Doctors appear to be causing tens of thousands of cancers with CT scans and dentists may be causing a few brain tumors with dental X-rays (see my two videos Cancer Risk from CT Scan Radiation and Do Dental X-Rays Cause Brain Tumors?), but what about these new-fangled airport full-body scanners that use so-called backscatter technology to reduce X-ray exposure? A thousand times less radiation exposure than a chest X-ray, though they’re still being phased out. In fact, flight passengers may get 100 times more radiation during the flight every hour, because they’re so high up in the atmosphere and exposed to more cosmic rays. Does that mean a round-trip cross-country flight is almost like getting a chest X-ray? Yes. Anyone who’s seen my speaking schedule knows I’m totally screwed. But what can you do? As is the answer to so many health questions, you can eat healthily.
High dietary antioxidant intakes are associated with decreased DNA damage in airline pilots. Note the word “dietary.” Antioxidant supplements didn’t work. No benefit was found for those taking multivitamins, vitamin C pills, or vitamin E pills. But those getting the most vitamin C from food, B carotene from food, cryptoxanthin from food, and lutein/zeaxanthin from food, saw a significant decrease in DNA damage.
The USDA keeps a nice list of phytonutrient resources. Cryptoxanthin sources listed here (Healthy Pumpkin Pie anyone?). Lutein and zeaxanthin can help us Prevent Glaucoma and See 27 Miles Farther and may present a Dietary Prevention of Age-Related Macular Degeneration. Are these eyesight-saving phytonutrients also found in eggs? You might be surprised. See Egg Industry Blind Spot.
For more on why produce is generally preferable to pills, check out:
- Can Folic Acid Be Harmful?
- Lutein, Lycopene, and Selenium Pills
- Produce, Not Pills to Increase Physical Attractiveness
- Risk Associated With Iron Supplements
- Some Dietary Supplements May Be More Than a Waste of Money
- Update on Juice Plus+®
- Update on Vitamin E
These are all phytonutrients, of course, so when they say food, they really mean plants. And because antioxidants can have synergistic effects, the greatest protection was found when they were eating a combination of phytonutrients, so the greatest protection was found in those eating the citrus and broccoli and nuts and seeds and pumpkins and peppers and dark green leafy vegetables. Though if one had to pick, greens may be the best. All this time I’ve been packing kale chips on planes as a snack just because they’re so lightweight, but now I know their dual purpose.
The researchers conclude that a diet consisting of a variety of fruits and vegetables provides a natural source of these antioxidants as well as other potential protective factors, which may offer the best protection against cumulative DNA damage associated with ionizing radiation exposure. The results are especially relevant to flight crews, astronauts, and frequent flyers.
The same thing was found following Hiroshima and Nagasaki atomic bomb survivors for decades. Models based on the available data suggest that the cancer risk in exposed persons may have been knocked down by daily green and yellow vegetable consumption from about 50% increased cancer risk to only about 30% increased risk. Similar results were found for fruit consumption. So fruit and vegetable consumption can diminish, but not eliminate the risks of radiation.
Same thing was found following children after Chernobyl. I profile a study in my video Mediating Radiation Exposure From Airline Travel in which consumption of fresh vegetables and fruits was found to afford protection to the immune systems of exposed children, whereas egg and fish consumption was associated with significantly increased risk of chromosome damage within their bodies. Researchers were unsure whether the damage attributed to fish and eggs was because the eggs and fish carried radioactivity, or whether it was just from the animal fat intake alone.
Why might eggs be harmful even if not radioactive? See Who Says Eggs Aren’t Healthy or Safe? or my other 58 videos on eggs. I cover natural and artificial radioactivity in fish in Fukushima and Radioactivity in Seafood and explore concerns about other pollutants in my 89 fish videos.
For interventional studies where plant foods are actually put to the test, see Reducing Radiation Damage With Ginger And Lemon Balm.
-Michael Greger, M.D.
Every year, doctors cause an estimated 29,000 cancers a year dosing patients with X-rays during CAT scans (see Cancer Risk from CT Scan Radiation). What about dentists? 100 million Americans are exposed to dental X-rays every year, but don’t the lead apron and thyroid shield protect our vital organs? All our vital organs except one, our brain!
A study entitled “Dental X-Rays and Risk of Meningioma,” was recently published. The objective was to explore the association between dental X-rays—the most common artificial source of high-energy radiation—and the risk of intracranial meningioma, the most common type of brain tumor.
The researchers found that those who report ever having a bitewing X-ray had twice the odds of a brain tumor, and those that got a panoramic series—the full mouth X-rays—before age 10 had nearly 5 times the odds (see my 3-min video Do Dental X-Rays Cause Brain Tumors? for details).
While more research is needed, the bottom line is the benefits and risks of radiation exposure must always be carefully weighed. Dentists should consider the justification for every exposure. Furthermore, dentists should not prescribe routine dental X-rays at preset intervals for all patients (such as every 6 months or year, etc.). Says who? Says the official recommendations of the American Dental Association. There is little evidence to support irradiating people looking at all the teeth in search of hidden problems in asymptomatic patients. Accordingly, dentists should select patients wisely—only take X-rays when there is patient-specific reason to believe there is a reasonable expectation the X-rays will offer unique information influencing diagnosis or treatment.
The last time I was at at the dentist for my check-up I was again offered a set of full mouth X-rays (because I was “due”). Normally when I refuse routine dental X-rays I’ve just explained that I try to minimize my radiation exposure, but this time I was able to refuse “as per the official recommendation of the American Dental Association!” I just got a blank stare.
More on avoiding brain tumors in:
- When Nitrites Go Bad
- #1 Anticancer Vegetable
- Do Cell Phones Cause Cancer?
- IGF-1 as One-Stop Cancer Shop
- The Inflammatory Meat Molecule Neu5Gc
This is the third in a five part video series on preventing and mediating the adverse effects of radiation exposure. The first, Fukushima and Radioactivity in Seafood, described the natural and artificial sources of radioactive isotopes in our diet. The previous video, Cancer Risk from CT Scan Radiation detailed the estimated 29,000 cancers that doctors cause with CAT scans every year. I also have videos on Mediating Radiation Exposure from Air Travel, in which I talk about those full-body scanners in airports. And I close out with ways to mediate all these risks with Reducing Radiation Damage With Ginger And Lemon Balm.
-Michael Greger, M.D.
Image credit: bolandrotor / Flickr