Intermittent Fasting Treats Alzheimer's Disease ... Maybe

On November 10, 2019, I wrote that I had attended the Tri-Cities Alzheimer's and Dementia Conference, serving as event photographer.  During the Q&A for a talk by a well known neuropsychologist, someone asked whether the keto diet is effective in fighting Alzheimer's disease.  I was surprised by the question, and even more surprised by how the speaker responded.  He said, "It's being studied," and nothing more.  However, the way he said that suggested some optimism that there may be something  in the keto diet worth pursuing.

I was familiar with the keto (for "ketogenic") diet and knew that it piled on fats, while trying to drive the intake of carbohydrates to zero.  The intent is to put the body in a state of ketosis, where the body burns fat rather than stored carbohydrates.  It's a very difficult diet to maintain, but some people have used it effectively to lose weight.  It's also used to treat epilepsy and type 2 diabetes.  

There is reason to believe that if a keto diet emphasizes animal fats and proteins it can have adverse, sometimes deadly consequences.  However, it may prolong life span when it emphasizes plant-based fats and proteins.  At least, this is indicated in animal studies.  Most nutritionists seem to consider the keto diet a fad, although it has energetic supporters.  Other authorities openly discourage it.  But I'd never thought of the keto diet in terms of fighting Alzheimer's disease and expected the speaker to simply dismiss the idea.

We were in Hawaii for three weeks during Christmas visiting family there.  One morning, I got an email from my sister asking if I was familiar with research connecting intermittent fasting with controlling Alzheimer's disease.  While I recalled the conference speaker, and I suspected a connection with fasting, I had never investigated the idea.  That same day, at a family gathering, my wife's nephew commented that he was engaged in a program of intermittent fasting, and he had clearly lost weight.  There is a relationship between the keto diet and intermittent fasting, in that both intend to move the body into a state of ketosis.

What is intermittent fasting?  Basically, it consists of several possible rhythms of fasting and normal eating.  These might be a fast of 16 hours from, say, 7 p.m. to 11 a.m. the next day or limiting caloric intake for 500 calories in a day, two days a week.  (You would eat normally the other five days.)  And there are other variations.  Any of these should induce periods of ketosis.  In Beating the Dementia Monster, we recommend a daily 12 hour fast, mainly to address the possibility of type 2 diabetes.

So why might ketosis be beneficial to someone with Alzheimer's disease?  Dr. Mark Mattson at Johns Hopkins University has led research on this lifestyle modification and speaks strongly in favor of it.  In this TEDx Talk, Dr. Mattson explains what he believes has been found in his and other research.  He explains that when ketosis is induced by intermittent fasting, breakdown of fats produces ketones, such as acetone.  The ketones can serve as an energy source, when glucose from carbohydrates is missing from the blood stream.  The brain, of course, is one of the biggest users of energy in the body.

But what's the connection to Alzheimer's disease?  According to Dr. Mattson, stress during ketosis prompts the generation of our old friend, the brian-derived neurotrophic factor (BDNF).  Yes, that's the same protein that's generated during aerobic exercise.  As we discuss in Beating the Dementia Monster, BDNF attends to neurons damaged by Alzheimer's disease and prompts stem cells in the hippocampus to form new neurons.  Dr. Mattson believes that the combination of intermittent fasting with physical exercises can be a powerful weapon when confronting or preventing Alzheimer's disease.

What do I think?  Well, it sure has a faddish feel to it, and I'm always skeptical of fads.  And adverse health consequences must be considered carefully.  But who knows?  The research continues.  

The popularity of intermittent fasting (ask Google about how popular) will likely shed light on its safety.  

For me, extending my 12 hour fast to 16 or 20 hours is not a huge change, so I'm giving that a shot.

We got back from Hawaii last night.  While there, I took these pictures.