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January 2006, Vol. 16, No. 1
Table of Contents
CBP® Non-Profit Matches Dr. Bill Harris' $25,000 Research Grant • Counter Point Round III • Dr Deed Harrison is the Most Published Chiropractor in the Index Medicus • Flawed Thinking • It's Don's Opinion • JCCA Publishes CBP® Structural Rehab Protocol • More Studies to Confirm the Validity and Reliability of PosturePrint™ • Thriving in the New Health Care Marketplace • Organic Chiropractic • Patient Education • Point Round III • The Purpose Driven Practice • Radiation Hormesis • Research Corner • Subluxation Update • System Failure • Ten New Year's Resolutions for Your Practice • Chiropractic: A Useful Component of Traumatic Brain Injury Rehabiitation • Triano is a Chiropractic Pariah •
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Radiation Hormesis:
Low Doses Stimulate the Immune System and Do Not Cause Cancer - THEY PREVENT IT!
by Paul A. Oakley, MSc, DC
Perhaps surprising to hear for the first time, we’ve recently discovered that low dose radiation exposure (such as that given from x-rays) not only does NOT cause cancer, but probably helps to prevent it! That is correct, low doses of radiation exposure actually stimulate the immune system to work better, and in turn, boosts body function and health.1
In response to several outrageous comments made by chiropractic radiologists (DACBRs) following Dr. Jason Haas’ platform presentation at last year’s RAC conference (please see AJCC, April, 2005),2 I spearheaded a review of the literature project to determine the actual risk associated with radiation exposure given by x-ray use. Since Dr. Jason Haas and the CBP® research team was accused by Dr. Cynthia Peterson (CMCC) of giving the subjects in the study future leukemia and breast cancer, I thought that perhaps the use of x-ray for research purposes may be alarmingly dangerous. Our attempt was to quantify how much radiation it would take to give our patients cancer, or to project how many patients during our careers, we would actually give cancer to, as a side-effect of treating them.
As it turns out, RADIATION RISK FROM DIAGNOSTIC X-RAYS ARE NOT KNOWN BUT ONLY PROJECTED FROM AN ASSUMED LINEAR MODEL. This model is called the ‘Linear-No Threshold’ (LNT) model. This LNT model comes from estimating the risks at lower doses of radiation, in the absence of data, by extrapolating in a linear fashion, from large doses of radiation from atomic bombs dropped on Japan in the 1940s (see Figure 1). Today the LNT model is used for any known carcinogen for any exposure level assuming any exposure, regardless of how small, to claim an induced cancer.3
Since the 1950s, the LNT model has been adopted as the method used to set limits of radiation exposure by all official and government associations. The use of the LNT model includes the recent 2005 report by the USA National Research Council.4 This report states: “there will be some risk, even at low doses (100 mSv or less), although the risk is small.” In fact, assuming the LNT model, any exposure above a ‘zero dose’ theoretically increases the risk of getting cancer — despite the fact that it would be impossible to get through even one day of our lives without receiving any radiation exposure (i.e. since sources are ubiquitous: cosmic, cosmogenic, air, terrestrial, buildings, food and drink, medicine, industry, fallout, smoking, and even endogenous - that is, our own bodies!).1
The question of the day is this: Is the LNT model valid? More specifically, is the LNT model valid at predicting the health risks from diagnostic x-rays? The best available epidemiological evidence suggests NO! The evidence suggests radiation exposure has a hormetic pattern for its effects on the human body (curved pattern in Figure 1). That is, health benefits are seen at lower levels of radiation exposure (i.e. a few hundred cervical x-rays) with the expected negative health effects including cancer at very large doses (i.e. over 1 million cervical x-rays!).
The fact is diagnostic radiography provides about 1-2mSv. The data used to extrapolate to the zero dose assuming the LNT model, is primarily the Japanese data at exposure rates of more than 250mSv. It is interesting to note that even according to the Health Physics Society (1996), risks of health effects below 100mSv (that is, 50 to 100 times the exposure levels from x-rays) health risks are nonexistent (too small to observe).5 This equates to 455 Cervical series or 77 Lumbar series!6
In a commentary in the December edition of the Journal of the Canadian Chiropractic Association (2005; 49(4):262-267.),7 we review many fascinating studies that are in direct contradiction to the LNT model. This information remains largely unknown partly because it has been published after the 1950s, the time when the model became adopted by all major organizations as the method to use to set radiation limits. The fact is, however, analyses of the best available evidence suggest “humans need a level of radiation above natural background in most areas of the world”8 and that low levels of radiation actually prevent cancer, not cause it.!1,9-11
In a recent review, Kant et al. state: “Through various studies, it is established that whole body exposure to low-level ionizing radiation decreases overall cancer incidence (the most important long-term somatic effect of radiation exposure)...whole body exposure to (ionizing radiation) reduces cancer mortality rates when compared with control populations in both experimental animals and humans.”9 In 1991, Luckey published the most thorough review at the time with over 1,000 references and determined that optimal radiation exposures (i.e. 200 times current safety limits) unequivocally enhance health levels (see Table 1). The evidence that we review in two separate articles in the Journal of the Canadian Chiropractic Association’s Dec. 2005 issue suggests that radiation is such an important element for health that some recommend its supplementation to prevent cancer.11,12 For curiosity sake, the supplemental dose recommendations are equivalent to about 18 cervical series per month or three lumbar series per month!
It’s time for DACBRs and others with ‘radiation phobia’ to learn the other side of the story. If Dr. Fred Barge taught me one thing, it’s that ‘the majority is usually wrong’ — of course, this has been shown throughout modern history, i.e. blood-letting, hormone-replacement therapy etc. This is also true within the chiropractic profession on several issues, one being the risks presumably thought to be associated with routine use of radiography in practice. For a more thorough review of the scientific evidence against the propagated LNT model and the evidence for health enhancement, see our articles in the Dec. 2005 issue of the Journal of the Canadian Chiropractic Association, go to: www.jcca-online.org.
1. Luckey TD. Radiation hormesis. Boston:Boca Raton: CRC Press, 1991.
2. Haas JW. DACBRs cause professional embarrassment at RAC. American Journal of Clinical Chiropractic, April 2005: p.1 & 6.
3. Bolus NE. Basic review of radiation and terminology. J Nucl Med Technol 2001;29:67-73.
4. Committee to assess health risks from exposure to low levels of ionizing radiation. Health risks from exposure to low levels of ionizing radiation: BEIR VII Phase 2. National Research Council. Washington DC: National Academies Press, 2005.
5. Mossman, K. L., Goldman, M., Masse, F., and et al. Radiation risk in perspective: Health Physics Society position statement. 1996. Idaho state University Dept of Physics and Health Physics Web site: (www.physics.isu/radinf/hprisk.htm)
6. Oakley PA, Harrison DD, Harrison DE, Haas JW. Evidence-Based Protocol for Structural Rehabilitation of the Spine and Posture: Review of Clinical Biomechanics of Posture (CBP®) Publications. J Canadian Chiro Assoc 2005;49(4):268-294.
(www.jcca-online.org)
7. Oakley PA, Harrison DD, Harrison DE, Haas JW. On ‘phantom risks’ associated with diagnostic ionizing radiation: evidence in support of revising radiography standards and regulations in chiropractic. J Can Chiropr Asso. 2005; 49(4):262-267. (www.jcca-online.org)
8. Cameron JR. Radiation increased the longevity of British radiologists. Br J Radiol 2002;75:637-640.
9. Kant K, Chauhan RP, Sharma GS, Chakarvarti SK. Hormesis in humans exposed to low-level ionising radiation. Int J Low Rad 2003;1:76-87.
10. Luckey TD. Radiation hormesis in cancer mortality. Chinese Medical Journal 1994; 107(8): 627-630.
11. Luckey TD. Nurture with ionizing radiation: A provocative hypothesis. Nutrition and Cancer 1999; 34(1):1-11.
12. Chen W.L. Luan Y.C. Shieh M.C. et al. Is chronic radiation an effective prophylaxis against cancer? J Am Phys Surg 2004; 9(1):6-10.
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