Every day our immune systems are subjected to tremendous stresses. These stresses come from both external and internal sources.
The external stressors include things like pathogens, toxins, poisons and radiation. Pathogens are infectious agents such as viruses, bacteria or fungus that cause disease in its animal or plant host. Toxins, according to several sources, are defined as poisonous substances produced within living cells or organisms. This definition thus excludes man-made substances created by artificial processes and instead the term toxicant or toxics are used to refer to these latter substances.
However, as often happens, the word toxin has come to be commonly used to describe any substance that is capable of causing disease on contact or absorption by the body. As well, pathogens have also been categorized as toxins by some. For simplicity purposes this document will use the word toxin as a catch-all term.
One source has classified these toxins into the following three categories.
1. Exogenous toxins which come from external sources. These fall into four main categories.
- Environmental toxins: Included in this category are industrial pollution from car fumes, factory pollution (lead, mercury, etc.), combustion pollutants, asbestos, pesticides and insecticides used on fruit and vegetables, etc.
- Household toxins which include seemingly innocent culprits such carpets and rugs which often contain stain-repellent or fire-retardant chemicals. Also included are the VOCs (Volatile Organic Chemicals) such as organic solvents, some paint additives, aerosol spray propellants, fuels (gasoline, kerosene, etc.)
- Food toxins which include growth hormones, chemical fertilizers, pesticides, antibiotics, and mercury, etc.
- Lifestyle toxins which are caused by smoking, drinking, over-the-counter, prescription, and illegal drugs, food additives and colorants, amalgam dental filings, etc.
We inhale and ingest natural and synthetic toxins every day of our lives and can’t possibly avoid them, especially in our technological times, our congested, polluted cities and with our engineered food supplies.
2. Endogenous toxins which come from viral or bacterial infections.
3. Autogenous toxins which are created by the body itself due to its own metabolism. Cells derive their energy from the continuous consumption (oxidation) of fuel (nutrients and oxygen). However, this essential oxidation process produces harmful waste products called free-radicals or oxyradicals.
Such toxins are circulating through our bodies continuously and damage individual cells and organs. The main human physiological defense against the above “invaders” is the immune system.
Reactive Oxygen Species (ROS)
In general, the effect of the above toxins is to generate something called reactive oxygen species (ROS) which are chemically reactive molecules containing oxygen.
Most reactive oxygen species come from the autogenous sources as by-products of normal and essential metabolic reactions, such as energy generation from mitochondria or the detoxification reactions involving the liver. If not neutralized, these reactive oxygen species can cause damage to cells or disrupt DNA patterns leading to cancer. Note that this oxidation process is exactly the same one that causes metal to rust, apples to rot or butter to turn rancid. In humans, the accumulated damage from such oxidation contributes to natural aging.
However, it must be noted that, reactive oxygen species are beneficial, as they are used by the immune system as a way to attack and kill pathogens. The trick, as with most things, is to keep things in balance.
Oxidative Stress
The term oxidative stress is used to describe the imbalance that results between the production and manifestation of reactive oxygen species and a biological system’s ability to readily detoxify the reactive intermediates or to repair the resulting damage. This damage can affect a specific molecule or the entire organism.
The level of oxidative stress is determined by the balance between the rate at which oxidative damage is induced (input) and the rate at which it is efficiently repaired and removed. The rate at which damage is caused is determined by how fast the reactive oxygen species are generated and then inactivated by endogenous defense agents called antioxidants. The rate at which damage is removed is dependent on the level of repair enzymes.
The determinants of oxidative stress are an individual’s unique hereditary factors, as well as his/her environment and characteristic lifestyle
One of the things that assists in the control of reactive oxygen species is antioxidants. Some commonly known antioxidants are: beta-carotene, lycopene, vitamins A, C and E. However, the master antioxidant is Glutathione. Another menu tab discusses Glutathione and for even more detailed information please refer to the excellent book Glutathione, Your Key to Health by Dr. Jimmy Gutman. It is very informative read.