May 17, 2010

Immune system and toxic chemicals; Why sick all the time

Such a good article had to repost here for my readers.  If you don't think chemicals are affecting your life please rethink that.  
Kathryn Alexander D.Th.D

To most of us immunity means the ability to resist infection and the implementation of vaccination programs to reduce the incidence of epidemics. But while we boast that we no longer have to deal with the plague or the measles, we ignore the magnitude of other health problems related to immune dysfunction such as the rise in incidence in allergies, cancers of the immune system (lymphomas, myelomas) and auto-immune disease. In fact some immunologists suggest that the “decrease in immune functions is most likely the same (50% or less) as the decrease in reproductive capacity” and correlate this with the millions of tons of toxic chemicals that have been dumped into the environment. 1 If these chemicals do cause immune suppression, and there is plenty of evidence to indicate that they do, it would certainly explain the emergence of Immune Deficiency Syndromes and the sudden appearance of strange “new” virally triggered diseases such as CFIDS (chronic fatigue immune dysfunction syndrome), CJD (Mad Cow Disease),  ICL (idiopathic CD4+ T-lymphocytopenia – a profound immune suppression without evidence of HIV infection), and the increase in allergies such as asthma which has increased world-wide at the rate of about 50% per decade - not to mention the pandemic occurrence of auto-immune diseases. 

Evidence supporting a cause-effect relationship between toxic chemicals and immune dysfunction is hard to amass, and once again we look to correlative evidence in animal and human populations. During the mid 1980s to early 1990s we witnessed disease epidemics in our marine life where colonies of dying seals, dolphins and porpoises were washed ashore. In 1987, 20,000 North Sea harbour seals were beached, and a similar fate occurred in the 1990s to dolphins in the Mediterranean.  In the case of the dolphins, mortality was blamed on a relatively weak distemper virus which had never harmed the dolphins before. On autopsy, these animals were found to have up to 400 times the normal levels of organic toxic chemicals (PCBs and dioxins) in their fat and brain tissue. These findings echoed the results of previous investigations where the magnitude of the immune suppressive effect of these chemicals (up to a 50% reduction in immune competence) was discovered. Without a functional immune system these animals were unable to resist even harmless bacteria and viruses.
The Arctic Ocean is heavily contaminated with these chemicals, and populations such as the Inuits who depend upon marine life for food, have the highest levels of PCBs found in any population. Their children have pronounced immune system deficiencies; meningitis and inner ear infections occur at rates 30 times that of American children, and they cannot be vaccinated since they do not produce any antibody response. 2

These disasters may seem remote from our experience, but other forms of immune dysfunction plague the West such as the rise in incidence in auto-immune disease. There are around 80 auto-immune diseases which include Multiple Sclerosis, Rheumatoid Arthritis, Insulin Dependent Diabetes Mellitus, Crohn’s, Ulcerative Colitis, Grave’s and Hashimoto’s thyroiditis and Lupus. In the US 14-22 million citizens (5-8% of the population) are affected, and although genetic susceptibility does play a role, the genetic pool does not change that radically to account for this increase, therefore we look to the involvement of environmental factors.  3

In auto-immune disease, the immune system starts to attack its own tissues. The programming of the immune system to recognise “self” occurs during the foetal phase in the thymus gland. We have two main branches of immune cells, the B cells which have the capacity to form antibodies to foreign tissue or bacteria and the T cells which then authorize the destructive phase. If your B cells form antibodies to your own tissues and the T helper cells authorize the go ahead – then we see the onset of auto-immune disease. However, a properly programmed immune system allows for such a possibility, and has a colony of T suppressor cells which can inhibit any self-attack. It is suggested that toxins may directly affect the programming of the immune system during the foetal stage leading to an imbalance in activity between the T helper and T suppressor cells. That toxins do affect the development of the immune systems has been confirmed, but no correlation as yet has been made with auto-immune disease.

However, what has been identified is that persistent viral infection can be a triggering mechanism. 4 Links have been made between the Coxsackie virus (aseptic meningitis) and IDDM; the Epstein Barr virus and the Human Herpes virus 6 with MS; Helicobacter pylori with gastric autoimmunity and Listeria and mycobacterium with Crohn’s disease. In genetically predisposed individuals, the antibody that is produced to arrest the specific pathogen may also cross-react with normal tissue. Normally, the T suppressor cells would not authorize any cross reactivity (and indeed patients may often carry these auto-antibodies for years before the disease expresses itself), but increasingly we are finding this not to be the case.

If we take the global increase in the incidence of IDDM in children. In the UK we see an annual increase of 12% and in NZ, 10%. In the US 13,000 new cases of childhood IDDM are diagnosed annually – which is greater than the annual incidence of childhood cancer. There is little information on the disease but spikes, or dramatic rises in mid 1980s in the US coincided with an outbreak of aseptic meningitis. 5 This points to cross-reactivity of the immune complex with the islet cells of the pancreas. Perhaps this may explain why vaccinations may be implicated in the onset of auto-immune disease. Essentially, immune dysfunction means an inappropriate response to antigens (whether they be bacteria or viruses, pollens, foods or chemicals) which is harmful to the host.

Interestingly 80% of people with autoimmune disease are female, so attention is beginning to focus on the role of oestrogen. Declining oestrogen levels at the menopause are associated with the onset of auto-immune disease in predisposed women. In younger women presenting with an autoimmune disease, symptoms are alleviated during pregnancy. This indicates a protective role for oestrogen. 6  Although it is almost impossible to prove a cause-effect relationship between the endocrine disruptive chemicals and immune dysfunction, we do know that the reproductive hormones modulate the immune system (they can turn it on, or tone it down) and that environmental oestrogens have deleterious effects on natural oestrogen production, its activity and its metabolism (see previous articles on chemicals and fertility and hormone sensitive cancers -issues?). Perhaps we are not so far off proving the scientific link between chemicals and immune dysfunction. 

I have only covered in brief some of the major trends in immune dysfunction.  Dr. Robert Repetto, in his report “Pesticides and the Immune System” indicates that greatest risk from pesticides may well lie in the impairment of human and animal immune systems. His report gives a comprehensive overview on pesticides and immune dysfunction referencing many epidemiological studies. 7 

What can we do? Again my message is the same – we need to limit our exposure to these chemicals and communities nee to start to tackle these problems locally. Pollution spreads, it is not containable, therefore the more concerted our effort, the greater our protection.

1. “The immune incompetence theory of disease.”
2. “Pesticides and the Immune system: Overview”
3. “When the Immune system goes on the attack”    
4 ibid
5 “Prevalence and incidence of Insulin-Dependent Diabetes.”
6. “The gender gap in autoimmune disease”
7. “Pesticides and the Immune system: Overview”

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