [10].

Things to Consider Before Starting a Ketogenic Diet in People with Alzheimer’s

1. Quality of foods

When following a ketogenic diet, food quality matters. It’s not just about meeting your keto macros; it’s also about making sure to avoid processed foods and prioritize whole foods.

Because unfortunately, refined and processed foods contain added sugars and compounds that affect cognitive function and mood and eventually lead to other health problems. We want to avoid worsening the condition of an Alzheimer’s patient by steering clear of anything that’s unhealthy.

2. Stage of the disease

During the late stage of Alzheimer’s, a person will lose interest in food and have difficulty in swallowing. Make keto meals more palatable by cooking them with herbs and spices. For example, when making buffalo chicken casserole, be sure to add garlic, onion, and salt and pepper.

Also, provide soft or pureed foods for someone who has swallowing problems. Puree food molds will improve the appearance of pureed meals to make them look appetizing.

3. Preventing constipation

Constipation is one of the side effects when starting a keto diet for the first time. Unfortunately, constipation is a frequent problem in people with Alzheimer’s. To promote bowel movement, serve keto-friendly foods that are rich in fiber such as broccoli, chia seeds, avocado, and leafy greens. Don’t forget to increase water intake.

Ketogenic Food List for Alzheimer’s

A keto diet should limit carbohydrates to 20-50 grams per day. Remember that this needs to be titrated against a person’s activity level. Those with late stage Alzheimer’s may not be mobile at all meaning they will have a lower requirement. At the same time, one should increase healthy fat in the diet to stimulate ketosis. Here’s a list of keto-friendly whole foods that boost brain function:

  • Avocado - Avocados are naturally low in sugar and high in omega-3 fatty acids.
  • Grass-fed meats - Grass-fed beef and pork don’t just taste better, but they’re also free from antibiotics and added hormones.
  • Extra virgin olive oil - This contains polyphenols, antioxidants that are known to protect brain cells against injury. It improves memory and learning [11].
  • Fish and shellfish - Choose salmon, sardines, mackerel, shrimp, and mussels.
  • Eggs - Nutrients in eggs that are linked to brain health include choline, vitamins B6 and B12, and folic acid.
  • Nuts and seeds - These are plant-based foods rich in omega-3 fatty acids. Examples are pecans, macadamias, walnuts, almonds, chia seeds, and flax seeds.
  • Above ground vegetables - These vegetables are lower in carbs. Examples are spinach, lettuce, cabbage, asparagus, broccoli, cauliflower, and kale.

Foods to Avoid in People with Alzheimer’s

Here’s a list of foods to steer clear of on keto. They slow down ketosis, spike a person’s blood glucose and decrease cognitive function because of their sugar content and other harmful ingredients:

  • Refined oils - Not all oils are created equal. The following oils have undergone intense processing and should be avoided: canola oil, corn oil, vegetable oil, safflower oil, and soybean oil.
  • Commercially-baked products - Cookies, cakes, and donuts contain trans fats that increase inflammation in the brain.
  • Sugars - Watch out for sugar pseudonyms in food labels: corn syrup, maple syrup, dextrose, dextrin, cane sugar, and rice syrup.
  • Condiments - Teriyaki sauce, ketchup, mayonnaise, mustard, and any fat-free dressing can pack a lot of sugar (unless you made them yourself).


While more studies are needed to determine whether keto prevents or reverses Alzheimer’s disease, the diet provides ketones that positively affect brain health.

Ketones serve as a backup fuel for the brain, addressing the reduction in glucose metabolism present in Alzheimer’s. Studies show that ketone bodies, specifically BHB, are more efficient than glucose. Therefore, switching from being a sugar burner to fat burner through the ketogenic diet benefits people with Alzheimer’s.

Please don’t disregard professional medical advice when considering keto for Alzheimer’s disease.


  • Alzheimer’s is a neurodegenerative disease. It’s progressive and irreversible, and is the most common type of dementia.
  • Various factors influence the development of Alzheimer’s. These can be genetic, lifestyle-related, and environmental in nature.
  • Signs and symptoms of the disease can range from mild to severe.
  • Research studies show that ketones protect the brain and improve cognitive functioning.
  • Starting the keto diet in people with Alzheimer’s requires a few considerations -- food quality, stage of the disease, and constipation as a keto-adaptation side effect.
  • Prioritize low-carb, high-fat foods that are whole and unprocessed.


  1. Heerema E. Statistics on Alzheimer's Disease: Who Gets It? 2018 September 3 -
  2. National Institute on Aging. What Is Alzheimer's Disease? Content reviewed 2017 May 16 -
  3. Kim J, Basak JM, Holtzman DM. The Role of Apolipoprotein E in Alzheimer’s Disease. 2009 August 13 -
  4. National Institutes of Health. Higher brain glucose levels may mean more severe Alzheimer’s. 2017 November 6 -
  5. National Institute on Aging. What Are the Signs of Alzheimer's Disease? Content reviewed 2017 May 16 -
  6. Włodarek D. Role of Ketogenic Diets in Neurodegenerative Diseases (Alzheimer’s Disease and Parkinson’s Disease). 2019 January 15 -
  7. Henderson ST. Ketone bodies as a therapeutic for Alzheimer's disease. 2008 July -
  8. Fan S. The fat-fueled brain: unnatural or advantageous? 2013 October 1 -
  9. Gasior M, Rogawski MA, Hartman AL. Neuroprotective and disease-modifying effects of the ketogenic diet. 2006 September -
  10. Cole GM, Ma QL, Frautschy SA. Omega-3 fatty acids and dementia. 2009 June 12 -
  11. Farr SA et al. Extra virgin olive oil improves learning and memory in SAMP8 mice. 2012 -

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