Ketogenic Diet. Alzheimer’s. Insulin Resistance. Brain Function. Although seemingly unrelated on the surface, these terms are intricately connected. Current research highlights how the ketogenic diet may favorably affect cognitive function by improving glucose homeostasis.

What Is the Connection Between Diabetes and Cognitive Function?

Neurons in the brain have one of the highest energy demands in the body and require quick and continuous glucose supply for all neuronal functions.^1,2 As neuronal function is tightly linked to glucose supply, conditions that alter or negatively impact glucose metabolism can directly affect cognitive function.²

For instance, Alzheimer’s disease is a type of dementia that researchers are increasingly recognizing to be related to insulin resistance.³ Studies have shown that type 2 diabetes mellitus (T2DM) is associated with an increased risk of dementia and Alzheimer’s disease and that insulin resistance plays a significant role in cognitive decline.⁴ Insulin and insulin signaling affect a wide array of neural functions including glucose homeostasis in the brain, regulation of neurotransmitters, neuronal and synaptic integrity, and cognition.³ In addition, researchers are discovering that insulin plays an important role in clearing beta-amyloid plaques and tau protein, key contributors to cognitive decline in Alzheimer’s disease.⁵ Given the evidence, the development of insulin resistance, hyperglycemia, and ineffective glucose uptake by the brain seems to affect various neural functioning and contribute to cognitive decline.

Does Ketogenic Diet Improve Cognitive Function? 

How might the ketogenic diet then play a role in improving cognitive function? The ketogenic diet has recently gained popularity as a very-low-carbohydrate and high-fat diet that promotes weight loss.^6,7 However, studies are showing that its benefits may extend beyond improving weight.

Current research is finding that the diet may have benefits on mental and cognitive health as well as metabolic health.^7,8 A 2023 systematic review on the effects of the ketogenic diet on cognition reported that majority of human studies it reviewed found that the diet has favorable effects on working memory, reference memory, and attention.⁹ In addition, a recent mice study discovered that the ketogenic diet in a mouse model with Alzheimer’s disease improved synaptic function, showcasing the diet’s potential in benefiting cognitive abilities. Despite ongoing research, the exact mechanisms behind how the ketogenic diet might improve cognitive function are yet to be elucidated. However, given the tight link shown between cognitive diseases and insulin resistance, one potential mechanism may be through the ketogenic diet’s beneficial effects on improving metabolic parameters, including insulin resistance.^10–13

Should You Be on the Ketogenic Diet? 

If you have diabetes and are concerned about your mental and cognitive health, it is important to make changes to your lifestyle by eating a healthy diet and exercising regularly to achieve and maintain glycemic targets.⁵ Make sure to check with your health care team that the ketogenic diet is safe for you. If you and your health care team have decided to follow the ketogenic diet to improve both metabolic and cognitive health, there are several different types of the ketogenic diet you can choose from. To start on the most common form of the ketogenic diet, the standard ketogenic diet, you can begin by counting your macronutrients, making sure to consume 70% of your calories from fat, 10% from carbohydrates, and 20% from protein. You can use various sources of fat, carbohydrate, and protein to diversity your diet, but sticking to this ratio every day is key. If meal planning with stringent restrictions is difficult, there are ketogenic delivery services available to help you get started. Additionally, avoiding some common mistakes and researching keto-friendly snack ideas can help you be on track.