Understanding Optimal Health, part 2
In our last blog we discussed the importance of nutrition for health and how cellular health and regeneration depend heavily on nutrients and metabolism. In today’s blog we’ll talk about nutrient absorption, how the GI system works, how the brain influences our gastrointestinal system for good or for bad, and the effects of chronic stress on the immune and endocrine systems.
Let’s start with a brief definition of what the digestive system is. It’s a group of organs and networks working together to break down food into nutrients to feed the entire body. It begins with the gastrointestinal tract (or GI for short). The GI is an open canal that begins in the mouth, passing through the esophagus, to the stomach and into the intestines. It requires specific enzymes, cellular chemicals, and muscle reflexes in order to move food along and digest it. Some of these enzymes are produced by the pancreas while important chemicals that break down fat are produced by the liver. Any disorder in these parts affects digestion. Any variations in brain equilibrium affects the function of the digestive system.
Nutrient absorption takes place in the intestines, most absorption occurring in the small intestine. The intestines are a 23 foot long tube that contains specialized cells that absorb diluted components of nutrients from our food. In the intestines are colonies of bacteria. About 3 pounds worth of bacteria live there, composed of hundreds of different types of bacteria. Each type lives in a specific region, however, there are about 10 times more bacteria living here than we have cells in our bodies. Although we tend to think of bacteria as harmful, these particular bacteria are a huge benefit to us and help us stay healthy.
Good bacteria feed off of what we eat and in return they produce enzymes and other chemicals that aid in digestion and prevent us from absorbing harmful chemicals. Additionally they help keep harmful bacteria out of the intestines and regulate intestinal inflammation. These bacteria also participate in certain hormone regulation. An important one being Ghrelin, which makes us feel hungry. If this hormone is unregulated then we feel hungry even if we don’t need food.
These gut bacteria can also influence the amount of cortisol (a stress hormone) in the body affecting the availability of Gaba. This is done as certain chemicals which are produced by lactobacillus (a type of bacteria) are received by vagus nerves causing signals to be sent to the brain, monitoring stress levels and suppressing cortisol release.
These bacterial colonies also communicate with immune cells on the other side of the intestines. They send messages of environmental conditions, toxin levels, and report any invasive bacteria. By doing so the immune cells can mobilize and take action against potential threats.
Keep in mind that these bacteria eat what we eat and are sensitive to synthetic products. Consuming such products, especially regularly, affects their function and can change the Ph level in the GI. This causes them to grow sick or die. A decrease in bacteria population in the intestines has huge negative affects on our health.
Now let’s take a look at stress. The effects of stress on the digestive system is well known to the medical community. Disruption or changes in this system affects the production of digestive juices in the stomach and other enzymes. Additionally the mechanical parts of this process are affected, leading to inflammation, constipation, or chronic diarrhea. Hormonal changes due to stress create problems in the production of other hormones and chemicals involved in digestion, such as gastrin and CCK. Even leptin (responsible for making us feel full) is altered during stressful episodes. This leads to chronic illnesses in our digestive system.
How does stress do this? Well we know that a great number of nerve branches from the brain communicate with the intestines. To aid in digestion a chemical, acetylcholine, is released to help intestines move or release other enzymes. However, this only occurs if we are relaxed. If we’re stressed, on the other hand, the nerves release another chemical which cuts blood supply to the intestines to decrease enzyme production and motility. Acute stress also produces inflammation, causing a reduction of mucus lining in the stomach. Another problem with stress is serotonin production, which regulates muscle contractions. Stress or depression reduces this production, causing colon inflammation.
Now let’s return to the immune cells briefly mentioned earlier. The role of these troops in to kill any pathogen that enters the body, destroy unrepairable sick cells (including cancerous cells), and remove dead or damaged tissues and cells. These immune cells are created in our bones, spleen, and thymus. Chronic stress or other damages to the immune system create two potential problems: Immune deficiency and immune over activity.
When we have a deficient immune system it means either there aren’t enough immune cells being produced or the immune cells produced are created incorrectly. If they aren’t created correctly the immune cells patrol the body, but might not recognize invaders, letting them live and cause damage. Immune over activity is the cause of autoimmune problems such as rheumatoid arthritis, lupus, allergies, psoriasis, and dozens of other conditions. This is when immune cells view healthy cells and tissues as a threat and attack and kill them. Cardiovascular disease is also caused by an inflammatory response and an overactive immune system and excess epinephrine dump into the bloodstream by constant stress.
Everything in the body is regulated. However, the immune system needs to be tightly regulated to ensure health. The nervous system, hypothalamus and pituitary gland projections are involved in controlling both response and inhibition of the immune system. However, these same parts are responsible for activating and shutting down the stress mechanism. Any over activity of the stress mechanism affects immune response and consequently damages the body unless there is a change in our lifestyle.
Our last topic for today is the endocrine (hormonal) system. Hormonal response is affected by stress. Cortisol, norepinephrine, and epinephrine are the main players here and are activated by excitatory and inhibitory hormones to ensure that stress is under control. When we are chronically stressed more cortisol and adrenaline are released with little amount of inhibitor hormones being present to regulate the stress. Excess cortisol is a sign that the stress mechanism is consistently being activated. Overproduction of this hormone also affects the regulation of other hormones, altering endocrine regulation. This creates problems with libido, metabolism, weight, energy, memory and retention, and a cascade of other problems in the body.
In our next blog we’ll discuss cellular damage and inflammation, and how chronic stress affects telomeres in chromosomes and early cellular aging.