Dr Charles Forsyth

Integrated Medicine

 
 

DNA Adducts & Cancer & Environmental Pollutants


DNA adducts are chemicals that are covalently bound to the genomic DNA. The source of the chemicals can be either exogenous (xenobiotic) or endogenous (including metabolites of xenobiotics).


The effect of an adduct depends on it’s location on DNA:

  1. An adduct on a gene will usually reduces (down-regulates) or blocks that gene’s expression. 

  2. An adduct near (eg. on the promotor region of) a gene may lead to over-expression of that gene.

  3. An adduct may block DNA repair mechanisms.

  4. An adduct may interfere with the current methylation pattern (epigenetic coding).


The methylation pattern on DNA acts as a template for gene expression, blocking or allowing the expression of different genes along the DNA strand.  Environmental challenges, lifestyle factors and numerous metabolic feedback mechanisms influence DNA methylation. These “epigenetic” mechanisms control gene expression in a way that can be passed on to “daughter” cells without changes to the DNA sequence - even when the original cause is no longer present - so if an adduct caused the change in methylation pattern, the genetic expression continues as if the adduct was still there.


It has been known for decades that a very wide range of chemical substances (carcinogens) can play a major role in causing or contributing to many forms of cancer.  One important way that carcinogens have their effect is through DNA adducts - an adduct next to an oncogene (cancer predisposing gene) will tend to activate it, while an adduct on an anti-tumour gene will tend to block it - in both situations there will be increased predisposition to cancer.


DNA adducts and epigenetic mechanisms are now considered to be a major factors predisposing to many chronic disease processes.  DNA adduct formation is dependent on:

  1. 1)Exposure to, absorption of, retention of and distribution of toxic substances, including penetration through cellular membranes and into the cell nucleus where the DNA resides, and

  2. 2)The presence of other potentially toxic compounds that increase absorption, distribution and penetration of the toxin(s) in question - this particularly applies to ‘penetration enhancers’ - mainly synthetic detergents (surfactants) including Cetrimide (CTAB), Octoxynol, Polyethyl alcohols, Polyethyl ethers, Polyoxyethylene esters, Polyoxyethyl ethers, Polysorbates.

  3. 3)Nutritional status, which in turn influences toxin absorption, retention, etc, antioxidant status, DNA protection and repair, detoxification pathways, etc. - this is especially true of zinc which, amongst it’s other functions, has multiple roles relating to DNA.


Until recently, there has been no test readily available to clinicians (anywhere in the world) to detect and measure the presence of DNA adducts in humans.  Dr John McLaren Howard of Acumen (formerly head biochemist at Biolab) has developed this test that is capable of identifying and measuring a great many substances that can form DNA adducts and much of the time also identify which the genes are affected.


Indications for this test include:

  1. Anyone who has ever had cancer, including unusual types of cancer

  2. Anyone who has predisposing factors to cancer, eg. a family history of cancer.

  3. Anyone who has had known or suspected exposure to carcinogenic substances - past and present.

  4. Anyone who has smoked tobacco or spent a lot of time in smokey atmospheres (passive smoking) - however long ago.  We have patients in their 60’s who have never smoked, and never been passive smokers, except as children living with smoking parents - and they still have high levels of nitrosamine DNA adducts (and have never had any other exposure).

  5. Anyone who has had or suspects exposure to environmental pollutants (incl. pesticides) at work or at home.

  6. Anyone with unusual, not easily explained symptoms.

  7. Anyone who has been found to have toxins bound to their mitochondria.

  8. Anyone who wants to identify factors that may be undermining their health - factors that they can take positive action about.


See: www.cancerpreventionsociety.org for more information regarding environmental pollutants and cancer.


For more information see my information sheet: Downloads

DNA Adduct Investigations

   INVESTIGATIONS:    Nutritional     Gastrointestinal     Toxins     Others      New Tests