Radiation is a bad thing that we don’t want to be exposed to, or so the conventional wisdom goes. We’re most familiar with it in the context of industrial risks and the stories of nuclear disasters that threaten entire cities and contaminate local food chains. It’s certainly not something you’d want anywhere near your dinner, right?
You might then be surprised to find that a great deal of research has been conducted into the process of food irradiation. It’s actually intended to ensure food is safer for human consumption, and has become widely used around the world.
Drop It Like It’s Hot
Food irradiation might sound like a process from an old science fiction movie, but it has a very real and very useful purpose. It’s a reliable way to eliminate pathogens and extend shelf life, with only a few specific drawbacks. Despite being approved by health organizations worldwide and used commercially since the 1950s, it remains one of the most misunderstood technologies in our food system.
The fundamental concept behind food irradiation is simple. Food is exposed to ionizing radiation in controlled doses in order to disrupt the DNA of harmful microorganisms, parasites, and insects. The method is both useful in single serving contexts, such as individual meal rations, as well as in bulk contexts, such as shipping large quantities of wheat. Irradiation can outright kill bacteria in food that’s intended for human consumption, or leave pests unable to reproduce, ensuring a shipment of grain doesn’t carry harmful insects across national borders.
It’s important to note that food irradiation doesn’t make the food itself radioactive. This process doesn’t make food radioactive any more than a chest X-ray makes your body radioactive, since the energy levels involved simply aren’t high enough. The radiation passes through the food, breaking the chemical bonds that make up the genetic material of unwanted organisms. It effectively sterilizes or kills them, ideally without significantly changing the food itself. It also can be used to reduce sprouting of some species like potatoes or onions, and also delay ripening of fruits post-harvest, thanks to its effect on microbes and enzymes that influence these processes.
The concept of food irradiation dates back a long way, far beyond what we would typically call the nuclear age. At the dawn of the 20th century, there was some interest in using then-novel X-rays to deal with pests in food and aid with preservation. A handful of patents were issued, though these had little impact outside the academic realm.
It was only in the years after World War II that things really kicked off in earnest, with the US Army in particular investing a great deal of money to investigate the potential benefits of food irradiation (also known as radurization). With the aid of modern, potent sources of radiation, studies were undertaken at laboratories at the Quartermaster Food and Container Institute, and later at the Natick R&D Command. Much early research focused on meats—specifically beef, poultry, and pork products. A technique was developed which involved cooking food, portioning it, and sealing it in vacuum packs. It would then be frozen and irradiated at a set minimum dose. This process was developed to the point that refrigeration became unnecessary in some cases, and avoided the need to use potentially harmful chemical preservatives in food. These were all highly desirable attributes which promised to improve military logistics.
Food irradiation eventually spread beyond research and into the mainstream.
The technology would eventually spread beyond military research. By the late 1950s, a German effort was irradiating spices at a commercial level. By 1985, the US Food and Drug Administration had approved irradiation of pork, which became a key target for radurization in order to deal with trichinosis parasites. In time, commercialized methods would be approved in a number of countries to control insects in fruits, vegetables, and bulk foods like legumes and grain, and to prevent sprouting during transport. NASA even began using irradiated foods for space missions in the 1970s, recognizing that traditional food preservation methods aren’t always practical when you’re orbiting Earth. This space-age application highlights one of irradiation’s key advantages—it works without chemicals and eliminates the need for ongoing refrigeration to avoid spoilage. That’s a huge benefit for space missions which can save a great deal of weight by not taking a fridge with them. It also helps astronauts avoid foodborne illnesses, which are incredibly impractical in the confines of a spaceship. Irradiated food has also been used in hospitals to protect immune-compromised patients from another potential source of infection.
How It’s Done
Three main types of radiation are used commercially to treat food. Gamma rays from cobalt-60 or cesium-137 sources penetrate deeply into food, and it’s possible to use these isotopes to produce uniform and controlled doses of radiation. Cobalt-60 is more commonly used, as it is easier to obtain and can be used with less risks. Isotope sources can’t be switched “off,” so are stored in water pools when not in use to absorb their radiation output. Electron beams, generated by linear accelerators, offer precise control of dosage, but have limited penetration depth into food, limiting their use cases to specific foods. X-rays, produced when high-energy electrons strike a metal target, combine the benefits of both gamma rays and electron beams. They have excellent penetration and can be easily controlled by switching the X-ray source on and off. The choice depends on the specific application, with factors like food density, package size, and required dose uniformity all playing roles. Whatever method is used, there’s generally no real risk of food becoming irradiated. That’s because the X-rays, electron beams, and gamma rays used for irradiation are all below the energy levels that would be required to actually impact the nucleus of the atoms in the food. Instead, they’re only strong enough to break chemical bonds. It is thus important to ensure the irradiation process does not cause harmful changes in whatever material the food is stored in; much research has gone into finding safe materials that are compatible with the irradiation process.
The dosage levels used in food irradiation are carefully calibrated and measured in units in Grays (Gy) or more typically, kiloGrays (kGy). Low doses of 0.1 to 1 kGy can inhibit sprouting in potatoes and onions or delay ripening in fruits. Medium doses of 1 to 10 kGy eliminate insects and reduce pathogenic bacteria. High doses above 10 kGy can sterilize foods for long-term storage or for space-or hospital-based use, though these doses are not as widely used for commercial food products.
By and large, irradiation does not have a major effect on a food’s taste, appearance, or texture. Studies have shown that irradiation can cause some minor changes to food’s nutritional content, as noted by the World Health Organization. However, while irradiation can highly degrade vitamins in a pure solution, in food items, losses are typically on the order of a few percent at most. The losses are often comparable to or less than those from traditional processing methods like canning or freezing. Changes to carbohydrates, proteins, and lipids are usually very limited. The US FDA, World Health Organization, and similar authorities in many countries have approved food irradiation in many contexts, with studies bearing out its overall safety.
In some extreme cases, though, irradiation can cause problems. In 2008, Orijen cat foods were recalled in Australia after the irradiated product was found to be causing illness in cats. This was not a result of any radioactive byproduct. Instead, the issue was that the high dose (>50 kGy) of radiation used had depleted vitamin A content in the food. Since pets are often fed a very limited diet, this led to nutrient deficiencies and the unfortunate deaths of a number of animals prior to being recalled.
The regulatory landscape varies significantly worldwide, both in dose levels and in labelling. While the United States allows irradiation of various foods including spices, fruits, vegetables, grains, and meats, rules mandate that irradiated products are clearly identified. The distinctive radura symbol—a stylized flower in a circle—must appear alongside text stating “treated with radiation” or “treated by irradiation.” Some countries have embraced the technology more fully; others less so. EU countries primarily allow radiation treatments for herbs and spices only, while in Brazil, just about any food may be irradiated to whatever dose deemed necessary, though doses above 10 kGy should have a legitimate technological purpose.
Overall, food irradiation is a a scary-sounding technology that actually makes food a lot safer. It’s not something we think about on the regular, but it has become an important part of the international food supply nonetheless. Where there are pests to prevent and pathogens to quash, irradiation can prove a useful tool to preserve the quality of food and protect those that eat it.
This guy likes to send various cameras through an electron beam irradiator for our viewing pleasure. Id imagine coming face to face with that feed horn/scanner would suck muchly.
https://youtu.be/Uf4Ux4SlyT4?si=4TLXSkj4mlj-OBl6
https://youtu.be/Uf4Ux4SlyT4 (no tracking id)
If prion disease is malformed proteins and irradiation can break bonds of molecules, can irradiation also cause artificial prion disease?</Tinfoil mode>
The example with the cats suffering vitamin shortage definitely proves that it destroys molecules and creates new junk molecules that have either no effect or science-knows-what-effect.
Nerd mode: If you really want to irradiate something and make it radioactive you only can via neutron activation in a reactor.
My former idea is not meant to spark conspiracy theories, but I don’t see a need for broken bonds and fragmented molecules in my food: Remember kids, lower doses still destroy the food and the bacteria, just because we don’t suffer vitamin shortage, doesn’t mean molecular fragments are not there. The dead bacteria died for a reason.
I suppose you could argue that irradiation can break bonds, make prions but then again heat from cooking does the same thing. Nothing is 100% safe, the question is do I prefer to give my grub the old Bruce Banner or my colon Montezuma’s revenge?
On a grill for sure and these form known carcinogens. Not every vitamin is heat sensitive and cooking denatures proteins. It’s definitely not the same as a gamma ray shattering a bond and have it recombine into anything new from free radicals. The energy level difference tells the tale.
If you don’t want to see broken bonds or fragmented molecules in your food: don’t boil it, fry it, grill it, ferment it. Don’t expose it to air or light. Don’t let it ripe or mature. Better not eat it at all.
Thus solving the problem once and for all.
And I forgot the most important one: don’t digest it!
Please read up on the Maillard reaction to understand that we alter molecules in food all the time.
‘the dead bacteria died for a reason’ is low on science, high on fear mongering; they’re not being poisoned by what the radiation does to the food, they’re being fatally damaged by the radiation. Think of boiling food for safety, you’d die along with the bacteria if you were boiled too but that doesn’t make the product inherently harmful once it’s cooled down a bit.
Actually, it probably does. Before people massively started using cooked foods in XIX century, cancer was something almost unhead of. As soon as we started cooking food, everyone started falling sick, be it leukemia, brain tumors or tummy cancer – didn’t matter child, adult or elderly.
The only safe food is fresh food. Period.
Nonsense. We have plenty of evidence our ancestors got cancer all the time. We also have plenty of evidence that wild animals get cancer (and always have, not just modern animals) all the time, and I guarantee most of them aren’t eating much cooked or irradiated food.
So we’re just completely ignoring the written work of Pliny the Elder here, huh? People got cancer often enough in Classical Greece that a cabbage poultice applied to the tumorous tissue was a common “remedy” written in the Historia Naturalis and preserved in the Medicina Plinii.
You can shove all the way off with this nonsense. Because it is nonsense, and I think you know that. I think you are very much aware of that, and you’re attempting to feed on people’s fear here. Do better or go find somewhere else to be.
Back then people only lived to be 35 on average and more than half of those born didn’t make it to age 5 so be careful when hearkening back to “better” times. Many types of cancer weren’t known back then so I’m not sure how good estimates could be made of their prevalence. As people live longer, diseases will become apparent in the statistics but it is important to place the numbers in context.
With respect to fresh food being the only safe food, that is false bordering on dangerous. Fresh food undoubtedly kills many many more people than food that has been properly protected from spoilage, even with modern food safety inspection programs. If irradiation causes one death in 10,000 but pathogens cause one death in 100, which would you choose?
Facepalm. Humans cook, ferment, grill, boil food since millenia.
Some other animals process their food since millions of years.
Before knowing what cancer was, the cancer rate was pretty much ZERO. A very real disease is the combination of ignorance and social media megaphone.
Total and utter new age bollocks. The Romans, Greeks and Egyptians described cancer. There are archeological finds of bone cancer dating long before that.
But cancer is a lottery: the longer you play, the bigger the chance you eventually “win”.
So with increased life expectancy comes increased cancer incidence.
Cancer was largely unheard of because it was very unusual to discover or record them. people had no idea what it was and there were so many other easy ways to die young before cancer had chance to develop in a higher percentage of populations.
Scientists and people also believed the earth was flat, that there was a man in the moon, that there were gods who controlled natural phenomena like thunder, that the ‘elements’ were earth, water air and fire, that sacrificing and burning animals or people would appease the gods and all sorts of other nonsense.
We learned better, how to spot disease, lived longer so cancers became more common and were better diagnosed, that the earth is actually an oblate sphere, that the ‘elements’ aren’t earth, water fire and air, we also live, on average, at least twice as long as the peoples who didn’t cook food etc. etc.etc.
Yes, some raw food is good but some raw food will make you seriously unwell and is far from ‘safe’ until cooked.
Hippocrates was one of the first westerners to diagnose cancer, and that’s why we use a greek word for it. There’s some debate about whether the Egyptians and Chinese also knew about cancer hundreds or even a thousand years before. https://pmc.ncbi.nlm.nih.gov/articles/PMC11591967/ But it’s well documented as a distinct diseases back in the 500-600s.
The ancient Greeks also knew not just that the earth was round, but had approximated the diameter by digging two holes of known depth at known distance, and got the answer right to like 1% in 200 BC. https://en.wikipedia.org/wiki/Eratosthenes
The Church insisted that the earth was flat for a while, pre-Renaissance, and people absolutely died younger before the Industrial Revolution. But cancer and navigation have been known and with us for millenia.
Cancer is nature’s reward for not dying by accident, disease or starvation earlier in life.
Hardly any ferrets or opossum eat cooked foods, yet cancer is endemic.
Granted the opossum diet is pretty dire and the opossum’s metabolism may be a factor, but they don’t cook their food.
It when you boil it, you’re pouring heat into the food, and the phlogiston kills it. But it could still be full of phlogiston, and that could kill you. That’s why you need to wash it in cold water to be sure you’ve safely removed all the phlogiston.
Philogiston? Relevant xkcd.
Naturally this should be done far from any source of vitiated airs, or it’s pointless.
you can create neutrons outside of a reactor though, all it takes is an alfa emitter and beryllium metal, mixed together in powder form. Bobs your Sodium-24 and phosphorus-32 emitting uncle.
Any double-blind studies? Or longitudinal studies? Any meta-study about who’s funded the existing research?
Irradiation works by shoving a hot poker, that is, a Co-60 gamma, into some biomass, leaving behind an ionization trail that, yes, kills pathogens. At the very least, it’s also going to leave behind a trail of free radicals, including reactive oxygen species. I’m not concern about a reduction in nutrition, but about the production of toxins. The research remains insufficient IMO.
Which is worse, radiation toxins or botulinum toxins? We should do a study.
Given the number of results on Pubmed, and how long this has been going on – plenty of “long term studies”. Also, free radicals do not stick around in complex matter – by definition, they are short term. “toxins” is such a vague terms its almost useless – water can be a toxin if you ingest enough of it. What are your specific concerns?
Ah.. Co-60. The good o’le drop and run stick!
Not arguing with any of the points in the article. Another not as nice reason this is done though is to make sure the buyer can’t plant seeds or cuttings in their garden and avoid buying again.
BRM (Biological Rights Management)?
Planting seeds from a F1 hybrid is basically a waste of time.
Each child plant will be a random mix of traits from the grandparent plants, not a predictable mix as the parent was.
” It effectively sterilizes or kills them, ideally without significantly changing the food itself ”
” significantly ” is a relative word meaning no wonder why our food supply is putting us all in a slow grave.
no, it means it works on wheat, soy, corn and dried herbs, but will turn salad into soup.
“…putting us all in a slow grave.”
https://ourworldindata.org/life-expectancy
That has nothing to do with irradiation and everything to do with too much food, too much highly processed (and by that I don’t mean irradiation) foods, too little fibre, too much red meats, wrong fats, too much salt, sugar, etc.
Hypertension and diabetes are what’s killing people. Giving food the agency of motive is populist, food is inert. UPF tend to be foods high in salt, sugar and saturated fats. These contribute to heart, kidney and liver diseases.
The holier than science opinions on nutrition are weird. Living without parasites and infections is a good thing. Viral encephalitis is bad, intestinal worms are bad. X Ray’s are harmless when used safely.
one could argue the intestinal worms would do more good than harm to a lot of people in the land of the fat.
Obligatory Gilligan’s Island episode.
wild that this article dros in the same day the FDA announced a recall because a bunch of shrimp is contaminated with cesnium-127.
It has nothing to do with irradiation, but thanks for trying.
In case anyone missed it, here’s one news article about the recall. Yeah, it’s not about irradiating food, it’s about radioactive stuff being in the same shipping container possibly contaminating the shrimp.
Yeah, right?! We could not have predicted that!
And despite being “radioactive”, it’s totally different. One is “exposed to radiation” and the other is “contaminated with hot cesium”. (Yoiks!)
My question: how does a shipment of cesium end up in the same container as frozen shrimp? My guess is that not all safety regulations were followed here…
And of course, xkcd.com did next-day-commentary (xkcd actual) on Cesium Shrimp.
Well this is one way to ensure the food supply is safe. Inspectors that inspect it are the other.
Quality control is important.
https://www.youtube.com/watch?v=44MgeRJN1Fw
When I lived on the East cost of the US, the Wegman’s grocery stores used to carry “irradiated ground beef” in tubes. The thing it was really useful for was making really rare hamburgers without having to worry about food poisoning.
As as astrophysicist though, I have to take a little issue with the statement that this doesn’t make food radioactive because the energy levels aren’t high enough. That makes it sound like shining more x-rays on something would change that. The energy levels of the x-rays and gamma rays that are used is enough to disrupt molecular bonds, hence the reason you can destroy vitamins. The energies required to disrupt atomic nuclei and change something from a stable isotope to an unstable isotope… that’s beyond anything that’s being used here. And, since there’s an energy threshold, more x-rays won’t change that. It’ll just make it warmer.
Also worth noting that this technology gets use to sterilize plenty of medical equipment.
I love raw steak. Irradiation is the only way to make it safe.
Nope. Take for example dry curing meat for weeks. It’s still raw, and no irradiation, no salt. Great flavor and tenderness (enzymes at work)
Irradiation is just a cheap, quick way to make it safe, but the flavor does not compare.
Unfortunately, it also kills seeds and destroys enzymes, limiting options in reducing antinutrients which have become all too prevalent in the modern diet.
Soaking or sprouting greatly reduces antinutrients (such as phytic acid, indigestible saccharides, oxalates) in seeds (such as nuts, grains, and pseudo grains), but unfortunately it’s rarely done in commercially prepared food, possibly because of the costs associated with it (time and potential contamination with the finished product) and lack of perceived (visible) differences. Nuts were once soaked before roasting, whereas now they are almost always dry roasted. Same “nutrition facts” but the dry roasted are less nutritious.
It doesn’t help that the “nutrition facts” only lists vitamins and minerals contained in the food but not their bioavailability, and hence they are misleading when choosing what foods to buy, because that calcium may come with oxalates or that iron and phosphorous may come with phytic acid, neutralizing their effectiveness. Bioavailability can be improved by consuming other types of food at the same time (e.g. heme iron or vitamin c with non-heme iron), so it is much more complicated to present than a simple chart.
The over concern about germs, price, and over simplified nutritional information has resulted in a western diet lacking the soaking, sprouting, and fermentation that has traditionally been a part of diets for millennia, and can at least partially explain the rise in dietary related inflammatory diseases such as diabetes, irritable bowel syndrome, food allergies, etc, and other nutritional issues such as osteoporosis.
Dont know about you, but in my neck of the woods, we eat fermented ghurkins and cucumbers along with our fermented herrings.
there is no big hazzard, I think regulations in EU are just fine.
for some producers outside EU it is just easy not to work or pay attention to hygiene /cross contamination, because all gets irridated
Few remarks – 1) “radiation … we don’t want to be exposed to” – we are, every day – natural radiation from bedrock, cosmic rays, C-14 and K-40 radionuclides naturally occurring in our bodies, plants, animals 2) people sometimes mistakenly think irradiation makes food radioactive.
2) the issue arises from neutron radiation. Might not be a common concept in english, but certainly is commonly used in many other languages.