Submitted by Dr. Robert D. Lucas
There was an article entitled “Red Meats Cause Cancer” in the Advocate of Sunday, 1ist.November 2015, by Mr. R.E. Guyson Mayers. Mayers was guilty of disseminating incorrect information,
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which displayed his gross ignorance of the subject as I will show and I will explain some facets of food risk and meat processing.
The World Health Organization’s (WHO) advisory linked the excessive use of processed red meats with an eighteen percent increase above the basal level, in the risk of colorectal cancer in humans. The advisory went on to state that that there was no link between the consumption of red meats and cancer, but posited the opinion that red meats probably caused cancer, which I find to be rather unscientific on WHO’s behalf. The advisory concluded by stating that, there was no problem, if the consumer restricted intake to one hot dog or 50g (about 2 oz.) of processed red meats daily. Mayers is referred to the British Broadcasting Corporation’s (BBC’s) Programme “ More or Less” of 5th.November 2015 and to the Independent, Uk newspaper of the 28th. And 30th. October, 2015, to articles entitled “Cancer-so how dangerous is a bacon sandwich?” By Kashmira Gander and “WHO insists it is not telling people to stop eating bacon after cancer report” by Lizzie Deardens respectively. As a matter of fact, the WHO’s advisory is only a rehash of the advisory it published in 2002, as it admitted. There was no out-cry then.
Paracelus, the founder of the modern discipline of toxicology in the sixteenth century stated: “All substances are poisons; there is none which is not a poison. The right dose differentiates between a remedy and a poison” (Institute of Food Technologists’ Scientific Status Summary: “Assessing, Managing, And Communicating Chemical Food Risk” IFT Expert Panel on Food Safety and Nutrition, 1997.pp85-92). The salient factor here is the dosage consumed. Before I deal with dosage and risk analysis, it is necessary to give some back ground on meat curing. The pigment in meat is called myoglobin. In the presence of nitrite and heat, compounds called amines which are derivatives of amino acids found in proteins combine to give rise to intermediary compounds called nitrosamines. Nitrosamines are precursor compounds which can result in cancer development. Nitrites are used to give cured meats their pink colour, cured meat flavour and to inhibit the formation of the neurotoxin formed by the bacterium C. botulinum, which causes food intoxication and death; the mortality rates from this toxin are very high. To inhibit the formation of nitrosamines ascorbic or its mirror image erthorbic acids are used in cured meats formulation. The formation of nitrosamines is favoured in the presence of fat and high temperatures and streaky bacon is an ideal product. It is for this reason that nitrite is restricted to 100ppm in bacon end products.. All of these adverse effects have been known since the 1950’s and several attempts have been made to find replacements for nitrite to no avail. Mayers is referred to the article by IFT Expert Panel “Nitrites, Nitrates, and Nitrosamines in Food- a Dilemma” Journal of Food Science. 1972:37:89-92. Since the 1950’s, in animal model systems, very high rates of nitrosamines have been fed to test animals, which exceed cumulative amount of nitrites/nitrosamines ingested in humans in a normal life-span spent consuming processed red meats by several order of magnitude.
Compounds which are suspected to be carcinogenic are assumed to cause cancer at any level of ingestion. Whereas, non-carcinogenic food additives in model systems are assumed to have a threshold level, below which no adverse effects are observed; this is called the no observable effect level (NOEL). The point immediately above the threshold level is called the lowest observable effect level (LOEL). These NOEL and LOEL are used to establish guideline for the use of non-carcinogenic food additives. To rationalize this anomaly in the case of suspected carcinogens, risk analysis is done. .I will illustrate what I am talking about with practical examples. Chlorine is used to ensure the safety of potable water at about 200ppm, depending on the amount of organic matter present in the water. At this level there is no problem. If used at 1000ppm, chlorine is carcinogenic. Regulatory bodies therefore have a decision to make. Not to use chlorine can result in outbreaks of cholera, typhoid, amoebic dysentery and other microbial diseases. The cost-benefits have to be weighed, water borne disease or the risk of cancer. Similarly with use of nitrites in processed red meats. A trade–off has to be made. In 2002, there was hue and cry about presence of acrylamide in bread. Acrylamide is formed by some starches when heated. It is highly toxic and carcinogenic. People are still eating bread; acrylamide is still present in bread.
I want to disabuse Mayers of the idea that there is such a thing as a hundred percent safe and risk free food. The food industry and regulatory bodies do their utmost to minimize the risks. I will illustrate with an example what I am talking about. The Jack-in-the Box Food chain in the USA. Customers suffered an out-break of E. coli food poisoning from consuming the chain’s hamburgers. The chain cooked the hamburgers to the recommended United States Department of Agriculture (USDA) internal temperature. However, the E.coli had mutated and required a higher internal to destroy it. Some people died.
Mayers also alluded to the use ethyl and methyl mercury and asbestos. In the case of asbestos, he is referred to an erudite article published in the local press by Professor Henry Fraser, sometime ago. As for mercury, the methyl mercury bio-accumulates in the body. The ethyl form is use in small quantities and in any event, how manty vaccines doe one get in a life time? By the way, tuna and albacore red flesh, are people going to stop eating tuna or albacore?
Robert D. Lucas, PH.D. , CFS
Certified Food Scientist.
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