What is the truth about them?
Regular optical colonoscopies often require drinking upward of a gallon of laxative fluid beforehand, then being probed with an endoscope. “Virtual colonoscopies” use CT scans to construct images of the colon, as well as to digitally “clean” the organ. A new study, funded by industry, says that virtual colonoscopies are as effective as standard colonoscopy at finding polyps, or growths on the lining of the colon, one centimeter or larger. Most polyps are benign, but some can turn cancerous.
What the study—and the press release—fail to mention is that these CT scans will expose you to extremely high levels of radiation, which dramatically increases your risk of cancer. So this new technology may actually cause cancer instead of protecting you from it!
What are the major media reporting about this? Every article we see is favorable to virtual colonoscopy; if they mention the radiation issue at all, it is dismissed offhandedly. They don’t even question the fact that the study was funded by industry, or think to look at the results critically.
Two years ago, scientists within the FDA complained that their concerns over the radiation exposure from virtual colonoscopies were being ignored by the agency. After an FDA official recommended approving General Electric’s application to use CT scans for colon cancer screenings, two noted physicians who worked for FDA—a gastroenterologist who trained at Oxford University and the Mayo Clinic, and a former professor of radiology at both Yale and Cornell—expressed their concerns that virtual colonoscopies could “expose a number of Americans to a risk of radiation that is unwarranted and may lead to instances of solid organ abdominal cancer” and that “the increased radiation exposure to the population could be substantial and would raise a serious public health/public policy issue.”
How much risk were the scientists talking about?
Human beings, on average, receive a background dose of 2.4 mSv (millisieverts, the standard measurement of radiation) per year from natural cosmic and terrestrial radiation. So that’s our baseline.
There have been three major sources of information on the correlation between radiation and cancer risk:
- an ongoing landmark mortality study (in progress since 1950) on 120,000 survivors of the atomic bombs dropped on Hiroshima and Nagasaki;
- a fifteen-country collaborative study of cancer risk among 407,391 radiation workers in the nuclear industry; and
- a 2008 study from Brigham and Women’s Hospital in Boston, in which researchers estimated the potential risk of cancer from CT scans in 31,462 patients over 22 years.
This is what we’ve learned from them:
- Colonoscopy CT scans average 10 mSv per scan. A whole-body CT scan is 20 mSv or more. Patients who have multiple CT scans have up to 12% higher than average risk of cancer.
- If you get two virtual colonoscopies, you get as much radiation as the maximum allowed per year for nuclear industry workers—20 mSv. Nuclear workers, by the way, have a 27.5% higher death rate from cancer than the general population.
- If you receive ten CT scans in your life, you get as much radiation as did the survivors of Hiroshima and Nagasaki—about 200 mSv. The A-bomb survivors have had 46% more deaths from leukemia and 11% more solid cancer occurrences (tumors) than the general population.
- Some patients in the CT scan study had received as many as 70 scans over seven years, and received 579 mSv—nearly three times the amount of radiation received by people standing just 1.5 miles away from the epicenter of an atomic bomb, and about 21 times the amount received by those 2.5 miles away. It is unlikely that any one doctor of these patients was aware of all the scans they had.
- An estimated 70 million CT scans are performed in the United States every year, with as many as 14,000 people dying every year of radiation-induced cancers.
Life Extension founder William Falloon reports:
As risky as properly done CT scans are, reports published at the end of 2009 exposed instances of major medical centers being so sloppy in adjusting the settings on their CT scanners that patients were exposed to up to eight times the normal radiation dose.
According to the New England Journal of Medicine, children receive four million CT scans per year, and of course their bodies are far more vulnerable to radiation than older people. William Falloon again:
Children are more vulnerable to the long-term effects of the DNA damage inflicted by X-rays. In one particularly heinous case, a 30-month-old child was exposed to more than 60 minutes of continuous CT scans when the normal time period is only 2-3 minutes. The hospital’s radiology manager called the overdose a “rogue act of insanity” while the chief of the state’s regulatory division said it was “one of the more egregious, extreme cases that I have ever seen.”
The journal Radiation Research just published a study showing that children who were under ten years of age when they were exposed to the Hiroshima and Nagasaki radiation have had a 58% higher death rate than average.
This same study also presents the strongest evidence to date that cancer risk not only exists at low doses of radiation, but may be even greater per unit of dose than at higher doses—and that ionizing radiation is associated with non-cancer diseases involving circulatory, respiratory, and digestive systems.
If you can’t avoid getting a CT scan or an x-ray, you need to know that the damage from radiation comes from hydroxyl free radicals, and you can protect yourself against them by taking antioxidants for several days before and immediately after receiving the radiation. The best antioxidants in this case are vitamin C, alpha-lipoic acid, n-acetylcysteine (NAC), mixed-tocopherol vitamin E, selenium, and CoQ10.
You should also take antioxidants before a long airplane trip because of the surprising amount of radiation you receive during flights. Airline crew and frequent fliers can receive up to about 5 mSv per year from their hours in the air.
We’ve talked a lot about “virtual” colonoscopies in this article, but regular optical colonoscopies have their own risks too, of course. For one thing, endoscopic equipment is disinfected but not necessarily sterilized because the flexible tubing can be destroyed by the sterilization process. This can lead to illness, which has prompted a recent lawsuit in Oregon. And an investigation revealed that between 2004 and 2009, over 11,000 colonoscopies were performed at three different Veterans Administration hospitals using improperly sterilized equipment; as a result of those colonoscopies, 13 of those veterans tested positive for hepatitis B, 34 for hepatitis C and 6 for HIV, according to the VA.
The rate of bowel puncture from regular colonoscopies is also a serious risk, not to mention complications from sedatives and possible long-term injury to the anal sphincter, which could lead to incontinence. We need a much better and safer test than colonoscopy—and we should be able to get one in the form of a blood or stool test. There are stool tests now, but with too many false positives and negatives. The technology needs serious refinement, but gets little attention because colonoscopy is such a thriving and lucrative industry. Who exactly is going to fund research into a safe, low-cost test when a high-cost (albeit dangerous) test is already available?
