By now you’ve probably heard the buzz about the ketogenic diet – a low-carb, high-fat diet that supports weight loss and diabetes management. You may have also heard that it can boost cardiovascular health, treat epilepsy and headachesand  increase the effectiveness of chemotherapy and radiation for patients undergoing cancer treatments. But, did you know that the ketogenic diet may also protect against cognitive decline, such as in Alzheimer’s Disease?

Alzheimer’s Disease is a neurodegenerative disease and the most common cause of dementia. It is estimated to affect approximately 50 million people worldwide, and the prevalence continues to increase. This devastating disorder causes changes in the brain that impair memory, cause difficulty in thinking and can impact a person’s ability to take care of themselves. So, you are probably wondering, how can a simple change in diet potentially protect from these dramatic changes in the brain?

Well, first, let’s learn a little more about the ketogenic diet and how it works. The ketogenic diet consists of eating limited carbohydrates, the typical source of energy for our cells, and replacing the carbohydrates with a high consumption of healthy fats. This encourages the body to enter a state of ketosis, where when deprived of its usual energy source (carbs), the body breaks down fat to produce ketones (or ketone bodies).  So,  the ketogenic diet trains the body to break down fat by depriving it of carbohydrates, thereby providing an alternative source of energy (ketones).

Okay, now let’s discuss how this all plays into Alzheimer’s Disease. Studies have suggested a few different ways in which the ketogenic diet may prevent or ameliorate the damaging effects that occur in Alzheimer’s Disease:

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A ketogenic diet may reduce the accumulation of damaging proteins in the brain, lower inflammation, reduce damage to brain cells, and help meet the brain’s energy needs.  In turn, these may result in improved memory and cognition.

The ketogenic diet may reduce harmful protein clusters and tangles in the brain

Alzheimer’s Disease is characterized by accumulation of protein clusters and tangles in the brain that interfere with how neurons communicate with each other. This can also activate the immune system and cause brain inflammation. Studies in animal models of Alzheimer’s Disease illustrate that a ketogenic diet reduces these clusters and tangles in the brain and importantly, improves cognition. Protein clusters and tangles start accumulating years before brain function declines. A ketogenic diet might reduce their accumulation and their harmful effects. 

The ketogenic diet may decrease inflammation in the brain

Inflammation has been implicated as a major mechanism of neuronal damage during aging and Alzheimer’s, resulting in neuronal loss in the areas of the brain responsible for memory and cognitive processes. The ketogenic diet has been shown to reduce production and activity of pro-inflammatory cytokines, thus reducing inflammation. Additionally, the ketogenic diet has been reported to counteract brain inflammation through microglia, the immune cells of the brain. 

The ketogenic diet may slow down damage to brain cells

Reactive oxidant species (ROS) are compounds our cells produce normally. They have important functions in the body but if they’re not promptly removed they can damage your cells. Your cells defend themselves against ROS by making antioxidants, but if there are more ROS than your cells can deal with, they enter a state known as oxidative stress.  Oxidative stress damages neurons during aging and during Alzheimer’s Disease. It’s been shown that ketone bodies can decrease ROS and thus decrease  oxidative stress. Additionally, the ketogenic diet may also induce antioxidants, which can also decrease levels of ROS and protect neurons. 

The ketogenic diet may prevent the energy deficit that occurs during aging 

There is growing evidence that the brain is increasingly unable to use glucose as it ages and this also plays a central role in Alzheimer’s Disease. A ketogenic diet may be beneficial in this sense as it supplies ketones as an alternative source of energy for the brain. Some studies have suggested that ketones are even a more efficient source of energy compared to glucose! Though much of the information about how the ketogenic diet has been drawn from laboratory studies in cells and animals, clinical studies have also reported promising results. A recent clinical trial reported that patients with Alzheimer’s Disease who completed a 12-week modified ketogenic diet displayed improvements in daily function and quality of life, which are two factors that can be dramatically altered in people living with dementia.

Larger and longer studies are needed to confirm these benefits, but the ketogenic diet could prove to be a gamechanger in the treatment of Alzheimer’s Disease as well as other neurodegenerative disorders!