HUMAN GROWTH HORMONE RESEARCH & NEWS

In general, Metabolism refers to the chemical reactions that create a living being. Scientifically, it's a very broad term. In general terms, however, Metabolism refers to the human processes which sustain energy and burn fat in the human body.

Our metabolism is at its highest when we are young. In our adolescence and teens, boys and girls often seem to have bottomless stomachs, especially if they engage in any reasonable level of physical activity. Metabolism remains very high during the twenties as well. Around the age of twenty five, however, natural metabolism starts to drop.

After twenty five, you can expect your metabolism to drop somewhere between five and ten percent every decade, if you maintain the same level of activity. In the United States, the average adult loses somewhere between twenty and forty percent of their metabolism over the course of their adult life.

The good thing about metabolism is that it is heavily influenced by your choices and your activity level. There are a number of things that you can do to enhance your metabolism and increase your muscle building and fat burning power.

The rest of this article will provide you with some helpful tips that you can use in your day-to-day life to increase your metabolism naturally!

Tip One: Improve Your Sleeping Habits

One of the biggest factors which will control your overall metabolism is sleep. Numerous studies have shown that poor sleeping habits and sleeping patterns have a negative impact upon your overall metabolism. There are a couple of big reasons for this. One reason is that your Human Growth Hormone Production is intimately tied to healthy, deep sleep, and Low HGH Levels reduce your metabolism.

Another reason that Poor Sleeping Habits negatively impact metabolism is because the less sleep that you get, the more that you tend to eat. One study found that individuals that slept only five hours per night gained two pounds per week, compared to individuals that slept nine hours, who stayed at a stable weight.

Tip Two: Start Drinking Green Tea

Green Tea is a great drink for people that want to lose weight and increase metabolism. One reason why Green Tea is a great choice is because it has a powerful and delicious flavor while also being a zero-calorie drink. Green Tea is a completely guilt free beverage, and if you really need to add sweetener, there are sugar substitutes like Stevia which have no negative impact on health while also being a fine substitute for sugar.

This beverage is also an awesome choice for dieters because it is loaded with antioxidants, which both have the capability to preserve your health at the cellular level while also boosting your metabolism. Researchers found that the antioxidants contained within Green Tea have a direct positive impact on fat metabolism, and burn energy even when taking into account the caffeine content of the drink. Researchers found that healthy males that drank Green Tea had metabolisms which were around four percent higher than males that did not.

Tip Three: Intensify Your Workouts

All forms of exercise are good at increasing your metabolism, whether you are walking, jogging, or lifting weights. There are some forms of exercise that are more effective at boosting metabolism than others, however. The most effective means to increase metabolism through exercise is with a strategy known as High-Intensity Interval Training. This means that when you perform your normal exercises, you should incorporate sprints or other exercises which rely on bursts of energy.

One reason why these forms of exercise are so effective at increasing metabolism is that High Intensity Cardio and Weight Lifting have the ability to greatly increase your Human Growth Hormone Secretion. Although Human Growth Hormone is released at its highest levels while you are asleep, the hormone is also released in high quantities when you perform these intense exercises. By engaging in these exercises, you can kick-start your metabolism both during exercise and for hours afterward, increasing the weight loss and muscle building potential of your workout routine.

Tip Four: Never Miss Breakfast

Although Breakfast is no longer considered the most important meal of the day, the meal is incredibly important in regard to your metabolism. Even eating a small breakfast has a positive impact on your overall metabolism through the day. While you sleep, your body builds up cortisol levels until the levels reach a point which rouses you from your bed. Breakfast is like a reset button on these cortisol levels which energizes you with the calories contained within.

It's also beneficial to your metabolism never to have a heavy meal just before bed. Your body's metabolism slows to a crawl while you sleep, and more of the calories you consume are converted into fat. Late night meals also get your hormone balance out of whack and can make it even harder to get up in the morning.

Tip Five: Start Lifting Weights

In addition to High-Intensity Interval Training, just simple weight lifting has some impressive effects in regard to metabolism. Although you won't be maximizing your metabolic output with simple anaerobic training, you will increase the size and strength of your muscles, which will have positive benefits upon metabolism over time.

Weight lifting is also a powerful way to immediately burn calories. If you engage in a thorough weight lifting regimen, you can even burn as many calories as you would running. Combining both running and weight lifting provides the most significant benefits to your health, because running or other forms of cardiovascular exercise get your blood pumping, and weight lifting burns large amounts of stored energy.

Tip Six: Drink Lots of Water

One of the simplest ways to enhance your metabolism is to simply make sure you get a healthy level of water every day. There are a lot of good ways to do this, and don't think you are beholden to simply drinking water, but avoid sodas and other drinks that have a tendency to dehydrate! Studies have shown that people that remain fully hydrated with water throughout the day lose weight more quickly than those who do not.

One study found that after drinking a glass of water, metabolism increased around thirty percent in both male and female patients. The increase in metabolism initiated around ten minutes after consumption, and metabolism remained enhanced for thirty to forty minutes after drinking. One interesting outcome of the study was that researchers found that male subjects primarily increased fat metabolism, whereas female patients primarily saw an increase in carbohydrate metabolism.

Tip Seven: Add Spice to Your Meals

You may have heard the myth, but we just wanted to confirm that it is true. Spicy seasonings do have the ability to increase your metabolism. One of the simplest ways to increase your metabolic rate is to add a little cayenne pepper or some other form of spicy seasoning containing Capsaicin.

Studies have shown that adding seasonings containing Capsaicin has the capability to increase your metabolic rate by around eight percent on average. Capsaicin also benefits healthy eaters because it helps you feel more full more quickly.

Another study showed that males that consumed appetizers which contained hot sauce tended to eat an average of two hundred calories less than men that did not. Capsaicin is also recognized for having anti-inflammatory benefits, as well as for increasing blood flow and opening up blood vessels.

Tip Eight: Engage in Regular Cardiovascular Activity

Cardiovascular exercise is also another potent means to enhance metabolism. Cardio has the ability to increase metabolism for an extended period of time. One clinical study revealed that a forty-five minute bike ride had the capacity to increase metabolism over the course of the next twelve hours.

It's also easy to combine High-Intensity Interval Training into your cardiovascular exercise. At regular intervals in your cardio, enter a sprinting speed in order to engage your anaerobic muscle tissue and squeeze out extra energy burning power. A healthy exercise routine which combines cardio, High-Intensity Interval Training, and Weight Training will produce the maximum level of benefit. And don't forget to drink plenty of water!

Tip Nine: Start Drinking Coffee!

Okay, we realize that a lot of you already drink coffee, but did you know that coffee is highly effective at enhancing your metabolism? Coffee is a highly efficient means to get a jolt of caffeine without downing too many unnecessary calories. Coffee also delivers caffeine to the body quickly, and metabolism will slowly increase to a peak after around three hours. The caffeine in coffee increases your heart rate, which boosts your calorie-burning power.

Coffee also contains a few other natural ingredients which have the capability to increase metabolism. One of them is Chlorogenic Acid. This chemical has been shown to slow down the rate at which carbohydrates are absorbed, increasing the energy available to burn. Coffee also has two other chemicals which function very similarly to caffeine: Theophylline and Theobromine.

Tip Ten: Start Laughing!

In recent years, researchers have started to unlock the mystery of laughter. One reason that laughter is beneficial is because it acts as a natural stress reliever. Laughter is a physiological sign that you are at ease and you have your guard down. Laughter also produces benefits within the body. It opens up the blood vessels and allows blood to flow more freely through the body.

Laughter also increases metabolism, because it both engages the muscles and encourages optimal circulation. It doesn't take a lot of laughter to produce significant benefits either. Studies have shown that around ten minutes of laughter each day is sufficient to significantly boost metabolic rate as well as feelings of well-being. Give in to laughter, your body will thank you for it.

Dopamine Hormone Guide

Dopamine is a hormone that serves many complex purposes throughout the body, although it is most well-known for its impact on reward and addiction. Dopamine belongs to both the phenethylamine and catacholamine families. Drugs from the phenethylamine family are known for their stimulant effects as well as their psychoactive effects. Catecholamines are hormones which alter the overall activity level of the central nervous system.

How Did Dopamine Get Its Name?

Dopamine gets its name directly from its chemical structure. Dopamine is an amine, meaning that it is a nitrogen-based organic molecule. Dopamine is formed when an L-DOPA molecule loses its carboxyl group. Dopamine is active both in the brain and in the peripheral systems of the body, but Dopamine acts independently as released in both contained systems.

What is the Function of Dopamine in the Brain?

Dopamine is a hormone that sends messages to other parts of the brain, also known as a neurotransmitter. There are a number of areas of the brain that are activated by Dopamine, most notably, the area associated with desire and reward, but the hormone is associated with a wide variety of other physiological actions as well.

The majority of things that we, as humans, find rewarding—delicious food, sex, drugs—cause this dopamine-based reward system to be activated. Things that are addictive have the ability to fire off these pleasure centers to an extent where the body and mind begin to crave further stimulation.

Dopamine is also related to other activities in the brain, however. It stimulates the release of other hormones, and it helps control movement. There are a number of neurological motor disorders associated with Dopamine dysfunction, including Parkinson's disease.

Parkinson's disease is a neurological, degenerative condition which causes the body to shake near-uncontrollably, while also slowly leading to immobility over time. Parkinson's is caused when the substantia nigra no longer produces the Dopamine which helps regulate motor activity.

Although Parkinson's is a chronic, degenerative disorder, it can be treated with drugs which increase the concentration of Dopamine in the brain. These drugs are also known as antipsychotics.

Other conditions which are hypothesized to be associated with dopamine-inhibition are Restless Legs Syndrome and ADHD.

What Is the Function of Dopamine in the Human Body?

Dopamine is highly active in the brain, but it also serves a number of purposes in the peripheral systems of the body, where it acts as a hormonal messenger.

• In the cardiovascular system, dopamine blocks the release of norepinephrine, causing the blood vessels to open up.

• In the renal system, the hormone encourages urination and the evacuation of sodium.

• Dopamine inhibits the production of insulin by the pancreas

• In the gastrointestinal system, Dopamine slows down the rate at which foods pass through the system, and it also helps protect the lining of the intestines.

• In the immune system, Dopamine slows down the activity of white blood cells.

Aside from the cardiovascular system, all peripheral effects of Dopamine are considered paracrine activity—this means that Dopamine is released in the immediate vicinity of where it is absorbed by nearby cells, exerting its influence.

How do Medications Affect the Release of Dopamine?

Because of the importance of the hormone, there are a variety of drugs available which affect the way that the body secretes or utilizes Dopamine. Bio-Identical Dopamine Injections are a common form of treatment, but Dopamine, when administered intravenously, is incapable of passing through the blood-brain barrier. Dopamine is frequently used as an emergency treatment for patients suffering from shock or heart failure, for example.

Because there is no way to directly deliver Dopamine to the brain, the most effective way to increase Dopamine levels via medication is through the Dopamine precursor, L-DOPA. L-DOPA does have the ability to pass through the blood brain barrier, and is one of the most common treatments for Parkinson's, because it can suppress tremors by providing Dopamine to struggling areas of the brain.

Drugs which stimulate Dopamine are almost always addictive in high quantities, but they are effective at modest doses to alleviate ADHD. Antipsychotics, on the other hand, are medications which suppress the activity of Dopamine in the body. There are similar drugs that suppress Dopamine through other means that are highly effective at treating nausea.

Dopamine and the Brain

The area of the brain that is central to the body's physiological reward system is located in the ventral tegmental area, and nerves in this region secrete dopamine in response to or in preparation of reward. After Dopamine is produced it travels to the prefrontal cortex and the nucleus accumbens.

Dopamine also controls motor ability, but does so through a different mechanism which does not interact directly with the pleasure pathway. In order to help control movement, Dopamine is released by neurons in the substantia nigra, and the hormone travels to the striatum. The striatum is responsible for our mind's ability to control our movements, and it also allows for fine motor function by suppressing the body's minor conscious movements to enhance control. It also plays a role in social inhibition.

Dopamine Transmitters

Dopamine is a hormone which plays a wide variety of roles. It is a reward mechanism, it stimulates cognition, motivation, arousal, and physical self-control. There are a number of automatic functions that are related to Dopamine as well, such as the sensations of nausea and sexual pleasure, as well as lactation.

Perhaps surprisingly, there aren't a whole lot of neurons in the brain that are dedicated primarily to Dopamine production. In fact, the entire brain only has about 400,000 of these neurons, and they are located in very particular areas of the brain. In spite of their small number, they have a widespread impact on physiological function.

Areas of the Brain Which Release Dopamine

The Substantia Nigra - Dopamine and Fine Motor Control

As we mentioned earlier, Dopamine plays a vital role in the body's ability to control its movements. Dopamine exerts control over motor function through the substantia nigra, which is an area of dark brain tissue that is attached to the basal ganglia. Most of the Dopamine neurons in the substantia nigra are located in an area known as the pars compacta.

The cells which emit Dopamine in this area can become damaged quite easily, and if a large portion of these cells die, it brings about symptoms that are very similar to Parkinson's Disease.

The Ventral Tegmental Area - Dopamine, Motivation, and Reward

Another area of the brain with dense Dopamine activity is the ventral tegmental area. It is this area of the brain that is responsible for providing the psyche with motivation. Researchers have actually noted that the actions of Dopamine in the ventral tegmental area affect psychological motivation in a similar manner that the nucleus accumbens affects the fine control of motor activity. This means that the ventral tegmental area is also responsible for controlling fine cognitive activity as well, including the mind's ability to make decisions.

Dopamine and the Hypothalamus

There are also cells which produce Dopamine which are located in the posterior hypothalamus, which extend into the spinal cord, but medical researchers are not completely sure how Dopamine impacts the body through this route. There is evidence backing the hypothesis that this Dopamine pathway controls the suppression of motor movement in the body, and those with Restless Legs Syndrome suffer from Dopamine Deficiency in this area of the brain. Restless Legs Syndrome makes it hard to sleep, resulting from the unconscious movements of the body, which is most severe in the legs.

Dopamine and Lactation

Dopamine Neurons in the Periventricular Nucleus and the Arcuate Nucleus suppress the release of breast milk, which is encouraged through the release of prolactin. Dopamine produced in this part of the brain flows into the pituitary gland. The body produces Dopamine as a means to prevent lactation, and when mothers prepare to nurse, this pathway suppresses the production of Dopamine, which allows lactation to take place.

When discussed in the context of this system, Dopamine is often referred to by other names, including Prolactostatin, Prolactin-Inhibiting Hormone, or Prolactin-Inhibiting Factor

Dopamine, Puberty, and Sex Hormone Production

This area of the brain is tightly interconnected with the Hypothalamus. In order for the body to produce sex hormones, Dopamine is released from the Zona Incerta into the Hypothalamus, where the hormone encourages the production of Gonadotropin-Releasing Hormone. The number of Dopamine Receptors in the brain increases dramatically during this period, which helps encourage the rapid onset of sexual changes associated with puberty.

Dopamine and Eyesight

Dopamine also plays a role in eyesight. During the day, amacrine cells in the retina produce Dopamine which simultaneously increases the receptivity of cone cells while reducing the influence of rods. This mechanism makes it easier to see during the day. At night, Dopamine production in this area declines, making it easier to see in dim light.

Dopamine Activity In the Body

As Dopamine is unable to cross from the blood stream into the brain, any Dopamine that is produced by the peripheral systems of the body has no direct impact on Dopamine activity within the brain. There is a lot of Dopamine that travels through the circulatory system, but researchers are still learning how Dopamine impacts the physiology of the body via this pathway.

Some Dopamine is absorbed through the diet, but the body converts this Dopamine into a different form that researchers have discovered no use for. This form of Dopamine is eventually released after it is filtered out by the kidneys.

It is believed that an active form of Dopamine is produced by certain organs, including those in the digestive system and those in the sympathetic nervous system. Physiologically active Dopamine can go through a number of processes in the body. It is sometimes converted by the adrenal glands into norepinephrine, an important hormone which regulates fight-or-flight mechanisms. It can also activate receptor sites throughout the body, or can simply be metabolized.

There are numerous receptors for Dopamine in the arteries. Dopamine activity in this area suppresses the production of norepinephrine and opens up the arteries.

Dopamine and the Immune System

Dopamine has a powerful effect upon the immune system, especially upon the circulatory system, bone marrow, and the spleen. Also, Dopamine suppresses the activity of white blood cells. Cells in the immune system have the ability to release Dopamine, so it is believed that Dopamine helps prevent the white blood cells from going into overdrive.

Dopamine and the Renal System

There are a number of locations in the kidneys that react with Dopamine, and Dopamine is actually produced by the kidneys by tubule cells. Dopamine serves a number of purposes in this system. It encourages filtration, helps draw sodium from the blood stream, and enhances blood flow to the organ. If the kidneys lose their ability to effectively produce Dopamine, this can lead to issues such as hypertension and elevated sodium levels.

Dopamine and the Pancreas

Dopamine plays an intricate role in the function of the pancreas. The pancreas has two sections, the endocrine area and the exocrine area. The exocrine section of the pancreas helps control digestion, releasing substances such as enzymes into the digestive tract to help break down and absorb food. Dopamine plays a role in this process, although researchers are not completely sure of its function. Researchers hypothesize that Dopamine both slows down the rate at which the body processes food and also preserves the inner lining of the intestines.

The areas of the pancreas which regulates internal health are known as the islets of Langerhans. This area is responsible for the production of hormones that are released into the blood stream, one of which is insulin. The cells within the islets of Langerhans which produce insulin are known as beta cells, and it is believed that these cells are receptive to the influence of Dopamine, and that Dopamine activation suppresses the production of insulin.

Dopamine and Risk

There is a strong correlation between Dopamine levels in the brain and one's desire and ability to take risks. Individuals with lower levels of Dopamine activity in the brain tend to be more cautious and are less likely to seek out risk, while individuals with high levels of natural Dopamine production are more likely to enjoy and thrive on risk.

Dopamine is the reason why, when we do something that takes effort and risk, it elicits a feeling of satisfaction. Dopamine encourages us to go outside of our comfort zone and do things we normally wouldn't do. It causes one to thrive on risk, experiencing a literal high when they meet their goals. This often causes them to seek out larger and larger risks, as their surmounted risks are no longer as exciting.

The difference in Dopamine levels among different groups of people explains why some people are happy with comfortable lives and are risk averse, while others seem to thrive on the sensations associated with risk.

Part of what controls Dopamine activity in the brain is the existence of what are known as autoreceptors. Autoreceptors bind with Dopamine and reduce their activity in the body. Researchers have found that people that enjoy risk have fewer of these Dopamine inhibitors, which causes them to be more interested in engaging in risk-taking.

Many people are addicted to Adrenaline. This is the sensation that happens when we ride roller coasters or get in dangerous situations. Adrenaline rewards risky behaviors, but it doesn't reward stepping out of one's comfort zone, necessarily. Whereas Adrenaline makes people love driving fast and getting into fights, Dopamine makes people want to engage in pursuits which might deter others. Dopamine doesn't engage the fight-or-flight response, it simply causes a person to downplay risks and be more likely to engage in out-of-the-box activities.

Dopamine and Depression

Dopamine deficiency is associated with an increased incidence of depression. Robin Williams recent passing is perhaps a testament to this connection. After Robin Williams committed suicide, it was revealed by his wife that Robin was struggling with the initial stages of Parkinson's disease. As we've discussed, Parkinson's is a medical disorder which is caused when the motor area of the brain no longer produces enough Dopamine to regulate motor movement, which leads to the tremors and shaking associated with the disorder.

Reduced Dopamine levels also can lead to depression, because the reward system of the brain is not as active. The body and mind simply do not experience pleasure in the same way, and this increases the likelihood of depression. In Williams' case, depression led him to suicide.

Dopamine also controls one's sense of motivation. In many cases when people truly want to do something but can't generate the willpower, this is a result of Dopamine Deficiency.

Parkinson's Disease and Depression are independent disorders, but one is more likely to occur when the other is present. The conditions also play off of each other and can worsen the effects of both for the patient. The combination leads to feelings of intense isolation and anxiety, which can be incredibly difficult to overcome.

References:

Dopamine Wiki:

http://en.wikipedia.org/wiki/Dopamine

The Mystery of Risk:

http://ngm.nationalgeographic.com/2013/06/125-risk-takers/gwin-text

Dopamine Regulates Motivation to Act, Study Shows:

http://www.sciencedaily.com/releases/2013/01/130110094415.htm

Serotonin Hormone Guide

What is Serotonin?

Serotonin is an important hormone that regulates a wide variety of functions in the body, and is most notable for its effects upon mood and well-being. Serotonin is found in a number of areas of the body, including the brain, central nervous system, platelets and digestive system. Serotonin is synthesized by the body from a hormone known as tryptophan, which most people recognize as the hormone in turkey and many other foods that makes us sleepy. Maintaining Serotonin balance is a vitally important aspect of promoting both the health of the brain and the health of the body.

Effects of Serotonin both Psychological and Physiological

Perhaps contrary to popular belief, the vast majority of serotonin that is produced by the body is secreted into the digestive system, in order to promote motility in the intestinal track. Around ninety percent of the serotonin released by the body serves this purpose.

When Serotonin is released by the digestive system, it acts upon the intestines and drains out into the blood stream over time. Platelets actually have the ability to absorb this Serotonin, and use it for their own purposes. Platelets are cells in the blood stream that don't have nuclei which are primarily used as a clotting mechanism. When the platelets begin to form a blood clot, they emit their stored serotonin, which shrinks blood vessels in the surrounding area in order to control blood flow and help stop circulatory leakage.

Serotonin also promotes cellular metabolism in certain types of tissue, and it is hypothesized that the hormone helps speed up healing in the case of injury.

Neurological Effects of Serotonin

Aside from the digestive system, the second most active area for Serotonin production is the central nervous system, where the hormone impacts physiological activity in a variety of ways. Serotonin impacts a number of regulatory systems in the brain, including sleep, appetite, and mood.

Serotonin also has some influences on learning, memory, and other cognitive abilities. There are a number of antidepressant medications that function by altering the way that the body responds to Serotonin, including Selective Serotonin Reuptake Inhibitors (SSRIs).

Serotonin in Nature

Serotonin is not only found in humans and animals, but also in plants and fungi. Serotonin actually has the ability to promote a pain response under some circumstances, and the hormone often coats the barbs of plants and is often a component of venom in insects. In fact, when Serotonin is administered via injection, it can sometimes cause pain to the patient, as if they were bitten or stung.

Serotonin and Digestive Health

There are also instances where Serotonin is produced by organisms within the digestive system. For example, there are amoeba which can replicate in the stomach and intestines, which release Serotonin, speeding up the digestive tract, which leads to diarrhea. Also, Serotonin is present in many fruits and seeds, which causes the digestive system to pass seeds more effectively.

Serotonin Produced by All Complex Animals

Serotonin is an important neural hormone and is produced by all animals with bilateral symmetry. Dependent upon the complexity of the organism, Serotonin serves an increasingly larger role in the nervous system. In simple animals like invertebrates, Serotonin primarily helps the organism to recognize the abundance of food in a particular area.

In more evolved animals, like vertebrates and arthropods, Serotonin not only evaluates food resources, but also plays a role in social interactions, including dominance and submission. Because reproduction and the viability of young depend on food availability, Serotonin contributes to the production of sex hormones and the motivation to breed. Serotonin also has a powerful impact on growth and mood.

Serotonin, Depression, and Obsessive Compulsive Disorder

Serotonin plays a complex role in maintaining healthy emotional balance in human beings. People that don't produce enough Serotonin are both more likely to suffer from depression and more likely to suffer from compulsive thoughts. Related to the mechanisms of Serotonin, people that don't produce enough Serotonin are more likely to engage in risky activities, including promiscuous sex and self-harm.

There is some clinical evidence that Depression inhibits the brain's ability to produce new neurons in the brain, which suppresses activity in certain parts of the brain, in particular, those related to mood stability and well-being. It is believed that SSRIs have the ability to restore Serotonin Levels in the brain, encouraging the rejuvenation of brain cells, which helps the mind recover from depression and generally improve quality of life from a psychological perspective.

It is unclear, however, whether Serotonin Deficiency leads to depression or if it is perhaps the other way around. Of course, depending on the particulars of the patient, either or both of these issues could be at play. In patients that experience chronic depression and OCD from an early age, the cause would primarily be neurological, whereas in patients that experience depression later in life, the cause is much more likely to be the result of circumstances in their lives.

How Do SSRIs Treat Psychological Disorders such as Depression and OCD?

One of the most common treatments for both OCD and Depression is the prescription of a Selective Serotonin Reuptake Inhibitor. These medications increase the activity of Serotonin in the brain by slowing down the rate at which neurons reabsorb Serotonin after releasing the hormone. The way that our body uses Serotonin is rather simple. A neuron receives a signal to release Serotonin, and it does so, releasing it a very short distance to the next neuron, where it remains active in the space between the neurons, exerting its function.

In many patients with OCD and Depression, Serotonin is released, but it may not be released in sufficient quantities, or it may not stay active for the appropriate amount of time before it is absorbed. SSRIs can treat both of these issues by increasing the Serotonin activity in the brain.

Functions of Serotonin in Humans

Serotonin and Appetite

Many animals use Serotonin as a mechanism to convince the animals to stay in the presence of food, but in humans, Serotonin is used as an appetite inhibitor. When you smell food, this causes your brain to release Dopamine, which is why you suddenly get more hungry when you smell an appetizing meal. Serotonin, on the other hand, is released when you actually eat the food, which suppresses the release of Dopamine by the brain.

There are receptors on cells in the brain that produce Dopamine, known as 5-HT2C. These points absorb Serotonin and subsequently cause the cells to cease the production of Dopamine. In fact, there are drugs and neurological disorders which cause these receptors to deactivate, which prevents the brain from recognizing when its full, which leads to overeating. Many people that feel uncontrollable urges to eat are born without a full array of these receptors.

Serotonin and Diet

As we mentioned earlier, Serotonin is synthesized by the human body from tryptophan. Interestingly enough, simply eating food with tryptophan as an ingredient, such as turkey, does not have a subsequent effect upon Serotonin Levels. On the other hand, eating pure tryptophan does lead to an increase in Serotonin Levels.

There is a reason for this. tryptophan can cross the barrier from the blood stream to the brain, but only under certain circumstances. Tryptophan only crosses the barrier when it is isolated from other proteins that are present in food. This encourages the body to only allow tryptophan produced by its own peripheral organs to pass into the system easily, although this can be bypassed by taking pure tryptophan.

There are studies that present evidence that a high-carb low-protein diet can result in an elevation in Serotonin levels, and it does so by promoting the release of Insulin. The issue with this, however, is that if this process is sustained for a long period of time, it may lead to conditions such as Type-2 Diabetes, obesity, and increasing resistance to insulin which ultimately suppress Serotonin production.

People with more muscle actually have more Serotonin than their leaner counterparts. This is because the muscles use all amino acids except tryptophan, which, because the brain absorbs more Tryptophan when there are lower concentrations of other amino acids, increases Serotonin production.

Serotonin and the Digestive System

When we eat, food passes through the digestive system. As food passes into the intestines, it encourages the release of Serotonin by what are known as enterochromaffin cells. This encourages motility because it stimulates the contraction of the intestines. There are veins which connect to the intestines, and platelets pass this area, absorbing unused Serotonin.

Serotonin is also one of the mechanisms which cause diarrhea. If the body recognizes an irritant or potential danger in the digestive system, production of Serotonin in the digestive system increases dramatically in order to pass the offending substance(s) out of the body more quickly.

If the digestive system creates more Serotonin than the platelets can transport, this increases the concentrations of free Serotonin in the blood stream. Free Serotonin then circulates through the body and encourages nausea and vomiting. There are drugs designed to block this response, and they are generally used in order to suppress vomiting and nausea which are often symptoms of chemotherapy and radiation.

Serotonin and Social Interaction

In many animal species, one's access to food is dependent upon competition. If an animal does not display enough aggression, it may not get as much food to eat. Based upon this inter-relationship between social hierarchy and food availability, Serotonin became involved in social interaction from an evolutionary perspective.

In many animals, Serotonin encourages the animal to engage with its social peers as an alpha. On the other hand, Serotonin impacts the fight-or-flight response dependent upon the social rank of the animal. In aeta-subordinate animals, Serotonin suppresses the urge to flee, whereas in alpha animals, Serotonin encourages flight, based upon a different distribution of Serotonin receptors.

When Serotonin is used by the brain, it is usually absorbed by neurons designed to transport Serotonin. Research has shown that much of the pathology related to anxiety in humans is related to how Serotonin is distributed after it has been absorbed by these transporters.

Serotonin and Aging

There are many ways that Serotonin impacts the aging process, as well as the cognitive capabilities of the brain. In many more primitive animal species, as Serotonin levels rise, it improves certain forms of memory. Serotonin levels falls as the creature ages, which inhibits these processes, but by blocking the re-uptake of Serotonin, it is possible to bolster cognitive memory capability in spite of aging.

In human beings as well as mammals, Serotonin levels do not rise with age in the same way, but they do start to fall as people reach the late stages of the life span, which does impact cognitive capacity.

Serotonin and Bone Mineral Density

Research has shown that in human beings, Serotonin concentrations in the blood stream play a role in controlling and regulating bone mineral density. In rodent subjects, individuals that have their ability to produce Serotonin turned off in the brain but not in the digestive system experience Osteopenia. On the other hand, those that have high levels in the brain, but do not have high levels in the digestive system have elevated bone mineral density.

Human research has not been as in depth, but there is strong evidence that individuals with elevated Serotonin levels in the blood are more likely to experience Osteopenia and Osteoporosis later in life. In the future, regulating Serotonin may be a way to treat patients with health conditions related to bone metabolism.

Serotonin and Human Development

In many animals, Serotonin plays a central role in encouraging normal growth and development into adulthood. Proper Serotonin levels during childhood and adolescence ensure that the body focuses the prime amount of resources into the developing child. If there is not enough food available, or there are other similar situations which can impact health and viability during development, Serotonin levels drop, which causes the child to develop more slowly.

Serotonin also promotes the production of HGH and its related growth factors, especially IGF-1. This is one of the mechanisms which helps encourage growth during puberty, and it also increases healing capacity in the case of injury.

Serotonin and the Cardiovascular System

As we mentioned earlier, Serotonin is released by the digestive system and eventually absorbed by the platelets in the cardiovascular system. When there is damage in the arteries or veins, Serotonin encourages the healing process as it is released from the platelets after they have formed a blood clot. This released Serotonin also emits signals to the immediate area to restrict blood flow, which helps to stem bleeding.

How Does the Human Body Make Serotonin?

There are two mechanisms by which human beings and other mammalian species produce Serotonin, both of which rely on the conversion of Tryptophan into Serotonin. One form of Tryptophan known as TPH1 is converted into Serotonin by the digestive system (the enterochromaffin cells) and the pineal gland, while a second form, TPH2 is converted into Serotonin by circulatory structures attached to the digestive system (the myenteric plexis) and neurons in the brain stem (the raphe nuclei)

In lab mice, TPH1 is shown to be vitally important to heart health, and without the ability to produce TPH1, the subjects have significant issues with heart strength and circulation and have significantly increased mortality.

On the other hand, mice without the ability to produce TPH2 are fine while they are in utero, but they don't grow at the same rate as their peers after birth causing them to be much more likely to die before they have been weaned from the mother. If they survive past five weeks, they end up as healthy as their normal peers, but have significant social issues related to aggression.

How Does Serotonin Deficiency Impact Infant Health?

In the case of human beings, there is some evidence that SIDS may be the result of a malfunction in the way that the infant body processes Serotonin. In animal research, when mice were programmed to produce less Serotonin than normal, it directly led to many issues related to Sudden Infant Death Syndrome, including cardiovascular insufficiency, which increased infant mortality rates. This is because Serotonin produced by the raphe nuclei play a role in breathing as well as heartbeat.

Serotonin Depletion and Mood Disorders

Serotonin is linked to a variety of disorders associated with mood. Serotonin Deficiency is strongly linked to both Depression and Obsessive-Compulsive Disorder. Interestingly enough, Serotonin Deficiency is also a temporary condition that occurs when someone falls for another, emotionally, and is associated with OCD tendencies that occur in the early parts of many relationships.

Serotonin and Alcohol

Moderate consumption of alcohol leads directly to a state of Serotonin Depletion resulting from a reduction in the concentration of tryptophan in the blood stream. This is one of the reasons that people that drink alcohol are more likely to engage in impulsive activities, including sex, because Serotonin has a modulating effect upon both self-control and libido.

Serotonin and Your Health

As you can see, Serotonin is one of the most physiologically complex hormones produced by the human body, and affects change in a wide variety of ways. Healthy Serotonin balance is a vital part of sustaining health and wellness, both psychological and physical.

References:

Serotonin Wiki:

http://en.wikipedia.org/wiki/Serotonin

Serotonin WebMD:

http://www.webmd.com/depression/features/serotonin