In PART I of this blog post I discuss some of the fundamental mechanisms underlying concussion pathophysiology and I explore the interplay between glucose, insulin release, fat intake, ketosis, and neurologic recovery. In part II, we will discuss how omega-3 fatty acids support general neurologic health and the potential therapeutic role for concussions. I will then attempt to establish some practical takeaways, as I currently see it. In PART III I will provide some sample menus implementing the strategies discussed.
Again…the purpose of my blog posts are to facilitate thought and discussion or perhaps even motivate research to answer the remaining questions on this topic. That is all. If you think that you have a concussion, GO SEE A DOCTOR!!!
Omega-3 fatty acids:
Omega-3 fatty acids are long chain polyunsaturated fatty acids and include α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Over 97% of the omega-3 fatty acids present in the human brain is DHA which plays a vital role in maintaining membrane fluidity, receptor activity, and signal transduction [1, 2]. In the developing human brain, DHA accumulates in hippocampus and frontal cortex, regions that are important for executive functioning, learning, and memory [2-4]. Foods that are highest in DHA concentration include fatty cold water fish such as salmon, trout, sardines, mackerel, and herring. There are also high amounts of DHA in human breast milk, again highlighting its importance in brain development.
I has been demonstrated that increased omega-3 fatty acid consumption (via seafood or DHA supplementation) is associated with increased brain volume and improved cognition [5-9]. A decreased risk for developing Alzheimer’s is also associated with increased intake [10-13].
Total DHA concentrations in the brain decrease after a mild traumatic brain injury (TBI), which may indicate an increased therapeutic potential in this context . Rats given a diet higher in omega-3 fatty acids were found to have significantly reduced oxidative damage, improved markers for neuroplasticity, better cognitive performance, reduced glutamate excitotoxicity, and less structural damage following a TBI [2, 14-20]. Supplementing isolated DHA was also associated with better cognitive performance, significantly improved biomarkers for metabolism and reduced oxidative stress and damage secondary to a TBI [21-25]. DHA supplementation has also been found to reduce inflammatory markers following brain trauma [26-28].
What about omega-3 fatty acids for concussion in humans?
I could not locate a human study examining omega-3 fatty acids specifically for concussions. There are, however, two ongoing double-blinded, placebo-controlled trials looking at DHA for sport-related concussions in both adolescent and college athletes [29, 30] (links to studies below).
What do we know?
- One of the primary components underlying concussion pathophysiology is the dysfunctional metabolism of glucose.
- Human brains are able to utilize other energy substrates, particularly ketones, to generate ATP, especially during metabolically challenging situations.
- Ketone synthesis is directly influenced by insulin levels. If you reduce insulin enough, you eventually dial up ketogenesis.
- This ketogenic pathway is already utilized for pediatric seizure disorders and the vehicle used is a ketogenic diet, or some variation.
- Negative neurologic effects are observed with a diet that is high in refined carbohydrates. This is also true in the specific context of a TBI. This has not been evaluated for human concussions.
- There is a growing body of evidence demonstrating benefits from ketogenic diets for other neurological diseases, including dementia.
- There is a substantial body of evidence demonstrating significant benefits from a ketogenic diet for traumatic brain injuries (severe and mild) in animal models.
- Human studies supporting the use of ketosis for TBI or concussion is lacking, not because of negative results, but because the studies have not yet been done.
- You can achieve ketogenesis easier with medium chain triglyceride supplementation, allowing for a more moderate reduction in carbohydrates.
- Increased DHA consumption appears to provide general neurological benefits to humans, as well as in animal-models of traumatic brain injury.
- Omega-3 fatty acids are being looked at for concussions in two ongoing human studies.
Given the significant therapeutic potential behind these dietary strategies, more research is badly needed to validate what works.
- Does an increase in serum ketone levels improve concussion recovery and/or symptoms in humans? If so, in what ways and by how much?
- If effective, what serum ketone levels are needed for a therapeutic effect?
- If effective, in what population? What age groups?
- Do serum levels need to be higher for older patients compared to the pediatric population for therapeutic benefits?
- How practical is it to implement a classical KD in a typical clinical setting?
- Are there any roles for exogenous ketones? MCT oil supplementation? Incorporating more MCT containing foods into the diet?
- How do supplements come into the picture? DHA? MCT’s? Exogenous ketones?
Where do we go from here…
Peer-reviewed, scientific studies looking directly at ketosis for concussions do not yet exist. As I see it, we have two basic options. We can logically and rationally look at the evidence that does exist. We can critique the mechanisms and evaluate the potential for harm (as you should for ANY intervention). We can evaluate the practicality and cost/time effectiveness of implementing the intervention. And if the answers to these questions remain favorable (which in my opinion they mostly do), we can continue making dietary recommendations for concussions.
It will likely be many years, if ever, before we obtain clear evidence based answers to all of these questions. After examining the literature that IS available, and doing a little cost/benefit analysis, there appears to be adequate evidence and rationale to support some broad dietary recommendations…
- Eat a diet that limits hyperglycemia and insulin spikes (by reducing refined carbs/sugars) **
- Increase consumption of healthy fats
- Eat adequate amounts of food with high DHA content (about 3-4 servings of cold-water fatty fish a week)
- Cooking with, supplementing with, or eating foods that are rich in MCT’s should be considered ***
**A potential downside here would be in implementing abrupt carbohydrate changes in the insulin-dependent diabetic population. There would need to be a lot more physician chaperoning in this more medically challenging situation to avoid severe hypoglycemia.
***A potential downside with MCT oil supplementation is gastrointestinal side effects (speaking from experience). This can be mitigated through a slow gradual incorporation into the diet.
Keep in mind, that the average population are eating breakfasts full of bagels, cereals (with added sugar), toast, jelly, waffles, pop-tarts, donuts and washing it all down with a tall glass of orange juice. The lunches have plenty of French fries, breads, colas, potato chips, and corn snacks. Dinners with a lot of pasta, breads, and always some type of dessert. Athletes are commonly pounding those sugary sports drinks and chowing down on sugar laden protein bars. Don’t forget all of the insulin-spiking snacks consumed in between.
When this is the baseline, eating according to the above listed guidelines has tremendous therapeutic potential.
In PART III I will get more specific by providing some example menus utilizing the strategies discussed. I will also briefly touch on the topic of supplements vs. whole food sources of omega-3 fatty acids (fish oil/DHA) and MCT oil.
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