Are carbohydrates holding us back from our true potential? Exploring the possibilities of a ketogenic diet.

in Article, Pop Culture
October 15th, 2013

It is hard to avoid carbohydrates in the world we live in today. Since the industrial age 100-200 years ago, factories have been able to produce large quantities of sugar and white flour to feed the masses. Really though, foods high in carbohydrates (such as pasta, bread, rice, and potatoes) have only been available to us since the rise of agriculture, approximately 5-10,000 years ago. Prior to that, humans assumed a hunter-gatherer lifestyle where our diets consisted primarily of animal products and low starch vegetables; this was basically whatever we could find in nature without growing ourselves. According to Stephen D Phinney, simply due to circumstance, it is likely that the hunter-gatherer era of humans followed a high fat, moderate-high protein, and very low carbohydrate diet [6]. This has become known as a ketogenic diet, named after ketosis, a natural metabolic state the body undergoes when carbohydrates are nearly eliminated from one’s diet.

A typical ketogenic diet might be proportioned into 70% fat, 25% protein, and 5% carbohydrates. While in ketosis, the body utilizes fatty acids as an alternative source of energy due to the glucose deficit. To accomplish this, acetyl CoA, which is normally oxidized into H₂O and CO₂ as part of the citric acid cycle, is converted by the liver into acetoacetate and 3-hydroxybutyrate, also known as ketone bodies. These ketone bodies are now free to flow where needed and be used as fuel for metabolic processes. It is worthwhile to note that ketone bodies are very effective respiratory fuels; whereas 100 g of glucose generates 8.7 kg of ATP, 100 g of 3-hydroxybutyrate can yield 10.5 kg of ATP, and 100 g of acetoacetate 9.4 kg of ATP. Most areas of the body, such as the brain, will use ketones whenever provided to them (in fact the blood-brain barrier has a very effective transporter for ketone bodies). However, there are still some processes that are partial to glucose for energy metabolism. In these cases, glucose is supplied by hepatic gluconegenesis, where the liver converts non-carbohydrate sources (such as fatty acids and amino acids) into glucose [4].

 

There are several important implications to consider when undergoing a ketogenic diet. For one, the diet’s most famous side effect is fat loss. In fact, ketosis is the underlying principle behind low carbohydrate diets such as the Atkin’s diet. When one’s caloric intake is below what is required for weight maintenance, in a ketogenic state the body will immediately favor the usage of its own fat stores to provide cells with energy. This effect is also widely influenced by  hormone levels, particularly insulin. Insulin spikes happen whenever large amounts of carbohydrates, especially sugars, are consumed. High insulin encourages the body to store consumed carbohydrates as fat in order to prevent blood-sugar levels from rising too high. In the initial stages of ketosis, insulin drops significantly; coupled with a calorie deficiency, this will result in rapid fat loss without loss in muscle tone. As one continues in ketosis however, insulin will compensate and rise to a moderate level to prevent complete fat loss. People who follow a ketogenic diet for the purposes of weight loss often have weekly or biweeky “carb up” days where large amounts of carbohydrates are consumed to modulate insulin. This allows the body to experience the drop in insulin that happens as you first enter ketosis more frequently, resulting in greater fat loss [5].

Weight loss is the most popular use of a ketogenic diet, however it is not the only one. A surprising find is that ketogenic diets have been prescribed to patients of intractable (not easily cured) epilepsy – and is a great success! “According to The Epilepsy Foundation, ketogenic diets have been shown to help two in every three children who try it. Futhermore, seizures have stopped completely in one third of the cases” [2]. Scientists and doctors are currently unsure of the correlation between ketosis and the reduction of seizures. One hypothesis is that the brain prefers ketone bodies as a source of fuel over glucose. An article by Emily Deans M.D. suggests that a ketone metabolism prevents glutamate from producing an overabundance of aspartate (which in high levels is neurotoxic) in favor of GABA, an inhibitory neurotransmitter [1]. Other authors base their findings on the idea that ketones are simply a more efficient fuel than glucose, producing less free radicals in its breakdown and keeping neuron resting potential more stable [3]. These theories are supported by anecdotal experiences with the diet; many who try it often report substantial changes in their cognition, largely in a positive sense. People have reported less lathargy, increased alertness, greater mental clarity and sharpness, quicker thinking, improved mood, increased productivity, and a natural need for less sleep. Biological anthropologists argue that these findings are not surprising considering that the diets of earlier human beings were likely ketogenic and thus our bodies are better adapted for this lifestyle [6].

As a disclaimer, it is important to realize that the long-term effects of being on a ketogenic diet are not yet understood. Some doctors are concerned that a ketogenic diet may place stress on the kidneys, putting one at greater risk of kidney stones due to excess urination of ketone bodies [2][3]. The long term effects of ketosis on the liver, where the biochemical process of ketosis takes place, is also unknown. While many people do experience positive reactions when trying a ketogenic diet, there are others who reportedly feel worse while doing so. This presents a difficulty in establishing an ideal diet for the entire human species. It appears that different people are adapted for different needs, which is also evident when observing the many different morphic body types across the planet. In conclusion, to anyone reading this article, I suggest you do thorough research and consult your health provider before attempting a ketogenic diet to avoid unexpected reactions.

 

~ Emir Turkes

Sources:

[1] Deans, E. (2011, April 18). Your Brain On Ketones. Retrieved October 15, 2013, from https://www.psychologytoday.com/blog/evolutionary-psychiatry/201104/your-brain-ketones

[2] Dy, E. (n.d.). Dieting and Ketosis. Retrieved October 15, 2013, from http://biochemproj.blogspot.com/p/dieting-and-ketosis_08.html

[3] Fan, S. (2013, October 3). Brain, livin’ on ketones – a molecular neuroscience look at the ketogenic diet. Retrieved October 15, 2013, from http://www.neurorexia.com/2013/03/24/brain-livin-on-ketones-a-molecular-neuroscience-look-at-the-ketogenic-diet/

[4] Manninen, A. (2004). Metabolic Effects of the Very-Low-Carbohydrate Diets: Misunderstood “Villains” of Human Metabolism. Journal of the International Society of Sports Nutrition, 1, 7-11. Retrieved October 15, 2013, from http://www.jissn.com/content/1/2/7

[5] Ottoboni, A., & Ottoboni, F. (2013, September 2). The Ketogenic Diet. Retrieved October 15, 2013, from http://ketopia.com/ketogenic-diet/

[6] Phinney, S. (2004). Ketogenic diets and physical performance. Nutr Metab (Lond). Retrieved October 15, 2013, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC524027/