A new study just published in the New England Journal of Medicine points out yet-again the growing risk due to low-level radiation associated with the increasing use of CAT scans and other sophisticated radiological procedures. The study looked at the cumulative radiation received by “952,420 nonelderly adults (between 18 and 64 years of age) in five health care markets across the United States between January 1, 2005, and December 31, 2007.” — “Computed tomographic and nuclear imaging accounted for 75.4% of the cumulative effective dose, with 81.8% of the total administered in outpatient settings.” – “Conclusions: Imaging procedures are an important source of exposure to ionizing radiation in the United States and can result in high cumulative effective doses of radiation(ref).”
As most readers here probably know, oxidative damage is the oldest and most established theory of aging and ionizing radiation is a prime source of free radicals (reactive oxidative species, or ROS). In short, the medical radiation can be a prime source of aging. The increase in use of CAT scans is part of a shift in the general practice of medicine. The orders for the CAT scans come not from the radiologists who read the results but from other doctors who see them as part of their regular diagnostic toolkit, like cardiologists, oncologists, pulmonologists, rheumatologists and especially emergency room doctors. Some patients with chronic diseases may undergo a half-dozen or more CAT scans a year.
While avoiding the CAT scans and the associated radiation may be difficult or unwise given the change in the practice of medicine, there is another approach that can contribute to minimizing the radiation damage. I wrote a paper treating this subject in 2008 which is available online Protection Against Radiation – The Second Line of Defense. Basically, the protective idea is to take antioxidants. I suggest reading this paper for anyone expecting to undergo extensive diagnostic x-radiation. I repeat the summary of this paper here.
The increasing use of diagnostic radiology is unquestionably beneficial. However, per-capita exposure to medical radiation has grown some six fold in the last two decades and appears to be still increasing. The issue of medical radiation protection is therefore achieving central importance for the health of both patients and radiation professionals. It is well established that the effects of radiation are cumulative and lead to increased incidence of cancers, cell deaths, genetic damage and numerous forms of body tissue pathology.
The first line of defense against gamma and X radiation damage, long established in clinical practice, is simply radiation avoidance such as by use of shorter exposure and more sensitive film, carefully focused beams, lead aprons and other shielding.
This paper is concerned with a second and complimentary line of defense one not yet established in clinical practice but potentially of great importance. That is, radiation damage minimization by interfering with the biological mechanism of radiation damage, that is, interfering with the propagation in tissues of free radicals created by X-rays. This kind of protection can be achieved through using commonly-available antioxidant supplements.
Despite the large body of research supporting the effectiveness of antioxidants to quench radiation-induced free radicals, this second line of defense against radiation damage is neither taught to radiology students in medical schools nor is embodied in general clinical radiology practice. The author discusses the research basis for widespread adoption of this “second line of defense” for radiation protection and provides some 60 research citations to support his points.
The paper also discusses the use of specific antioxidants for radiation protection and cites some 60 studies on the radioprotectivity of specific antioxidants. The paper is relevant not only to patients but also to interventional radiologist, radiation technicians and atomic-technology workers who are repeatedly exposed to low doses of ionizing radiation.