Doctor's Note

For more on the cancer risk associated with CAT scans and dental X-rays see my last two videos Cancer Risk from CT Scan Radiation and Do Dental X-Rays Cause Brain Tumors? Wednesday I'll review interventional studies where plant foods are actually put to the test in Reducing Radiation Damage With Ginger And Lemon Balm.

Those who want to count my chest X-ray equivalents can view my speaking schedule here—just don't tell me!

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. Are these eyesight-saving phytonutrients also found in eggs? You might be surprised: Egg Industry Blind Spot.

For more on why produce is generally preferable to pills, check out:

Why might eggs be harmful even if not radioactive? See Egg Cholesterol in the Diet or my other 57 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 more context, check out my associated blogs: Are Dental X-Rays Safe?, Fukushima Radiation and Seafood, How Risky are CT Scans?, and Ginger & Lemon Balm for Radiation Exposure.

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  • elsie blanche

    Dr. Greger, If our bodies are being potentially damaged during long distance plane trips, is the food that is sitting in our laps during these trips also experiencing some sort of DNA damage, negative alteration, that we are then consuming during the flight? I can’t help but wonder if one is actually better off not eating or drinking during these flights (dehydration would set in, though). And are medicines, vitamins, supplements being “damaged” up in the air during these trips? Makes me wonder what happens to a mother’s breast milk during these flights. Truly hoping you have some information and suggestions on all of this.

    • Void_Queen

      You bring up a good point that the DNA of our food should get damaged too during flights, but I don’t think it matters. What we want out of food is antioxidants and vitamins (and whatever other goodness) which as far as I know will still be there even after they’ve been exposed to some in flight radiation. I don’t think it will matter that the DNA of our food is damaged because we don’t use that DNA. The digestive enzymes in our stomach will break apart the cells of our food, break apart the nucleus and eventually break apart the DNA, damaged or not. The reason damage to our DNA is bad is because it might cause a mutation which will lead to problems as the DNA of that cell is replicated and used to make proteins.

  • Nancy Robbins

    By Dr. Mercola

    A little-known carotenoid called astaxanthin is now believed to be the most beneficial antioxidant nature has to offer. Astaxanthin’s benefits are so numerous, I’ve written several articles to cover its many activities, from UV-radiation protection, to eye and heart health, to improved athletic performance.

    • Coacervate

      My opinion as a biochemist with 35 years in the food industry is that any single antioxidant is going to be much less effective and possibly dangerous than a broad spectrum of antioxidants in your diet. The problem stems from the way antioxidants mitigate against damage.

      A high energy radical such as singlet oxygen reacts with an acceptor molecule. Hopefully this acceptor is an antioxidant and not your DNA. If you only have 1 type of antioxidant then you build up a high concentration of high energy oxidized antioxidants (aka, radicals). These oxidized molecules, although less energetic than singlet oxygen, are still able to inflict damage.

      You need to have a range of antioxidants to form a kind of energy absorbing cascade, each taking some of the energy out of the “hit” in turn until it arrives at the liver in a form ready for safe tagging and elimination via the kidney.

      By way of analogy, a bullet will pass through a single layer of plastic but if you build up enough layers it will be stopped because the energy has been absorbed a little at a time, one layer at a time.

      Also, ask yourself, among the Drs who are in the media, who offers a maximum of science data with a minimum of words like miracle and paypal? Hint: Starts with a G, rhymes with Dr. Greger.

      • Thea

        Coacervate: That’s an awesome explanation. You gave an understandable explanation as to *why* eating a variety of antioxidant whole foods appears to provide the most protection (as explained in the video). Thanks.

  • Plantstrongdoc MD

    Happy I ordered vegan-lunch on my upcoming flight to Spain! :-)

    • elsie blanche

      Yes, but is your vegan lunch somehow being denatured, nuked, DNA-altered/damaged (whatever one should call it) way up high in the air? Just as our bodies are being harmed, are the “bodies” of fruit and veggies somehow being harmed, and then we’re ingesting this “harm?”Looks like I’ll be calling NASA . Standby, this may take longer than a trip to mars to get answers on this one.

      • Coacervate

        Elsie, my educated guess is that the gross amount of damage is so low it would be barely detectable in food. The problem is the relatively small amount of damage done to flying people includes their functioning DNA. If you happen to have a compromised DNA repair system too then you are at high risk.

        However, what about irradiated food that has been exposed to very high doses of ionizing radiation. Eating that food is not likely to damage your DNA (I don’t think), but the rads ARE high enough to compromise nutritional quality … although the Machine keeps telling us not to worry about it. “Pay no attention to that man behind the curtain!”

        I have looked for and never found a risk benefit analysis or even an acknowledgement that there is risk from irradiated food. “Care for a dose of free radicals Scarecrow?”

        • elsie blanche

          Thank you for taking the time to think about this. The whole issue of zapping, x-raying, air-travel-damaging our food concerns me, as you can probably tell. Many of the shipping containers at US ports getting x-rayed for contraband, the same shipping containers bringing over many vegan products, supplements, nuts, seeds, the list goes on. A lifetime of eating zapped food. Maybe these studies are decades away.

          • Coacervate

            Yes, I see what you mean. I don’t know if it would be practical or even possible for this site to be the starting point for a political action group of some dimension. We should have a voice in how our research $ are spent. Who sets the priorities? It seems as though there are forces at play that think that we cant handle the truth.

            One thing I can envision is Dr. G confronting the congress critters directly with science. “Have I got a Package Deal for you….” Jimmy Stewart would have been proud!

            For the record, I keep my name secret because I know what can happen when I speak truthfully about food science and the food industry. It is not pretty. That is another reason I admire Dr’s Greger, Campbell, Esselstyn and others. Takes more guts than I have.

        • b00mer

          Hi Coacervate,

          Another biochemist here (with considerably less experience than you!), and I actually just got done teaching the nuclear chemistry portion of my freshman chem course. There was a section in the text about irradiated food, which summarized that 1) concerns about the food itself becoming radioactive have no evidence to support them, 2) destruction of nutrients is however a very real concern, and 3) the radicals produced can of course go on to combine with other molecules, although the same effects result from cooking with heat. It’s unclear whether they’re simply stating that the same process (ie radical formation) occurs, or whether it’s to the same degree. It did mention food irradiation as having an “uncertain future”, but that was in the context of nutrient loss, which seems to be the main concern.

          • Coacervate

            Hi Boomer,

            Although my life of education has hurt me some, i’ve managed to unlearn a great deal over the years.

            Of course I have not taken your course and have no reason to doubt your qualifications BUT Your cited text is a good example of how the lobby works:

            “the radicals produced can of course go on to combine with other molecules, although the same effects result from cooking with heat.”

            The statement is simulatneously both sorta true and a lie. The key point that is being glossed over has to do with the energy levels, the bonds broken. Do you notice anything strange about equating heat energy with gamma rays?

            Which would you prefer, a match-burned finger, a sun burn or the same wattage in gamma rays? Why?

            Peer reviewed scientific publication is rife with false spin doctoring to suit the goals of the funders. And of course physics tells us that the magnitude of the spin is directly proportional to the size of the grant. (heh)

            The concern about nutrient loss is just smoke to get you focused on an easily solved problem.

            For me the war is over, I’ve tried to do what I can to promote critical thinking. Now it is your turn. Fortify yourself with strong green tea and into the breach once more. Ka Boom!

            so bottom line, is food irradiation helpful, harmful or neither?

          • b00mer

            Hi Coacervate,

            I should have been clearer; those words were my paraphrasing, not the actual text. My key point at the end there was that it was unclear whether the end result was what they were equating (i.e simply that radicals are formed) or whether they are saying that it’s happening to the same degree, which based purely on my intuition at this point, I would also doubt. I would agree with you that equating heat and gamma rays is silly, but it should be said that I’m not sure the text was doing that. Their phrasing was ambiguous.

            I also agree with your suspicion regarding “the lobby”. I took many opportunities to show the students examples of biases of omission or emphasis. You can go through an entire chapter on atmospheric chemistry plus “educational” films (pbs specials are now “brought to you by David Koch”…) and not a peep about livestock. The text focuses almost exclusively on CO2, with literally a one sentence mention of the other greenhouse gases. Let’s everyone bend over backwards spending $100,000 on a tablespoon of biofuels, debate the safety of fission based reactors, discuss the logistical struggles of raising efficiency standards, but don’t bother mentioning the single biggest contributing factor to greenhouse gas emissions. Another example: regarding equilibrium and how to get your hens to produce thicker eggshells and I had to inform the class that also, leaving the hens alone was another alternative. Another example: repeated misuse of the term “essential” in reference to amino acids.

            So throughout the semester I give them a pretty heavy handed spiel about not believing everything you read, no matter how authoritative the source appears, thinking beyond the inevitably filtered material that was presented, and checking source affiliations when possible.

            Now regarding the literature, I agree that being written by humans, it’s as fallible as any other medium, but that said, I cringe when I hear people dismissing the integrity of science as a whole (which you didn’t do here, but it’s something I hear often). When it comes to our funding, some proposals get funded and some (most :) ) don’t, so obviously there is bias in that. But at the end of the day, our projects are our own ideas, and the only pressure from NIH/NCI/NSF/etc is that we get results. They have no influence on what those results are, and we have never had any problems with publishing. That said, we know our place in academia, doing the initial work and publishing it in the public realm so that industry can take it, pick up where we left off and make a buck.

            I bring a mug of green tea with me every day to class :)

            Bottom line, given the choice, I would choose non-irradiated food over irradiated, but it’s not something I’m going to lose sleep over. Also cost/benefit analysis may be different for someone else living in remote or austere conditions, or in different situations like supplying troops with food, etc.

            Apologies for the tome. You caught me mid-latte. I will just say that teaching these young people is a wonderful experience. They are still deciding who they’re going to be, and they don’t have the lifetime of being so sure who they are and what they believe that they’re unwilling to think critically. They welcome it. It’s exciting to them, not frightening. They give me hope for the future.

  • BPCveg

    Dr. Greger, your frequent flying habits may not necessarily be as harmful as you think!

    Researchers in the field of radiobiology are actively exploring the hypothesis known as radiation hormesis, which states that low doses of radiation reduce cancer risk by stimulating beneficial repair mechanisms in the body. Although there is currently no scientific consensus in support of radiation hormesis, this counter-intuitive theory does seem credible. See for example:

    http://dose-response.metapress.com/media/2724frttmr4ynmlpgw97/contributions/a/1/6/g/a16g412m35450318.pdf

    The jury is still out. But, if this line of thinking ultimately pans out, flying may one day be considered beneficial for cancer prevention (provided, of course, you continue to munch on your vegan sandwich while flying).

    • Coacervate

      Is that the same as the “J-curve” we saw in the alcohol/cancer vids?

      so you lob in a grenade, your body sends in the Marines and they mop up the whole area, clearing out any bands of outlaws and bandits hiding in your tissues? sounds like a plan.

      We could test it with mice….send in the murines, heh.

      • BPCveg

        Right on dude!

  • Darryl

    Among 19,184 male pilots,

    all-cause and all-cancer mortality was low for all exposure categories. A significant negative risk trend for all-cause mortality was seen with increasing dose.

    .
    28,000 male cockpit crew may have elevated melanoma risk,

    Overall cancer mortality was decreased (SMR = 0.68). We found an increased mortality from malignant melanoma (SMR = 1.78) and a reduced mortality from lung cancer (SMR = 0.53). No consistent association between employment period or duration and cancer mortality was observed.

    High-altitude cosmic radiation might not be the melanoma culprit,

    Internal analyses revealed no differences in skin melanoma rates between flight crew and air traffic control officers and identified skin that burns easily when exposed to sunlight and sunbathing to get a tan as the strongest risk predictors of skin melanoma in both occupations.

    Less equivocal outcomes are seen among female flight attendants, where there’s a roughly 11% increased cancer risk

    Meta-analysis showed a significant excess of melanoma (meta-SIR 2.15, and breast carcinoma (meta-SIR 1.40) and a slight but not significant excess of cancer incidence across types (meta-SIR 1.11, PI 0.98-1.25).

  • Just a vegan guy

    Kale chips taste SOOOOO GOOD!!! (I like the ones from Trader Joes)

  • Burgess Laughlin

    Should the title say “mitigate” not “mediate”?

  • R Ian Flett

    The hormesis theory is looking stronger with time. The increases in cancer with aircrew seem more related to disruption in circadian rhythms as occurs with other shift workers. It has long been noted that alpha-lipoic acid offsets radiation exposure. The cosmonauts took it as did Chernobyl victims.