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Coconut Oil: A New Treatment for Alcohol Addiction

coconutoilSource: http://coconutresearchcenter.org/hwnl_10-2/hwnl_10-2.htm

Dry Drunk Syndrome

Roger Hershline, PhD, MD knows the dangers of alcohol abuse firsthand. As a young successful medical professional with a heavy workload, excessive stress drove him to drink as a means of release and relaxation. In time, Roger’s chronic drinking habit led to full-blown alcohol addiction.

His personal life suffered. As with many alcoholics whose marriage and family lives are destroyed, Roger’s life was in shambles. Intoxication and the resulting behavior often lead to fights, jail, and trips to rehabilitation centers. He tried many times to quit, but couldn’t. Feelings of anxiety, depression, and a sense of impending doom when he was sober were relieved only by drinking. His desire to escape led to his use of other drugs.

He finally ended up in federal prison, resulting in a loss of everything dear to him, including his desire to live. Because of his confinement, he was forced into sobriety, but he still suffered from the effects of alcohol addiction. Symptoms of depression, anxiety, irritability, irrational behavior, poor decisions, and cravings for liquor hounded him daily. These symptoms, known as “dry drunk syndrome,” are the reason why most alcoholics do not remain sober. Only from alcohol do they gain relief or achieve feelings of normality. These symptoms can persist indefinitely to some degree after alcohol consumption completely ceases. Even if former alcoholics remain sober, they can wind up living miserable lives and usually make everyone else around them miserable too. Dry drunk syndrome is the downfall of many a recovering alcoholic, even years after they quit drinking. Succumbing to just one drink can drive them into an uncontrollable drinking binge and further alcohol abuse.

There is more to alcoholism than simply a lack of self control or the desire for intoxication. Most alcoholics do not like the consequences of getting drunk and the devastating effects it has on their lives, yet they feel miserable without alcohol. These feelings are real. It is a mental sickness, a personality disorder that causes them to abandon rational judgment and even the sincere desire to stay sober.

Although sober, Roger struggled with the symptoms of dry drunk syndrome. He had already lost everything due to his drinking  problem and didn’t want to repeat past mistakes, so he began to search for a solution to ease his symptoms. His background in medicine led him to investigate alcohol’s effect on brain metabolism. He learned how chronic alcohol consumption can interfere with brain glucose metabolism, which can have a pronounced effect on brain function. He also investigated the importance of nutrition on brain health. His journey to find the best foods to nourish and heal the alcoholic brain led him to coconut oil and to the book,The Coconut Oil Miracle. He started taking coconut oil daily and within four days experienced the same sense of relief from symptoms that he got from alcohol—without the intoxication or the hangover. He experienced a sense of well-being and the ability to think clearly and rationally while sober. Over the next few weeks, he continued with the coconut oil and achieved a complete resolution of the irritability, melancholy, and mental anguish that had plagued him while sober. His dry drunk symptoms and his cravings for alcohol were gone! Nothing else he had ever experienced in his many years with alcohol treatment had come close to matching the effects of using coconut oil.

He enthusiastically began sharing this knowledge with other recovering alcoholics who were struggling with dry drunk syndrome. They, too, experienced the same feelings of well-being and clear thinking that had eluded them during treatment. Roger is now trying to spread the word about this new drug-free treatment for alcohol addiction. Although critics may claim that this treatment is based solely on antidotal evidence, there is good science to back it up.

Alcohol’s Damaging Effects on the Brain

Altered speech, hazy thinking, blurred vision, slowed reaction time, impaired memory: alcohol clearly has a pronounced effect on the brain. Some of these effects are detectable after only one or two drinks then disappear shortly after drinking stops. However, a person who drinks heavily over a long period of time may have brain defects that persist well after he or she becomes sober.

Alcohol is highly soluble in water and when it is consumed, it is absorbed quickly into the bloodstream. Once in the bloodstream, it circulates throughout the body where it can reach every cell in the body. The simple molecular structure of alcohol allows it to pass easily across the blood-brain barrier where it can come into direct contact with brain cells. Here it triggers oxidative stress and inflammation that can seriously affect brain function.1 If more than one or two drinks are consumed it can lead to the symptoms of intoxication.

If heavy drinking becomes chronic, then oxidative stress and inflammation in the brain become chronic. Chronic inflammation can lead to a disruption in normal glucose metabolism.2 Brain cells become insulin resistant and, therefore, cannot absorb glucose effectively.3 The primary source of fuel for the brain is glucose. However, glucose cannot enter the cells without the aid of the hormone insulin. Insulin unlocks the doorway on the cell membrane that allows glucose to enter. Insulin is absolutely essential. Your brain can be saturated with glucose, but if you don’t have insulin, the cells cannot get access to the glucose. If cells cannot get enough glucose to supply their energy needs, the cells degenerate and die. Without glucose, brain cells literally starve to death. This is what happens in the brain of an alcoholic. The damage caused by long term alcoholism can be just as extensive as that caused by Alzheimer’s.

Brain scans using positron emission tomography (PET) on living subjects have shown that intoxication decreases metabolic activity in certain areas of the brain controlling reason, memory, speech, coordination, balance, and vision.4-6 The decreased metabolism indicates a decrease in glucose uptake and conversion into energy. In detoxified alcoholics this decreased metabolism can persist even when the subject is sober.7 Reducing or eliminating alcohol consumption does not reverse alcohol-induced insulin resistance.8 It is insulin resistance and decreased metabolism in the brain that leads to the symptoms associated with dry drunk syndrome.

When alcohol circulates in the bloodstream it eventually passes through the liver, where it is broken down into acetaldehyde—a highly toxic substance that is the primary cause of alcohol-induced liver damage. Acetaldehyde is further broken down into acetic acid, which is a normal metabolite in humans and is nontoxic. About 90 percent of the alcohol consumed is eventually converted into acetic acid. The remaining 10 percent of the alcohol that is not metabolized is excreted in sweat, urine, and expelled in the person’s breath. The latter provides the basis for the breathalyzer test used in law enforcement and the reason you can smell alcohol in a person’s breath after they have been drinking. The liver has a limited capacity for detoxification and can only metabolize 0.25 ounce of pure alcohol per hour, leaving the remaining alcohol to continue its circulation throughout the body.

Although alcohol does not contain any nutrients, it does provide calories—7 calories per gram. This is almost twice as much as either carbohydrate or protein, each of which supplies 4 calories per gram, and just a little less than the 9 calories per gram supplied by fat. The calories from alcohol come from the acetic acid that is produced when alcohol is broken down in the liver.9Acetic acid is a two carbon short chain fatty acid—the smallest of all the fatty acids. It is soluble in both fat and water. In the bloodstream, acetic acid can easily pass through the blood-brain barrier. Like the medium chain fatty acids in coconut oil, acetic acid can diffuse across the cell membrane without the aid of insulin, providing a quick and easy source of energy for cells. In alcoholics, portions of the brain have become insulin resistant and, therefore, cannot effectively absorb glucose. However, the brain cells can absorb acetic acid, which supplies them with an alternative source of energy. Acetic acid partially compensates for the damage caused by alcohol by bypassing the defect in glucose metabolism.

Dr. Roger Hershline believes that the disruption in normal brain metabolism is what leads to the symptoms of dry drunk syndrome. The alcoholic brain, crippled by chronic insulin resistance, is literally starving for energy, causing depression, anxiety, fuzzy thinking, and other symptoms of dry drunk syndrome. Alcohol, although toxic to the brain, increases blood levels of acetic acid, thus providing the brain with a fuel it can use despite being insulin resistant. Repeated drinking has conditioned the brain to know that alcohol consumption increases acetic acid levels, which in turn provides the brain with the energy it desperately needs for survival. The desire for alcohol is a survival mechanism in an attempt to keep brain cells alive. Once this pattern has been set, the alcoholic will have strong desires to drink despite any intellectual or emotional desire to stop.10

In alcoholics, blood levels of acetic acid remain elevated for up to 24 hours after the last drink.11 As acetic acid levels decline, the symptoms and cravings for alcohol gradually return and intensify.

Dr. Hershline’s reasoning in many ways coincides with research coming out of Yale University School of Medicine. Dr. Lihong Jiang and his colleagues at Yale are investigating the use of acetic acid during alcohol detoxification.12 Their approach is to administer acetic acid to the patients as an aid in recovery. Dr. Hershline’s approach, however, appears to be easier and potentially much more effective.

Coconut Ketones and Brain Cell Regeneration

While acetic acid can supply the brain with much needed fuel, consuming alcohol is not a very good way to go about getting it. Acetic acid can be found in various foods. Vinegar is the richest natural source, containing 4-8 percent by volume. Fermented or picked vegetables and many condiments such as ketchup, prepared mustard, and some salad dressings contain acetic acid. But the amount in most condiments is so small that it would have little effect on brain health.

There is a much better option—coconut ketones. Coconut oil is composed primarily of a special group of fats known as medium chain fatty acids (MCFAs). When consumed, a portion of these MCFAs are automatically converted into a highly dense form of energy known as ketones. Like acetic acid, ketones do not require insulin to pass though cell membranes, so they can provide an easy source of energy. Ketones are known as “superfuel” for the brain because they provide more energy than either glucose or acetic acid and are readily absorbed by nerve and brain tissue. Coconut ketones can provide brain cells with a quick and easy source of high potentancy fuel that is superior to acetic acid. By supplying ketones on a regular basis, through the consumption of coconut oil, the brain’s conditioned dependence on acetic acid and desires for alcohol can be broken.

In addition to supplying a superior source of energy, ketones improve blood flow to the brain, improving circulation and oxygen delivery. Ketones also activate certain proteins in the brain called brain derived neurotrophic factors (BDNFs) that regulate brain cell repair, growth, and maintenance. BDNFs stimulate repair of damaged tissues, promote the growth of new brain cells, remove toxins, stop oxidative stress, calm inflammation, and improve insulin sensitivity, all of which allows the brain to heal and recover from injury—including alcohol induced injury.

At one time, it was believed that we could not regenerate new brain cells. The brain cells we were born with, scientists thought, had to last an entire lifetime. When brain cells died, they were gone forever. Research over the past several years has shown that this is not true. The brain can and does generate new cells, even in old age.13 This process is called neurogenesis. These new cells originate from stem cells in the brain. Stem cells are special cells that can divide indefinitely, renew themselves, and give rise to a variety of cells types. The discovery of adult neurogenesis and brain stem cell activation by coconut ketones provides a new way of approaching the problem of alcohol-related changes in the brain and overcoming alcohol addiction.

Dr. Hershline consumed up to 8 tablespoons (109 g) of coconut oil daily in his own treatment. However, blood ketone levels can be raised to therapeutic levels with 5 to 6 tablespoons (68-82 g) daily. The oil should be divided into three 1½ -2 tablespoon doses and should be consumed with foods.

 References

1. Haorah, J., et al. Alcohol-induced oxidative stress in brain endothelial cells causes blood-brain barrier dysfunction. J Leukoc Biol 2005;78:1223-1232.

2. Haiyan, X., et al. Chronic inflammation in fat plays a crucial role in the development of obesity-related insulin resistance. J Clin Invest 2003;112:1821-1830.

3. Ting, J.W. and Lautt, W.W. The effect of acute, chronic, and prenatal ethanol exposure on insulin sensitivity. Pharmacol Ther. 2006;111(2):346–373.

4. Gene-Jack, W., et al. Regional brain metabolism during alcohol intoxication.Alcohol Clin Exp res 2000;24:822-829.

5. Volkow ND, et al. Low doses of alcohol substantially decrease glucose metabolism in the human brain. Neuroimage. 2006;29(1):295–301.

6. Volkow, N.D., et al. Acute alcohol intoxication decreases glucose metabolism but increases acetate uptake in the human brain. Neuroimage. 2013;64:277–283.

7. Volkow, N.D., et al. recovery of brain glucose metabolism in detoxified alcoholics. Am J Psychiatry 1994;151:178-183.

8. Zilkens, R.R., et al. The effect of alcohol lintake on insulin sensitivity in men.Diabetes Care 2003;26:608-612.

9. Patel, A.B., et al. Evaluation of cerebral acetate transport and metabolic rates in the rat brain in vivo using 1H-[13C]-NMR. J Cereb Blood Flow Metab.2010;30(6):1200–1213.

10. Hershline, R. Why Do I Drink?: The Role of Brain Metabolism. Published by Roger Hersline, Hilton Head Island, SC, 2013.

11. Pronko, P.S., et al. Low-molecular-weight metabolites relevant to ethanol metabolism: correlation with alcohol withdrawal severity and utility for identification of alcoholics. Alcohol Alcohol. 1997;32(6):761–768.

12. Lihong, J, et al. Increased brain uptake and oxidation of acetate in heavy drinkers. J Clin Invest 2013; 123:1605-1614.

13. Eriksson, P.S., et al. Neurogenesis in the adult human hippocampus. Nat Med1998;4:1313-1317.

 

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Avocado may be the next Big Anti-Aging Food

Scientists discovered avocado may block free radical damage

May 7, 2012By Mary West

Web-AvocadoGem

Scientists have discovered some impressive, previously unknown health benefits of avocados. This exotic fruit was found to have potent anti-aging properties, in addition to the ability to fight certain diseases due to its unique capacity to protect against free radicals.
This distinctive feature of avocados centers on mitochondria, structures that serve as the power supply of cells. Many environmental pollutants like cigarette smoke and radiation can transform oxygen molecules contained within mitochondria into free radicals, which are destructive unstable molecules. These unstable substances harm cells of many compounds, such as protein, lipids and DNA, changing them into free radicals as well. This detrimental process is linked with aging, and it also plays a role in the development of an array of illnesses.
Since mitochondria play a vital role in free radical damage, researchers have tried unsuccessfully to find antioxidants in fruit and vegetables that can gain entrance into these structures. Without an agent to stop the free radical damage of mitochondria, the destructive process can continue unimpeded within the body.
But a new study found that avocado antioxidants are able to enter mitochondria and boost their energy activity, permitting them to function in a healthy manner even while being vigorously attacked by free radicals. It is this quality that distinguishes avocados from fruits and vegetables containing antioxidants unable to penetrate these energy-producing powerhouses.
The study author Christian Cortés-Rojo compares the effect of avocados to other antioxidants. He provides the analogy of an oil spill, indicating that some measures merely clean up the oil without stopping the escape of the oil from its source. Antioxidants from other food sources could be likened to the measures that help clean up the oil, while antioxidants from avocados could be compared to a measure that actually helps stop the oil flow.
Aside from the exciting benefit of hindering the negative impact of oxygen in the body, avocados have been found to lower cholesterol and help alleviate diabetes. The type of fat present in this fruit is also helpful in fighting many other illnesses, such as heart disease and cancer.
Results of the study were presented at a meeting of the American Society of Biochemistry and Molecular Biology. Because Cortés-Rojo’s team used yeast to investigate the effects of avocados, the author emphasizes the need to confirm the findings in research involving humans.

References:

http://www.redorbit.com/news/health/1112518962/avocado-oil-could-have-anti-aging-disease-fighting-capabilities/
http://www.imperfectparent.com/topics/2012/04/23/avocados-the-next-health-craze/
http://topnews.us/content/247880-avocado-next-super-food
http://paktribune.com/news/Avocados-may-help-keep-you-young-249303.html

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The Comparative Anatomy of Eating

by Milton R. Mills, M.D.

Assoc Director of Preventive Medicine for the Washington, D.C.-based Physicians Committee for Responsible Medicine (PCRM)


Humans are most often described as “omnivores”. This classification is based on the “observation” that humans generally eat a wide variety of plant and animal foods. However, culture, custom and training are confounding variables when looking at human dietary practices. Thus, “observation” is not the best technique to use when trying to identify the most “natural” diet for humans. While most humans are clearly “behavioral” omnivores, the question still remains as to whether humans are anatomically suited for a diet that includes animal as well as plant foods. 

A better and more objective technique is to look at human anatomy and physiology. Mammals are anatomically and physiologically adapted to procure and consume particular kinds of diets. (It is common practice when examining fossils of extinct mammals to examine anatomical features to deduce the animal’s probable diet.) Therefore, we can look at mammalian carnivores, herbivores (plant-eaters) and omnivores to see which anatomical and physiological features are associated with each kind of diet. Then we can look at human anatomy and physiology to see in which group we belong. 

Oral Cavity

Carnivores have a wide mouth opening in relation to their head size. This confers obvious advantages in developing the forces used in seizing, killing and dismembering prey. Facial musculature is reduced since these muscles would hinder a wide gape, and play no part in the animal’s preparation of food for swallowing. In all mammalian carnivores, the jaw joint is a simple hinge joint lying in the same plane as the teeth. This type of joint is extremely stable and acts as the pivot point for the “lever arms” formed by the upper and lower jaws. The primary muscle used for operating the jaw in carnivores is the temporalis muscle. This muscle is so massive in carnivores that it accounts for most of the bulk of the sides of the head (when you pet a dog, you are petting its temporalis muscles). The “angle” of the mandible (lower jaw) in carnivores is small. This is because the muscles (masseter and pterygoids) that attach there are of minor importance in these animals. The lower jaw of carnivores cannot move forward, and has very limited side-to-side motion. When the jaw of a carnivore closes, the blade-shaped cheek molars slide past each other to give a slicing motion that is very effective for shearing meat off bone. 

The teeth of a carnivore are discretely spaced so as not to trap stringy debris. The incisors are short, pointed and prong-like and are used for grasping and shredding. The canines are greatly elongated and dagger-like for stabbing, tearing and killing prey. The molars (carnassials) are flattened and triangular with jagged edges such that they function like serrated-edged blades. Because of the hinge-type joint, when a carnivore closes its jaw, the cheek teeth come together in a back-to-front fashion giving a smooth cutting motion like the blades on a pair of shears. 

The saliva of carnivorous animals does not contain digestive enzymes. When eating, a mammalian carnivore gorges itself rapidly and does not chew its food. Since proteolytic (protein-digesting) enzymes cannot be liberated in the mouth due to the danger of autodigestion (damaging the oral cavity), carnivores do not need to mix their food with saliva; they simply bite off huge chunks of meat and swallow them whole. 

According to evolutionary theory, the anatomical features consistent with an herbivorous diet represent a more recently derived condition than that of the carnivore. Herbivorous mammals have well-developed facial musculature, fleshy lips, a relatively small opening into the oral cavity and a thickened, muscular tongue. The lips aid in the movement of food into the mouth and, along with the facial (cheek) musculature and tongue, assist in the chewing of food. In herbivores, the jaw joint has moved to position above the plane of the teeth. Although this type of joint is less stable than the hinge-type joint of the carnivore, it is much more mobile and allows the complex jaw motions needed when chewing plant foods. Additionally, this type of jaw joint allows the upper and lower cheek teeth to come together along the length of the jaw more or less at once when the mouth is closed in order to form grinding platforms. (This type of joint is so important to a plant-eating animal, that it is believed to have evolved at least 15 different times in various plant-eating mammalian species.) The angle of the mandible has expanded to provide a broad area of attachment for the well-developed masseter and pterygoid muscles (these are the major muscles of chewing in plant-eating animals). The temporalis muscle is small and of minor importance. The masseter and pterygoid muscles hold the mandible in a sling-like arrangement and swing the jaw from side-to-side. Accordingly, the lower jaw of plant-eating mammals has a pronounced sideways motion when eating. This lateral movement is necessary for the grinding motion of chewing.

The dentition of herbivores is quite varied depending on the kind of vegetation a particular species is adapted to eat. Although these animals differ in the types and numbers of teeth they posses, the various kinds of teeth when present, share common structural features. The incisors are broad, flattened and spade-like. Canines may be small as in horses, prominent as in hippos, pigs and some primates (these are thought to be used for defense) or absent altogether. The molars, in general, are squared and flattened on top to provide a grinding surface. The molars cannot vertically slide past one another in a shearing/slicing motion, but they do horizontally slide across one another to crush and grind. The surface features of the molars vary depending on the type of plant material the animal eats. The teeth of herbivorous animals are closely grouped so that the incisors form an efficient cropping/biting mechanism, and the upper and lower molars form extended platforms for crushing and grinding. The “walled-in” oral cavity has a lot of potential space that is realized during eating. 

These animals carefully and methodically chew their food, pushing the food back and forth into the grinding teeth with the tongue and cheek muscles. This thorough process is necessary to mechanically disrupt plant cell walls in order to release the digestible intracellular contents and ensure thorough mixing of this material with their saliva. This is important because the saliva of plant-eating mammals often contains carbohydrate-digesting enzymes which begin breaking down food molecules while the food is still in the mouth. 

Stomach and Small Intestine


Striking differences between carnivores and herbivores are seen in these organs. Carnivores have a capacious simple (single-chambered) stomach. The stomach volume of a carnivore represents 60-70% of the total capacity of the digestive system. Because meat is relatively easily digested,
their small intestines (where absorption of food molecules takes place) are short — about three to five or six times the body length. Since these animals average a kill only about once a week, a large stomach volume is advantageous because it allows the animals to quickly gorge themselves when eating, taking in as much meat as possible at one time which can then be digested later while resting. Additionally, the ability of the carnivore stomach to secrete hydrochloric acid is exceptional. Carnivores are able to keep their gastric pH down around 1-2 even with food present. This is necessary to facilitate protein breakdown and to kill the abundant dangerous bacteria often found in decaying flesh foods. 

Because of the relative difficulty with which various kinds of plant foods are broken down (due to large amounts of indigestible fibers), herbivores have significantly longer and in some cases, far more elaborate guts than carnivores. Herbivorous animals that consume plants containing a high proportion of cellulose must “ferment” (digest by bacterial enzyme action) their food to obtain the nutrient value. They are classified as either “ruminants” (foregut fermenters) or hindgut fermenters. The ruminants are the plant-eating animals with the celebrated multiple-chambered stomachs. Herbivorous animals that eat a diet of relatively soft vegetation do not need a multiple-chambered stomach. They typically have a simple stomach, and a long small intestine. These animals ferment the difficult-to-digest fibrous portions of their diets in their hindguts (colons). Many of these herbivores increase the sophistication and efficiency of their GI tracts by including carbohydrate-digesting enzymes in their saliva. A multiple-stomach fermentation process in an animal which consumed a diet of soft, pulpy vegetation would be energetically wasteful. Nutrients and calories would be consumed by the fermenting bacteria and protozoa before reaching the small intestine for absorption. The small intestine of plant-eating animals tends to be very long (greater than 10 times body length) to allow adequate time and space for absorption of the nutrients. 

Colon

The large intestine (colon) of carnivores is simple and very short, as its only purposes are to absorb salt and water. It is approximately the same diameter as the small intestine and, consequently, has a limited capacity to function as a reservoir. The colon is short and non-pouched. The muscle is distributed throughout the wall, giving the colon a smooth cylindrical appearance. Although a bacterial population is present in the colon of carnivores, its activities are essentially putrefactive. 

In herbivorous animals, the large intestine tends to be a highly specialized organ involved in water and electrolyte absorption, vitamin production and absorption, and/or fermentation of fibrous plant materials. The colons of herbivores are usually wider than their small intestine and are relatively long. In some plant-eating mammals, the colon has a pouched appearance due to the arrangement of the muscle fibers in the intestinal wall. Additionally, in some herbivores the cecum (the first section of the colon) is quite large and serves as the primary or accessory fermentation site. 

What About Omnivores?

One would expect an omnivore to show anatomical features which equip it to eat both animal and plant foods. According to evolutionary theory, carnivore gut structure is more primitive than herbivorous adaptations. Thus, an omnivore might be expected to be a carnivore which shows some gastrointestinal tract adaptations to an herbivorous diet. 

This is exactly the situation we find in the Bear, Raccoon and certain members of the Canine families. (This discussion will be limited to bears because they are, in general, representative of the anatomical omnivores.) Bears are classified as carnivores but are classic anatomical omnivores. Although they eat some animal foods, bears are primarily herbivorous with 70-80% of their diet comprised of plant foods. (The one exception is the Polar bear which lives in the frozen, vegetation poor arctic and feeds primarily on seal blubber.) Bears cannot digest fibrous vegetation well, and therefore, are highly selective feeders. Their diet is dominated by primarily succulent lent herbage, tubers and berries. Many scientists believe the reason bears hibernate is because their chief food (succulent vegetation) not available in the cold northern winters. (Interestingly, Polar bears hibernate during the summer months when seals are unavailable.) 

In general, bears exhibit anatomical features consistent with a carnivorous diet. The jaw joint of bears is in the same plane as the molar teeth. The temporalis muscle is massive, and the angle of the mandible is small corresponding to the limited role the pterygoid and masseter muscles play in operating the jaw. The small intestine is short ( less than five times body length) like that of the pure carnivores, and the colon is simple, smooth and short. The most prominent adaptation to an herbivorous diet in bears (and other “anatomical” omnivores) is the modification of their dentition. Bears retain the peg-like incisors, large canines and shearing premolars of a carnivore; but the molars have become squared with rounded cusps for crushing and grinding. Bears have not, however, adopted the flattened, blunt nails seen in most herbivores and retain the elongated, pointed claws of a carnivore. 

An animal which captures, kills and eats prey must have the physical equipment which makes predation practical and efficient. Since bears include significant amounts of meat in their diet, they must retain the anatomical features that permit them to capture and kill prey animals. Hence, bears have a jaw structure, musculature and dentition which enable them to develop and apply the forces necessary to kill and dismember prey even though the majority of their diet is comprised of plant foods. Although an herbivore-style jaw joint (above the plane of the teeth) is a far more efficient joint for crushing and grinding vegetation and would potentially allow bears to exploit a wider range of plant foods in their diet, it is a much weaker joint than the hinge-style carnivore joint. The herbivore-style jaw joint is relatively easily dislocated and would not hold up well under the stresses of subduing struggling prey and/or crushing bones (nor would it allow the wide gape carnivores need). In the wild, an animal with a dislocated jaw would either soon starve to death or be eaten by something else and would, therefore, be selected against. A given species cannot adopt the weaker but more mobile and efficient herbivore-style joint until it has committed to an essentially plant-food diet test it risk jaw dislocation, death and ultimately, extinction. 

What About Me?

The human gastrointestinal tract features the anatomical modifications consistent with an herbivorous diet. Humans have muscular lips and a small opening into the oral cavity. Many of the so-called “muscles of expression” are
actually the muscles used in chewing. The muscular and agile tongue essential for eating, has adapted to use in speech and other things. The mandibular joint is flattened by a cartilaginous plate and is located well above the plane of the teeth. The temporalis muscle is reduced. The characteristic “square jaw” of adult males reflects the expanded angular process of the mandible and the enlarged masseter/pterygoid muscle group. The human mandible can move forward to engage the incisors, and side-to-side to crush and grind. 

Human teeth are also similar to those found in other herbivores with the exception of the canines (the canines of some of the apes are elongated and are thought to be used for display and/or defense). Our teeth are rather large and usually abut against one another. The incisors are flat and spade-like, useful for peeling, snipping and biting relatively soft materials. The canines are neither serrated nor conical, but are flattened, blunt and small and function Like incisors. The premolars and molars are squarish, flattened and nodular, and used for crushing, grinding and pulping noncoarse foods. 

Human saliva contains the carbohydrate-digesting enzyme, salivary amylase. This enzyme is responsible for the majority of starch digestion. The esophagus is narrow and suited to small, soft balls of thoroughly chewed food. Eating quickly, attempting to swallow a large amount of food or swallowing fibrous and/or poorly chewed food (meat is the most frequent culprit) often results in choking in humans. 

Man’s stomach is single-chambered, but only moderately acidic. (Clinically, a person presenting with a gastric pH less than 4-5 when there is food in the stomach is cause for concern.) The stomach volume represents about 21-27% of the total volume of the human GI tract. The stomach serves as a mixing and storage chamber, mixing and liquefying ingested foodstuffs and regulating their entry into the small intestine. The human small intestine is long, averaging from 10 to 11 times the body length. (Our small intestine averages 22 to 30 feet in length. Human body size is measured from the top of the head to end of the spine and averages between two to three feet in length in normal-sized individuals.) 

The human colon demonstrates the pouched structure peculiar to herbivores. The distensible large intestine is larger in cross-section than the small intestine, and is relatively long. Man’s colon is responsible for water and electrolyte absorption and vitamin production and absorption. There is also extensive bacterial fermentation of fibrous plant materials, with the production and absorption of significant amounts of food energy (volatile short-chain fatty acids) depending upon the fiber content of the diet. The extent to which the fermentation and absorption of metabolites takes place in the human colon has only recently begun to be investigated. 

In conclusion, we see that human beings have the gastrointestinal tract structure of a “committed” herbivore. Humankind does not show the mixed structural features one expects and finds in anatomical omnivores such as bears and raccoons. Thus, from comparing the gastrointestinal tract of humans to that of carnivores, herbivores and omnivores we must conclude that humankind’s GI tract is designed for a purely plant-food diet.

Summary

Humans are biologically herbivores
Carnivores
Omnivores
Herbivores
Humans
Facial muscles
Reduced to allow wide mouth gape Reduced Well-developed Well-developed
Jaw type
Angle not expanded Angle not expanded Expanded angle Expanded angle
Jaw joint location
On same plane as molar teeth On same plane as molar teeth Above the plane of the molars Above the plane of the molars
Jaw motion
Shearing; minimal side-to-side motion Shearing; minimal side-to-side motion No shear; good side-to-side, front-to-back No shear; good side-to-side, front-to-back
Major jaw muscles
Temporalis Temporalis Masseter and ptergoids Masseter and pterygoids
Mouth opening vs. head size
Large Large Small Small
Teeth: Incisors
Short and pointed Short and pointed Broad, flattened and spade-shaped Broad, flattened and spade-shaped
Teeth: Canines
Long, sharp, and curved Long, sharp and curved Dull and short or long (for defense), or none Short and blunted
Teeth: Molars
Sharp, jagged and blade-shaped Sharp blades and/or flattened Flattened with cusps vs. complex surface Flattened with nodular cusps
Chewing
None; swallows food whole Swallows food whole and/or simple crushing Extensive chewing necessary Extensive chewing necessary
Saliva
No digestive enzymes No digestive enzymes Carbohydrate digesting enzymes Carbohydrate digesting enzymes
Stomach type
Simple Simple Simple or multiple chambers Simple
Stomach acidity with food in stomach
≤ pH 1 ≤ pH 1 pH 4-5 pH 4-5
Length of small intestine
3-6 times body length 4-6 times body length 10-12+ times body length 10-11 times body length
Colon
Simple, short, and smooth Simple, short, and smooth Long, complex; may be sacculated Long, sacculated
Liver
Can detoxify vitamin A Can detoxify vitamin A Cannot detoxify vitamin A Cannot detoxify vitamin A
Kidney
Extremely concentrated urine Extremely concentrated urine Moderately concentrated urine Moderately concentrated urine
Nails
Sharp claws Sharp claws Flattened nails or blunt hooves Flattened nails
From The Comparative Anatomy of Eating (PDF), by Milton R. Mills, M.D.