Could the Keto Diet help with Alzheimer’s? Nutritionist Ed Blonz takes a closer look at the science behind ketogenic eating, brain health and dementia prevention.
Numerous studies, Healthline, AARP… Look around and you’ll find a flood of articles probing the possibility that the popular Keto Diet has brain health benefits — and even, possibly, the ability to help address Alzheimer’s and related dementias. The supposition is based in science: Some research indicates that Alzheimer’s may stem from trouble processing glucose, which is typically the brain’s preferred source of fuel. It is known that as we age, less glucose is able to cross the blood-brain barrier in order to fuel the brain. Researchers and brain health diet experts, like nutritionist Ed Blonz, know that ketogentic plays a role in that dynamic — and it could bring potential problems.
Addressing Alzheimer’s with a diet is tricky — firstly because the cause of the disease is still unknown, and secondly, because studying the link between diet and the disease’s symptoms or progression is a tall order. Like so much with Alzheimer’s, while we know certain foods are better for the brain than others, nothing is definitively proven about the relationship between what we eat and neurodegenerative disease.
All this considered, we wanted to take a closer look at the science behind this popular idea of taking up the keto diet for brain health or dementia prevention, so we sat down with Ed Blonz, Ph.D., a nutritionist and assistant clinical professor at the University of California, San Francisco who studies nutrition and brain health. Here are some of the takeaways from our 2018 conversation.
What is the Keto Diet?
You’ve maybe heard of the keto diet — a diet named for the fatty acid molecules in our bodies that fuel metabolism and support muscle function. It’s high in fats, low in carbs and moderate in protein. A ketogenic breakfast, for example, might involve mixing your coffee with coconut oil, heavy cream and butter, and scrambling eggs with cream cheese, with a side of smoked salmon for protein. All these fats force your body to make and rely on the ketones that the body makes when you aren’t taking in enough carbohydrates. Ketones come from the breakdown of fat when there are not enough carbohydrates to keep the blood glucose within normal limits.
What about the Keto Diet for Alzheimer’s?
While the keto diet can indeed provide a non-glucose source of energy for the brain, and ketones may have potential to affect the pathogenesis of Alzheimer’s disease, there are metabolic costs and nutrient sacrifices associated with this method. In other words, sticking to a ketogenic diet might provide your body with a needed alternate source of energy, but doing so could deprive the body and brain of many other essential nutrients that play a role in your overall vascular health—a key issue associated with the overall risk of Alzheimer’s disease.
The body treats ketones as a limited asset with associated risks. There are enzyme systems designed to prevent the blood level of ketones from getting too high. This can be a problem on a ketogenic diet, because the body cranks out a lot of ketones.
Ketones affect the pH (the acid-base balance) of the blood. We normally have a higher (less acid) pH, but ketones are acidic, and if present at elevated levels, they can lower blood pH, which can seriously mess with our metabolism. The condition called ketoacidosis, which occurs in out-of-control diabetes, can also occur in a poorly composed and monitored ketogenic diet, and this can be serious—even fatal.
On a biochemical level, using ketones as a source of energy for the brain does make some sense. In fact, the body relies on this alternative source of fuel when there is not food available—likely an evolutionary advantage for when the food supply is less stable.
However, a person does not need to adopt a ketogenic diet to produce ketones. In addition to messing with the body’s acid-base balance, carbohydrates get cut out of a keto diet, or down to a minimum, and this pushes many healthful foods–fruits and healthy grains—off the plate.
What the keto diet does for your heart
One of the accepted tenets in the battle against Alzheimer’s is that we need to focus on the health of the heart and vascular system to help prevent Alzheimer’s, or at least slow its progression. You’ve probably heard it before, but it’s true: What is good for the heart is good for the brain.
This what the MIND diet — a diet high in fruits and vegetables, fish and poultry, and olive oil — is all about. Preliminary studies have shown that adhering to the Mediterranean-based, heart- and brain-healthy diet may lower the risk of Alzheimer’s by as much as 53%.
If you opt, instead, for a ketogenic diet to provide ketones, you are thwarting the healthful eating element of the equation and missing out on a lot of nutrients. Relying on a ketogenic diet might provide some short-term benefits, but it would likely mess things up in the long run.
Using diet to lower your Alzheimer’s risk
With this as prologue, you can see why a ketogenic diet should not be the first approach to maintaining brain health.
According to Blonz, the primary focus must be to maintain vascular health by eating a healthy diet and exercising, doing everything in your power to reduce the incidence of health conditions associated with an increased risk of Alzheimer’s disease.
These are referred to as “co-morbidities,” include diabetes, insulin resistance, heart disease, obesity, and hypertension.
A high-fiber diet for brain health
A different approach, Blonz suggestions, could be to take a supplement of ketones (like beta-hydroxy butyrate) or fats that the body metabolizes into ketones. Caprilic acid, an eight-carbon fatty acid that makes up eight percent of the fats of coconut oil, is a fat that gets metabolized into a ketone after absorption. Another important piece of this approach is maintaining a high-fiber diet. Aside from being a boon to general health, fiber is often fermented in our gut into a type of fatty acid that gets turned into a ketone after absorption.
UPDATE: 00:01, February 3, 2023 — This article from April 2018 has been updated with new information to help our readers.