Can a Ketogenic Diet Help A Concussion?
Updated: Dec 13, 2020
You’d be hard-pressed to say that diet does not have a large effect on the health of an individual. To that effect, we can also extend this notion to diet’s effect on brain and nervous system health. One of the trends I’ve noticed in the healthcare industry is the use of a ketogenic diet (KD) as an intervention in neurologic conditions. However, this is somewhat old news as a high-fat ketogenic diet has been used since the 1920s for those with epilepsy with very positive results.
One of my passions is helping veterans. I believe they and their families have sacrificed so much to serve our country and I believe it is part of my career’s calling to help them with their medical issues when they return home. A major debilitating condition that many veterans face are traumatic brain injuries sustained during duty.
Unfortunately, many of these veterans, and civilians for that matter, deal with the long-lasting complications following their TBI without much help.
With that said, there is a great need to search for possible interventions for those suffering from this condition. Over the last month, I have read over 60 peer-reviewed papers examining the evidence of whether a ketogenic diet is an effective interventional tool for those with TBIs. Here is a rough outline of my findings.
Getting hit in the head is just the beginning to a long downward spiral
A lot of things go wrong with a TBI. Although, not many “problems” show up on conventional imaging (MRI, CT scans), newer technology such as diffuse tensor imaging and animal studies have revealed what’s known as “secondary injury”. This term encompasses the cellular dysfunction that results from a blow to the head. Conservative estimates say this secondary injury can last a few weeks to months. However, other research suggests this may last up to years especially for those who sustain multiple TBIs back-to-back.
After a TBI, neurons and the surrounding supporting cells (e.g. microglia, astrocytes) try their best to maintain homeostasis but sometimes things get out of hand.
We see a lot of ion (potassium, sodium, calcium) shifting in and out of the cell which can lead to cerebral edema (fluid in the brain). With this ion shift, you also get a cascade that leads to cell and neuron death. Neurons get excited and there is an imbalance in neurotransmitters, namely glutamate and GABA. The blood-brain barrier which usually serves to allow only certain molecules from the blood into the brain (and vice-versa) increases in its permeability. This means peripheral inflammation elsewhere in the body (joints, gut, etc) can now get into the brain and cause neuroinflammation and possibly brain autoimmunity. Finally, the energy-producing parts of the cell called mitochondria become deranged as they attempt to correct for some of these imbalances. As a result, less ATP gets produced by the cell to maintain basic cellular functions.
One of the most striking things about a TBI is the shift we see in how and what the nervous system cells use for their energy source. In the first few days following a TBI, the nervous system uses a lot more glucose (blood sugar) in a process called “glycolysis”. However, this is followed by a much longer suppression of glycolysis. I have included a graphic depiction of this phenomenon below.
Many researchers have speculated that this observation may mean that glucose may not be the best fuel source for injured brain during this time.
Introducing the ketogenic diet
This is where the ketogenic diet comes into play. This is a high-fat, low-carbohydrate diet (usually less than 10% of total calories or 50 g of carbohydrates) that results in the production of ketone bodies by the liver. A typical day of food for a 200-pound male doing a KD looks like this:
· 8 oz chicken thighs
· 8 oz chicken breast
· 6 large eggs
· 4-6 servings of vegetables
· 1.5 avocados
· 3 tablespoons coconut oil
· 3 tablespoons olive oil
· 1 tablespoon butter
You’ll notice here, that there are no denser carbohydrates such as potatoes, fruit, rice, quinoa. However, an individual may be able to get away with some carbs (e.g. a piece of fruit) around their workouts if it entails more than walking or jogging on the treadmill.
Animal vs human research
Through my research of this topic, I have come to appreciate the nuances of the possible therapeutic effect of a KD for those with a TBI. I’d like to present my findings here soon but first would first like to share the source of these findings. A majority of this research is performed in animal models (rats and mice mostly). However, we can glean some information from prior research using a KD for other neurodegenerative conditions. Specifically, seizures/epilepsy acts as a great model for understanding TBIs as they share much of the same pathophysiology (how and what goes wrong in the disease). Using seizures and animal data, we can come away with some potential mechanisms of how a KD and the resulting ketone bodies can impact an injured brain.
Unfortunately, we only have one human clinical trial examining a ketogenic diet for those with TBIs. However, this was a poorly designed study, only having 20 patients in the trial and treated for 5 days with intravenous nutrition, so we can’t say much about this. Animal studies have revealed much more interesting findings. I believe a KD and ketone bodies have 3 major pathways by which they may serve as beneficial for a concussed brain.
Ketogenic diet and the immune system
The first is that the immune cells of the brain (microglia) express receptors and are sensitive to ketones. Binding of ketones to microglia suppress their function. This may be of benefit as a heightened activity of these immune cells directly increases brain destruction after the acute period following a TBI.
Ketogenic diet and oxidative stress
The next is that a KD may impact oxidative stress in the nervous system. After a TBI, oxidative stress through the production of free radicals such as hydrogen peroxide and superoxide roam around the brain and cause more destruction to tissue. Through rat studies, we see that a KD may alleviate some of this oxidative load by producing more of the enzymes responsible for the degradation of these oxidative molecules.
In addition, ketones improve mitochondria function and can improve the energy status of the cell. This may possibly serve to give the cell the energy required to return to homeostasis.
Ketogenic diet and neurotransmitters
Finally, a KD may be of benefit by balancing out neurotransmitters in the brain. Of note, a KD can induce a decrease in the excitatory neurotransmitters called glutamate and increase the inhibitory neurotransmitters called GABA. This is speculated to be one of the major beneficial mechanisms by which a KD serves to be helpful for those with epilepsy.
This all sounds exciting doesn’t it? Shouldn’t everyone with a concussion go on a KD? My thoughts on this are two-fold.
The “good” of the KD for those with TBIs is that there is promising mechanistic research. We know that a KD helps those with seizures and seizures are a good model for understanding what goes wrong in a TBI. From other human and animal research, ketones seem to be neuroprotective. Finally, some do well with rules and a KD is riddled with such dietary rules.
Nonetheless, I have reservations about utilizing a KD in practice. Admittedly, I innately have bias on this matter. My confirmation bias is that a ketogenic diet presents a practical dilemma for many individuals surrounded by a plethora of yummy carbohydrate choices. I see the long-term sustainability of this diet hard to achieve but certainly possible given the right environment and a supporting community.
This research has not been translated to humans. There may be subtle differences in the pathology of TBIs from person to person and a KD may only serve to be beneficial for a subset of these patients. It’s important to understand that this is only a piece of the puzzle and there may be other limiting factors in a patient case that may be higher yield to solve first. As I said before, the practicality of a KD is challenging for most. While some may do well with the restriction laid upon them by the diet, others may not do so well given their current hedonic environment. As another admission of bias, I tried a KD for about a week before going crazy of not being able to have fruit or potatoes. Nonetheless, I know there are great communities out there of those giving this whole keto thing a shot and this may be a great tool for someone who wants to give it a try.
So, what would I do if someone came to me who was dealing with symptoms after a TBI 3 years ago. I think this is where the “N = 1” experiment becomes paramount; meaning, it’s vital to identify what the limiting factors are in their case and addressing those accordingly. Maybe they have a chronic infection or perhaps are dealing with post-traumatic stress after a tour oversees that needs to be dealt with first. If I did use a KD for a TBI patient, I see promise for it within the first month, when the energy fuel-source is shifted. However, I’m not sure if the beneficial effects of a KD seen in animal models in the acute phase translates to beneficial effects in the chronic phase of the disease. The cons of this approach (super restrictive diet) may outweigh the possible positive effects.
How to cheat the system- using exogenous ketones
Nevertheless, I may utilize exogenous ketones to “cheat” the system. By taking pre-formed ketones, we may be able to bypass the restrictions of the KD while still getting some of the neuroprotective properties of a KD.
More recently, Wood and colleagues wrote a nice review showing that taking exogenous ketones may be helpful in those with concussions. While their focus was mainly on newborns, many of the main benefits still apply to adults. You can get these ketone salts as a supplement that will increase ketone body levels in the brain. I believe that using these ketone salts may serve as a practical additional therapy alongside a low-carb and nutrient-dense diet. If someone wanted to put in the work to do a ketogenic diet, taking additional ketone salts may further the benefit from the diet.
In summary, a ketogenic diet has promise and should be considered as part of a comprehensive treatment strategy for those with concussions and other neurological conditions.
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