Cancer Risks Of CT ScansDecember 2015
By Andrea Levy
Every year, Americans are exposed to potentially unsafe levels of DNA-altering radiation through medical imaging such as CT scans.
An astonishing 72 million CT scans are performed annually in the United States, which is about one scan for every four people in the country each year.1
Why is this so troubling? Because the radiation in that CT scan can increase your risk of cancer.
National Cancer Institute researchers now estimate that those 72 million CT scans could account for roughly 29,000 future cancer cases each year!1 Another way of looking at this figure is that for roughly every 400 to 2,000 routine chest CT scans, one new case of cancer occurs.1
And, by some estimates, up to 44% of CT scans done in this country each year are medically unnecessary.2
Despite these dangers, modern imaging techniques have been a tremendous boon to health care, allowing physicians to spot cancers, fractures, aneurysms, abscesses, and other risks that would otherwise go undetected.
But what if there was a way to get the benefits of a CT scan while reducing your risk of DNA mutation?
Three natural compounds have been shown to have properties that may help counteract the most dangerous consequences of radiation exposure.
If your doctor orders an X-ray or CT scan, taking these compounds at least five days prior may help protect against cellular damage inflicted by the ionizing radiation.
In addition, regular consumption of blueberries or blueberry extract enhances DNA repair, which may help reverse some of the genetic damage inflicted by ionizing radiation.
CT Scans Boost Cancer Risk
After years of overlooking the potential risks of medical imaging, mainstream physicians are finally beginning to acknowledge the dangers of these radiation-based diagnostic tools.
In 2013, a scientific consensus was reached that even just one CT scan in childhood is linked to the risk of developing future cancers. Of course, cancer risk estimates for individuals must also include other criteria like specifics of exposure, age at exposure, and absorbed dose to certain tissues.3
This consensus was likely triggered by a deeply disturbing 2013 study published in the prestigious British Medical Journal (BMJ).4
The researchers behind that study followed approximately11 million individuals from birth in the 1980s into young adulthood, identifying over 680,000 who had at least one CT scan during that period. They compared the cancer rate in this extremely large group of patients with an equally large, matched group who were never exposed to a CT scan.
The results were alarming.
The study found that those who had undergone CT scans in their childhood had a 24% increased risk for developing any cancer, compared with those who didn’t have scans.4 They also found that the more scans a person had, the greater the risk of developing cancer.
The risk persisted for years after the original scan was completed, producing cancer risks, compared with unexposed individuals, which were:4
- 35% higher in the first four years following exposure
- 25% higher at five to nine years
- 14% higher at 10 to 14 years
Even 15 or more years following the first exposure to this level of ionizing radiation, cancer risks remained stubbornly elevated by 24%.
Virtually every kind of cancer was documented to occur in excess in the CT-exposed group, including solid tumors (digestive organs, skin, ovary/uterus, urinary tract, brain, and thyroid), leukemia (blood cancer), lymphomas, and other cancers.4
Let’s take a quick look now at exactly how the radiation in CT scans (and other X-ray-based technologies) raises your cancer risk and threatens your longevity. Understanding this will help you and your doctor make a more rational decision as to whether a particular CT scan is scientifically warranted.
How Ionizing Radiation Causes Cancer And Other Deadly Threats
For all the potential good they can do, CT scans expose us to surprisingly high levels of ionizing radiation. On a cellular level, ionizing radiation can strip electrons from the atoms that make up our tissues, producing energetic chemical ions that damage tissue and impose potent genetic stresses.
One of the most dangerous outcomes of exposure to ionizing radiation is damage to the DNA contained in the nucleus of the cells in your body.5 Damaged DNA is an open invitation to cancer development. The problem that damaged DNA presents is that it removes the effective controls our bodies use to regulate the cell reproductive cycle and keep cell growth and replication in check.6
Ionizing radiation’s effects on tissues are both immediate and long lasting. When human tissue is irradiated, a number of DNA-breaking compounds form. Together these are known as “clastogenic factors.”7-9 Most clastogenic factors that form in living tissue are associated with reactive oxygen species whose unpaired electrons actively react with DNA molecules, inducing breaks in DNA strands that can lead to cancer.10-12
Unfortunately, cancer-inducing clastogenic factors have a very long life within the body. Studies show that survivors of the atomic bomb attacks in Japan continued to have such factors detectable in their blood more than 30 years later.7
Ionizing radiation poses a large range of other threats to one’s health as well. It can directly impair cell functions, leading to the loss of proper tissue and organ operation as well as killing cells.13 One victim of ionizing radiation is the fat-laden cell membrane. Under the effects of ionizing radiation, membrane-bound fats undergo oxidation and form toxic breakdown products.14
Recent studies also document that X-rays and other forms of ionizing radiation activate inflammatory pathways and produce early cell death.15 And, ever since the first nuclear physicists began assembling atomic bomb components, it has been clear that ionizing radiation causes potentially lethal but silent bone marrow damage. This impairs the development of the white blood cells that protect us from infections and cancer, the red blood cells that carry oxygen to all of our tissues, and the platelets that help us stop bleeding after an injury.16,17 And bone marrow is where hematological cancers like leukemia originate.
Protection From Ionizing Radiation
Fortunately, it may be possible to derive the benefits of modern imaging techniques while obtaining some protection from the radiation exposure.
Three specific nutrients have been found to help counteract the toxic effects of ionizing radiation. They include the following:
- Lemon balm, which prevents the formation of damaging chemicals triggered by ionizing radiation,18,19
- Ginkgo biloba, which protects fragile DNA from the resulting cancer-causing damage,7,8
- Spirulina, which stimulates the immune system, particularly bone marrow, to make and maintain levels of white blood cells, whose production is impaired by ionizing radiation.20
Let’s look at each individually.
Lemon Balm Extract
Lemon balm extract is known for its ability to preserve foods, particularly meats, from oxidant stress that induces spoilage. This same mechanism helps protect against a similar form of chemical stress induced in the body by ionizing radiation.18 In fact, one particular study found that lemon balm extract has numerous protective mechanisms:
- Lemon balm can boost levels of the superoxide dismutase (SOD), an essential component of the body’s native ability to protect itself from the effects of ionizing radiation and other major chemical stresses.19
- Lemon balm defends lipid cell membranes in living organisms, as shown by a sharp reduction in the lipid peroxidation that is a measure of direct cell damage following radiation exposure.19
- Lemon balm also protects DNA, as shown by a reduction in the amount of the plasma marker 8-OH-dG, a product of oxidized DNA damage.19,21
A human study documents the benefits of lemon balm in radiation technologists, who are exposed to persistent low-level radiation during their routine work despite taking precautionary measures. For the study, the radiation technologists consumed lemon balm tea (1.5 grams/100 mL) twice daily for 30 days.19
The lemon balm tea produced a beneficial increase in the activity of natural enzyme systems that fight chemical/oxidant stress, including:
- A 71% increase in superoxide dismutase (SOD) activity,
- A 12% increase in glutathione peroxidase (GPX, another native antioxidant molecule) activity,
- A 61% increase in catalase (CAT) activity.
In addition, the lemon balm tea produced a beneficial decrease in numerous markers of cellular and DNA damage, including:
- A 31% decrease in the activity of myeloperoxidase (MPO, an indicator of fat oxidation)
- A 29% decrease in markers of lipid peroxidation (LPO), indicating cell membrane damage,
- A 10% decrease in 8-OH-dG, a marker of DNA damage.
In other words, prior to supplementation, these technologists, despite careful shielding and limitation of their exposure, were walking around with evidence of the impact of ionizing radiation in their bodies, which was reduced by lemon balm supplementation.
Ginkgo biloba is a well-known botanical capable of scavenging the reactive oxygen species that make up the bulk of clastogenic (DNA-breaking) factors produced by radiation.22 Ginkgo biloba reduces the levels of DNA strand breaks that lead directly to cancer.
Lab studies show that irradiation of whole blood from healthy volunteers produced an average of 18 abnormal chromosomes per 100 cells, which indicates very high-level clastogenic activity. However, when similar specimens were treated with ginkgo biloba extract, the number of abnormal chromosomes fell to 7.3 per 100 cells—a significant reduction of nearly 60%.8
The protective effects of ginkgo biloba extract were demonstrated in a unique, if tragic, setting: the 1986 radiation disaster at Chernobyl, in what is now Ukraine.
A 1994 study evaluated blood samples from Armenian workers involved in the initial clean-up of the nuclear reactor, finding an average of 17.9 per 100 cells with chromosomal damage, compared with just 5.7 per 100 in control samples. The same group of researchers treated 30 of those workers with ginkgo biloba extract, containing bioactive flavonoids and terpenoids, at a dose of 40 mg three times daily (total dose 120 mg per day) for a two-month period.7
At the end of the treatment period, the clastogenic (DNA-breakage-inducing) activity of the subjects’ plasma fell to control levels. The benefits persisted for at least seven months, but by one year, 33% of the workers again showed elevated clastogenic factors, demonstrating the persistency of the cancer-inducing risk of radiation damage to DNA.
A more recent study demonstrated the protective effects of ginkgo biloba extract in patients undergoing radioactive iodine treatments for Graves’ disease (an autoimmune condition involving abnormally high thyroid activity).23
Radioactive iodine therapy increased chromosomal damage in placebo patients, which peaked at 21 days. In patients supplemented with ginkgo, that early rise in chromosomal damage was followed by a rapid return towards baseline levels. This study revealed a significant increase in DNA damage in the placebo group overall. Interestingly, clastogenic factors never rose significantly above baseline in the ginkgo supplemented subjects.23
Since radioactive iodine therapy is provided as implanted material, this study demonstrates the potent radioprotective effect of ginkgo biloba extract even in the face of continuous radiation exposure within the body.
Spirulina extract enhances white blood cell production following exposure to ionizing radiation.
The bone marrow is a major site of immediate toxicity from ionizing radiation. Those exposed to very high doses of radiation often end up with fatal, overwhelming infections.20,24 Spirulina extract promotes the production of bone marrow-stimulating growth factors such as granulocyte macrophage colony-stimulating factor (GM-CSF).20,24
Another way spirulina helps protect the immune system is by increasing the production of antibodies.25 Antibodies are complex proteins that bind to invading organisms, and flag them for destruction.26 In a study of mice exposed to gamma-irradiation, spirulina polysaccharides containing a molecule called C-phycocyanin stimulated the recovery of white blood cells and bone marrow cell counts suppressed by the radiation exposure.27 In addition, radiation-induced anemia was also suppressed.
These effects translate directly into humans, as shown by a study using lymphocytes (white blood immune system cells) from nuclear power plant workers, which showed that pretreatment of the cells with C-phycocyanin from spirulina stimulated the cells’ natural antioxidant systems, protecting them from destruction.28
In a compelling study of youngsters exposed to radioactive fallout from the Chernobyl nuclear plant explosion, a daily 4 gram dose of spirulina (containing the active C-phycocyanin) for 21 days produced marked increases in the white and red blood cell counts that had been suppressed by the radiation.29 Additionally, elevated levels of inflammatory eosinophils were restored back into the normal range, and anemia, as defined by low hemoglobin levels, was also corrected.
The use of medical imaging technology, especially CT scans, enables doctors to noninvasively see injuries and diseases deep inside our bodies. But that same technology brings with it a serious threat: ionizing radiation.
A recent study showed a single CT scan in youth can increase one’s long-term risk for subsequent cancer by 24%.
Fortunately, specific nutrients with complementary actions may help provide protection against radiation ahead of time. Lemon balm extract prevents formation of dangerous reactive chemicals formed by ionizing radiation exposure, ginkgo biloba extract protects DNA from cancer-causing damage, and spirulina extract supports bone marrow and its production of vital blood cells.
If you need to undergo a CT scan or other potent source of ionizing radiation, start supplementing with these three protective ingredients one to three times daily for five days prior to the scan and for a minimum of five days afterwards. They are now available in a combination formula for consumer convenience.
In addition, regular consumption of blueberries or blueberry extract markedly enhances DNA repair, which can help protect damaged cells from undergoing deadly mutations.
If you have any questions on the scientific content of this article, please call a Life Extension® Health Advisor at 1-866-864-3027.
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- Canadian Agency for Drugs and Technologies in Health. Radiation Emissions from Computed Tomography: A Review of the Risk of Cancer and Guidelines. Ottawa ON: 2014.
- Westra SJ. The communication of the radiation risk from CT in relation to its clinical benefit in the era of personalized medicine: part 1: the radiation risk from CT. Pediatr Radiol. 2014 Oct;44 Suppl 3:515-8.
- Mathews JD, Forsythe AV, Brady Z, et al. Cancer risk in 680,000 people exposed to computed tomography scans in childhood or adolescence: data linkage study of 11 million Australians. BMJ. 2013;346:f2360.
- Yu H. Typical cell signaling response to ionizing radiation: DNA damage and extranuclear damage. Chin J Cancer Res. Jun 2012;24(2):83-9.
- Broustas CG, Lieberman HB. DNA damage response genes and the development of cancer metastasis. Radiat Res. 2014 Feb;181(2):111-30.
- Emerit I, Oganesian N, Sarkisian T, et al. Clastogenic factors in the plasma of Chernobyl accident recovery workers: anticlastogenic effect of Ginkgo biloba extract. Radiat Res. 1995 Nov;144(2):198-205.
- Emerit I, Arutyunyan R, Oganesian N, et al. Radiation-induced clastogenic factors: anticlastogenic effect of Ginkgo biloba extract. Free Radic Biol Med. 1995 Jun;18(6):985-91.
- Lindholm C, Acheva A, Salomaa S. Clastogenic plasma factors: a short overview. Radiat Environ Bioph. 2010 May;49(2):133-8.
- Emerit I. Clastogenic factors as potential biomarkers of increased superoxide production. Biomark Insights. 2007;2:429-38.
- Morgan WF. Is there a common mechanism underlying genomic instability, bystander effects and other nontargeted effects of exposure to ionizing radiation? Oncogene. 2003 Oct 13;22(45):7094-9.
- Riklis E, Emerit I, Setlow RB. New approaches to biochemical radioprotection: antioxidants and DNA repair enhancement. Adv Space Res. 1996;18(1-2):51-4.
- Kobashigawa S, Kashino G, Suzuki K, Yamashita S, Mori H. Ionizing radiation-induced cell death is partly caused by increase of mitochondrial reactive oxygen species in normal human fibroblast cells. Radiat Res. 2015 Apr;183(4):455-64.
- Agrawal A, Kale RK. Radiation induced peroxidative damage: mechanism and significance. Indian J Exp Biol. 2001 Apr;39(4):291-309.
- Luzhna L, Kovalchuk O. Low dose irradiation profoundly affects transcriptome and microRNAme in rat mammary gland tissues. Oncoscience. 2014;1(11):751-62.
- Green DE, Rubin CT. Consequences of irradiation on bone and marrow phenotypes, and its relation to disruption of hematopoietic precursors. Bone. 2014 Jun;63:87-94.
- Heylmann D, Rodel F, Kindler T, Kaina B. Radiation sensitivity of human and murine peripheral blood lymphocytes, stem and progenitor cells. Biochim Biophys Acta. 2014 Aug;1846(1):121-9.
- Lara MS, Gutierrez JI, Timon M, Andres AI. Evaluation of two natural extracts (Rosmarinus officinalis L. and Melissa officinalis L.) as antioxidants in cooked pork patties packed in MAP. Meat Sci. 2011 Jul;88(3):481-8.
- Zeraatpishe A, Oryan S, Bagheri MH, et al. Effects of Melissa officinalis L. on oxidative status and DNA damage in subjects exposed to long-term low-dose ionizing radiation. Toxicol Ind Health. 2011 Apr;27(3):205-12.
- Zhang HQ, Lin AP, Sun Y, Deng YM. Chemo- and radio-protective effects of polysaccharide of Spirulina platensis on hemopoietic system of mice and dogs. Acta Pharmacol Sin. 2001 Dec;22(12):1121-4.
- Schulpis KH, Papassotiriou I, Tsakiris S. 8-hydroxy-2-desoxyguanosine serum concentrations as a marker of DNA damage in patients with classical galactosaemia. Acta Paediatrica. 2006 Feb;95(2):164-9.
- Rong Y, Geng Z, Lau BH. Ginkgo biloba attenuates oxidative stress in macrophages and endothelial cells. Free Radic Biol Med. 1996;20(1):121-7.
- Dardano A, Ballardin M, Ferdeghini M, et al. Anticlastogenic effect of Ginkgo biloba extract in Graves’ disease patients receiving radioiodine therapy. J Clin Endocrinol Metab. 2007 Nov;92(11):4286-9.
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