Deadly Dining

These children were given a very cruel choice, I think, of either facing imminent starvation or the possibility of leukemia or lymphoma one, two, or three decades down the road. This is a very cruel choice indeed.

-George L. Tritsch, Ph.D., cancer research specialist
Roswell Park Memorial Institute
Buffalo, New York
testifying before the U.S. Congress on the study in which irradiated wheat was fed to children, 1987

When considering the safety of food exposed to ionizing radiation, one should keep in mind the often tragic history of previous technologies and chemicals that were approved for human use. Consider these examples:

• The synthetic female hormone DES (diethylstilbestrol) was prescribed for millions of expectant mothers in the late 1940s to early '50s. It was put on the market despite the fact that animal studies had found damage in the offspring of rats treated with DES. Although the women who took DES showed no adverse effects, more than two decades later, many of their daughters developed cervical or vaginal cancer as a result of prenatal exposure to DES. ²

• For nearly twenty years before the FDA declared a limited moratorium on silicone breast implants, their principal manufacturer-the Dow Corning Corporation-knew of the implants' health risks. One Dow Corning executive resigned from the company in protest when no one would listen to his warnings that silicone implants could rupture and leak 4 Yet the FDA did not investigate, approve, or regulate silicone implants until more than 2 million women had already had implants inserted.⁵

• In 1950, the FDA approved the use of cyclamates as a sweetener in everything from children's vitamins to canned ham. The approval was based on two-year feeding studies conducted by FDA scientists. In 1969, the Secretary of Health, Education, and Welfare (HEW) announced a ban on cyclamates. The ban was in response to tremendous public pressure and increasing evidence that cyclamates create toxic chemicals within the human body-toxic chemicals that cause birth defects, tumors, and other damage. Despite this evidence and the resulting ban, the FDA did not review its own research on cyclamates for nearly two decades. At that time it was discovered that the FDA had ignored evidence of the dangers of cyclamates.⁶ (See Chapter Three for more information on the FDA and cyclamates.)

In each of these cases, scientists pronounced these products safe, and the public faithfully believed them. Now, proponents of food irradiation tell us that it, too, is safe-a boon to humanity and the food supply. Are they right?

THE IMPACT OF RADIATION ON FOOD

Irradiated food is not radioactive. If you put a Geiger counter alongside the potatoes described in the last chapter, no telltale clicks would be heard. On a purely superficial level, the food is unchanged. On an atomic level, however, the food is not only longer-lasting, but radiomimetic.7 This word, which is rooted in the Latin word "radio," meaning "ray," and the Greek word "mimetikos," meaning "imitating," is at the heart of the food irradiation controversy. These radiomimetic foods, when ingested, can have effects that mimic those of actual exposure to ionizing radiation. Although the food itself is not radioactive, those who eat it are receiving an indirect exposure to the radiation used to process the food.

The irradiation of food can be accomplished using X-rays, electron beam generators, or gamma rays. Gamma and X-rays, like ordinary light waves and microwaves, are forms of electromagnetic radiation, but they have higher energies and shorter wavelengths. Gamma rays, which have more penetrating power, are the preferred source for the irradiation of food. (See Figure 2.1.)

Food molecules are made up of atoms that normally have no net electrical charge. Each atom has a nucleus containing neutrons, which have no charge, and protons, which are positively charged. Negatively charged electrons orbit around the nucleus.

Gamma rays change this molecular structure by knocking electrons out of atomic orbit. This alters the atom's electrical charge, making it either positive or negative. These newly charged particles are called ions or free radicals, and they are anything but benign. According to Eileen Roggenthen in Food Irradiation: Its Safety, Value, and Dangers:

The 13 electrons dislodged by the gamma ray create a cascade effect. They knock off approximately 30,000 electrons altogether as they ricochet and bounce around, turning the affected atoms into ions as well. Once a biological cell loses its electrical balance, the cell is destroyed.¹⁰

In other words, although the food may look the same, the living cells have been totally annihilated. Cell division has been stopped because DNA has been destroyed. Without cell division, the food cannot undergo the normal processes of ripening and decay. The extended shelf life of irradiated food is a function of this destruction of DNA, and a sign of significant chemical transformation.

But the effect does not stop with DNA. The ions, which are electrically unbalanced, seek out other ions with which to share electrons. New chemicals are thus formed. These new chemicals are called radiolytic products. They include formaldehyde and benzene, which are known to cause mutations, and are suspected of causing cancer.

Exposure to formaldehyde has been known to cause pneumonia, pulmonary edema, and death. It has also been shown to cause cancer in animals, and is considered to be a likely cancer-causing agent in humans.

Chronic exposure to benzene causes a depression of the hematopoeietic system, which means that the body's ability to produce various blood cells and other elements of blood is impaired. It has also been associated with an increased incidence of leukemia. One of the best known, and most hotly debated, studies of the effect of irradiated food on humans found an increased incidence of abnormal blood cells associated with leukemia in children fed irradiated wheat. (See page 37.)

How prevalent are these products in irradiated food? Very, according to George L. Tritsch, Ph.D., a cancer research specialist from the Roswell Park Memorial Institute in Buffalo, New York. In his testimony before the U.S. Congress, Dr. Tritsch stated that:

Irradiation of sucrose produces formaldehyde, a known mutagen. A mutagenic [capable of causing cellular mutations] dose is 0.05 milligrams, which is formed when 30 milligrams of sucrose is irradiated. Sugars are ubiquitous in foods, and more than 30 milligrams would be found in one portion of irradiated food.¹¹

In the mid-1960s, Russian researchers A.M. Kusin and E.G. Plyshevslzaya gave the radiolytic products of irradiation a more descriptive name-radiotoxines.¹² They isolated one class of these radiotoxines, called orthoquinones, from irradiated plants and injected them into living lab rats. The rats showed a 42-percent drop in their white blood cell count-a dramatic drop that was the same as the effects seen after direct exposure to 700 rads of ionizing radiation. In addition, new chemical products called unique radiolytic products (URPs) are formed, the effects of which are still unknown. These URPs are chemicals that have never been seen before in food. It is almost a certainty that no one will ever know what all these radiolytic products will be, as the effects of gamma rays travelling through food is by its nature a random event. Under standard FDA regulations for testing the safety of a chemical or additive, the protocol of the Russian researchers would be considered the norm. The chemical-in this case, radiolytic products-would be isolated and fed in large quantities to laboratory animals. If no problems developed, the chemical would be cleared for human consumption. If cancer, mutations, or other deleterious effects were found, the product would not be allowed on the market. Yet, in the vast majority of animal studies done thus far, it has been irradiated food, not the radiolytic products found in these foods, that has been fed to laboratory animals. As we shall see, the FDA has bypassed its own testing procedures by not requiring study of the effects of radiolytic products. While radiation is generally considered to be a method of sterilizing food products, and has been used for that purpose in hospital settings for many years (on a very limited basis), research has shown that it can have precisely the opposite effect on some microorganisms.

Aflatoxins are the most potent of all naturally occurring carcinogens1,000 times as deadly as the banned pesticide EDB. In medicine's "bible" of pathology, The Pathologic Basis of Disease, it is stated that "among the 30 known chemical carcinogens produced by plants and microorganisms, the potent hepatic carcinogen aflatoxin B is most important .... It is produced by some strains of Aspergillus flavus that thrive on improperly stored grains and peanuts."¹³ Irradiation has been shown to cause large increases in the growth of aflatoxins on foods (particularly grains and vegetables) infected by fungal spores. One study, conducted by the FDA itself in 1979, demonstrated that irradiation increases aflatoxin production by more than a hundredfold. ¹⁴

Beyond the risk of chemicals that are formed in food via the process of irradiation, there is also the problem of nutrients that are destroyed by irradiation. At the radiation levels currently being used, vitamins A, C, E, and K, and the entire B group are damaged by the process. Amino acids and polyunsaturated fatty acids are also affected. Milk is known to lose up to 70 percent of vitamins A, B1, and B2 when it is irradiated.¹⁵

Proponents of food irradiation point out that all food processing methods entail the loss of some nutritional value. Unfortunately, most irradiated foods will also undergo these other forms of food processing, further reducing their already depleted nutritional stores.

WHAT HAPPENS WHEN YOU EAT IT?

One of the central questions in the food irradiation debate is, "Are irradiated foods safe to eat?" Thousands of studies have been done on the effects of irradiated food, but the results of these studies are still the subject of controversy.

In investigating the safety of a particular chemical or treatment, there are two basic types of testing. One is carried out in test tubes and petri dishes, using isolated living cells and observing their response. Called in vitro testing, this is the first, and sometimes the last, step in toxicity testing.

The other testing method, in vivo testing, evaluates the effects of the substance in a living body. It can be carried out in almost any living organism, from cockroaches to college students. Scientific ethics generally preclude testing every substance on humans, so researchers usually start lower down on the evolutionary scale and extrapolate their findings to humans. In discussing food irradiation, I will present studies covering everything from plant cells to human white blood cells to mice, monkeys, and even human beings.

Although in vivo tests are of obvious relevance in determining safety, in vitro tests are also important. In 1983, the National Academy of Sciences' National Research Council concluded that in vitro tests of cellular mutations can be "considered sufficiently reliable for most regulatory and manufacturing decisions" and that "in vivo tests should be reserved for the relatively few cases where the results of simpler tests are ambiguous or the chemical in question is widely used [emphasis added]."¹⁶

When it comes to evaluating the risks of irradiated food, one of the simplest in vitro methods is to take human cells and grow them in a culture medium that includes an irradiated solution. Dr. Margery Shaw and Dr. Emmet Hayes of the University of Michigan Medical School performed such a study in the mid-1960s. They used human lymphocytes, white blood cells that play an essential role in the body's immune response. One form of lymphocyte-the T₄ helper cell-is destroyed by the AIDS virus, crippling the body's ability to fight off illness.

Drs. Shaw and Hayes irradiated a sucrose (sugar) solution with 2 million rads and stored the solution for several months. At the end of the storage period, the researchers took the irradiated solution and a nonirradiated control solution, and added various dilutions to test tubes containing whole blood and an appropriate culture medium for "feeding" the blood cells.

After seventy-two hours, the researchers examined the chromosomes of the lymphocytes contained within the blood. They found that even when the irradiated sucrose solution was less than 1 percent of the total culture, the solution was "extremely toxic to the lymphocytes." Cell division was reduced, and the chromosomes were grossly damaged." The researchers were unable to determine the exact frequency of the chromo somal breakage because of the "poor condition of the cells" and the fact that the chromosomes themselves appeared to be "shattered, or pulverized." ¹⁷

In contrast, the cultures containing an unirradiated sucrose solution had no such effect. After seventy-two hours in the solution, there was no apparent effect on the rate of cell division, and the chromosomes were not visibly damaged.

Next, the researchers limited the duration of the experiment to twenty-four hours. Among the numerous abnormalities found in the cells that had been exposed to irradiated sucrose were "exchange figures"-a phenomenon in which part of one chromosome attaches itself to another chromosome. The authors commented that "undoubtedly they [the exchange figures] were induced by the irradiated sucrose solutions because no exchanges were observed in the controls."¹⁸

The type of chromosomal damage observed in these studies has very serious health implications. Specific chromosomal abnormalities have been associated with leukemia, cancer, Down's syndrome, and many other diseases. A total of 50 percent of spontaneous abortions and 5 percent of stillbirths and infant deaths in the immediate postnatal period have been associated with chromosomal aberrations. ¹⁹

At around the same time Drs. Shaw and Hayes were conducting their research with human lymphocytes, a group of researchers at Cornell University was evaluating the impact of irradiated sucrose solutions on another type of cell-that of the humble carrot. ²⁰ They found that irradiated food containing sugar inhibited the growth of carrot cells, and that these effects were similar to the effect of direct irradiation of carrot cells.

Commenting on the Cornell findings in the July 1966 issue of Nature, G. Lofroth noted that there is not as wide a gap as one might think between humans and carrots.

So far, there is no evidence that any class of compounds which results in cytogenetic and cytotoxic changes (for example, mutation, cancer, chromosomal aberrations) is only operative in one type of cell but not in another. It is worth mentioning that the thalidomide disaster might have been prevented if an easily performed investigation of possible cytotoxic effects in plant cells had been made and if the validity of plant cells in such a test had been recognized. It must indeed be acknowledged that any compound causing cytogenetical or cytotoxic damage must be considered a potential hazard to any living cell or cell system-including man.²¹

While these research findings would seem, at first glance, to be fairly damning evidence of the potential danger of irradiated foods, they were (and are) not considered sufficient to stop food irradiation in its tracks. The effect of digestion and what scientists refer to as "the gastrointestinal barrier" must also be considered. Toxins that harm cells in culture may not be harmful after they have passed through the process of digestion. In order to fully determine the risks of irradiated foods, we must look at their effects as part of the food supply of living creatures.

One of the first studies of the effects of actually eating irradiated food was done in 1960 at the University of Illinois College of Medicine. ²² Researchers there fed mice a mixed diet of irradiated pork, chicken, milk, potatoes, and carrots, all of which can be irradiated under the FDA's current ruling.

Of the two strains of mice studied, several animals on the irradiated diet developed breathing problems so severe that they were unable to move about in their cages. A total of 17 percent died. During the autopsy, the researchers found that the mice had died of rupture and/or expansion of the heart. Each autopsy revealed the same sight, a "greatly distended" left atrium, which had moved the heart and lungs toward the right back wall of the chest. Frequently, a large blood clot occupied as much as 25 percent of the dilated atrium. The musculature of the wall of the atrium was stretched and often broken into pieces.²³

The University of Illinois researchers then decided to try a different food source-milk. In addition, they added a complete vitamin supplement to the mice's diet to counteract any nutritional deficiency. One group of animals received irradiated cooked milk. Another was fed irradiated uncooked milk. Of the two control groups, one was fed non-irradiated cooked milk, and the other was fed non-irradiated uncooked milk. The result?

Twenty five animals (83%) eating irradiated, uncooked milk died or were killed because of heart lesions occurring within 85 days after initiation of feeding (average: 66 days; range 48 to 85). Only four lesions have been observed during the same time period in the group fed irradiated cooked milk. No lesions developed in the controls.²⁴

Once again, the heart muscle had torn apart, causing the animals to bleed to death. This phenomenon became known as hemorrhagic syndrome. There was already some precedent for these results, since, in 1957, other University of Illinois researchers published similar findings. ²⁵ In that study, burst blood vessels were found not only in the heart, but also in the testicles and just under the skin.

Also in 1960, researchers at the Medical College of Virginia investigated hemorrhagic syndrome in lab rats fed irradiated beef. In this study, all the male rats consuming irradiated food died of hemorrhagic syndrome within thirty-four days.²⁶ In an attempt to control for the effect of hormones, the researchers castrated some of the rats to see if that would change the effect. The rats did indeed live longer-by twenty-nine days. But by sixty-three days, all the rats on the irradiated beef (male and female) had died.

More recently, Raltech Scientific Services, the research branch of Ralston Purina, investigated the effect of feeding irradiated chicken to mice. ²⁷ In these studies, the chicken was exposed to the same levels of radiation (5.6 million rads) that were being considered at that time for future use in meat and poultry.

One study showed testicular tumors and decreased life span in the mice that ate the irradiated chicken. These mice also had a higher incidence of cancer than the controls, although the authors said that statistical analysis could not be performed. In another of the Raltech studies, it was shown that lab animals that consume irradiated food have a higher incidence of kidney disease than do control animals. In discussing these data, the Raltech researchers noted that, "while no single finding from the study is highly illuminating, a collective assessment of study results argues against a definitive conclusion that the gamma irradiated test material was free of toxic properties [emphasis added]."²⁸

The Raltech researchers were not the first to find kidney damage in subjects fed irradiated food. A few years earlier, in 1978, A.I. Levina and A.E. Ivanov reported similar results in the Bulletin of Experimental Biological Medicine. ²⁹ They had undertaken their research after evaluating six other Russian research reports that found kidney damage in rats fed irradiated food. As they put it, "Some workers consider the prolonged ingestion of food consisting even in part of irradiated products can lead to definitive structural disturbances."³⁰

In the 1978 study, Levina and Ivanov found that prolonged feeding with irradiated food caused kidney changes consistent with membranousproliferative glomerulitis, a disorder characterized by abnormal cellular changes in the glomeruli of the kidneys. These changes can result in symptoms such as edema, hypertension, abdominal pain, and muscle wasting. Severe edema can cause breathing difficulties and deep chest pain. If untreated, this disorder can progress to end-stage renal disease, kidney failure, and death.

In discussing the possible causes for their findings, Levina and Ivanov had suggested that the damage was autoimmune in character. In other words, eating the irradiated food had caused biological changes that prompted the rats' immune systems to attack their own kidneys.

In 1981, Levina and Ivanov published once again. This time they confirmed the earlier Raltech studies that demonstrated damage to the testes of rats fed irradiated foods. ³¹

In both of their studies, Levina and Ivanov used radiation doses ranging from 25,000 to 5,600,000 rads. Throughout their work, these researchers found that the severity of the biological damage was closely related to the dose of radiation used on the food. Commenting on this, the researchers noted that:

The structural changes observed were similar in many respects to those arising in the tests during prolonged exposure to radiation. Radiotoxic substances [in the irradiated foods] capable of simulating the action of radiation in the body may be formed in irradiated cells .... It can therefore be suggested that prolonged entry of such substances into the body in the composition of irradiated food may give rise to morphological changes in the testes similar to the after effects of chronic irradiation.³²

The negative impact of irradiated food on the reproductive organs of the creatures that eat it is an area of particular concern. Damage to reproductive cells (ova and sperm) means damage to future generations. Investigating these risks requires looking at these future generations.

It is difficult to study the long-term effects of a drug, additive, or process on humans and their close biological relatives because of our relatively long life spans. To determine the possibly mutagenic effects of a drug in humans, we would have to risk a generation of malformed infants. Fruit flies, on the other hand, have very short life spans. As a result, they are often used to study the effects of an experimental treatment on future generations.

In 1963, a group of Indian scientists published the results of a study investigating the effects of irradiated food on fruit flies in Science. ³³ When flies were fed food exposed to 150,000 rads -- compared to the legal treatment of our fresh fruits and vegetables with 100,000 rads or of herbs and spices with 3,000,000 rads -- 10.7 percent of the offspring were found to contain visible mutations. This was almost three times the rate found in the control group (3.7 percent).

Some flies had only one wing, some had no wings, and others had curly wings, cut wings, bloated bodies, rotated abdomens, or half thoraxes. More than 0.5 percent of the offspring from the irradiated food group were stillborn. Among the control group, all births were live.

Within three years, researchers at San Diego State College published two studies that confirmed the finding of increased mutations in the offspring of flies fed irradiated food.^34,35 Then, in 1979, Raltech researchers reported their fruit fly findings to the U.S. Army. ³⁶

Raltech investigators put a new spin on the existing fruit fly research. They divided their test subjects into six groups. Two groups were fed chicken meat processed by normal means, one was fed electronirradiated chicken, one was fed gamma-irradiated chicken, and another received no chicken at all. The final control group, however, was the kicker. This group also did not receive chicken meat. Instead, it was fed TRIS, or (hydroxymethyl) aminomethane, a known carcinogen and mutagen.

The results? All of the flies that had consumed irradiated chicken, regardless of the method used, had fewer offspring than the controls. Flies fed gamma-irradiated chicken had seven times fewer offspring than those fed cooked chicken. Even the flies that were fed TRIS had four times more offspring than those in the gamma-irradiated group.³⁷

Despite what would seem a preponderance of in vivo and animal evidence indicating significant dangers in consuming irradiated foods, there have indeed been some human studies. One of the first occurred in 1953, when, as part of a university research project, a group of conscientious objectors went on a two-week diet of irradiated foods. ³⁸ Physical examinations revealed no damage at the time, but there was no long-term follow-up of the health of the men involved in the study.

In the mid-1970s, a research project conducted by India's National Institute of Nutrition (NIN) examined the effects of feeding irradiated wheat to fifteen chronically malnourished children. ³⁹ The children were divided into three groups of five each and fed a diet that included freshly irradiated wheat, irradiated wheat that had been stored for some time, or no irradiated wheat. The irradiated wheat had been subjected to 75,000 rads of ionizing radiation.

Of the children who ate freshly irradiated wheat, 80 percent (four out of five) developed strikingly abnormal white blood cells within one month. The specific cellular abnormality is known as polyploidy, which is an excess of genetic material (chromosomes) that is commonly associated with direct exposure to radiation, and has been linked to the development of senility and leukemia.

The children who ate freshly irradiated wheat showed more polyploid cells than those who ate stored irradiated wheat. The control group, however, showed no polyploid cells. These children consumed an identical, non-irradiated diet.

The obvious correlation between irradiated wheat and an excess of abnormal white blood cells led the researchers to conclude that, "though the biological significance of polyploidy is not clear, its association with malignancy makes it imperative that the wholesomeness of irradiated food be very carefully assessed."⁴⁰

Because this study involved humans rather than animals, it has been in the forefront of the debates over the safety of irradiated foods. Both pro and con sides point out that the children who developed polyploid cells had a normal number of chromosomes twenty-six weeks after the feeding was stopped. Proponents sometimes use this finding as "proof" that polyploidy is not really a danger, disregarding the fairly obvious fact that if food irradiation becomes the norm, exposure will continue and so, presumably, will the chromosomal aberrations. Opponents, on the other hand, point out that this finding demonstrates the cause-andeffect relationship between cellular mutations and the consumption of irradiated wheat. As Dr. Tritsch pointed out in his testimony before Congress:

This direct cause and effect relationship is unequivocal evidence of a potent mutagen in irradiated wheat, so potent in fact that polyploidy was seen in 4 out of 5 children.⁴¹

Dr. Tritsch also noted that when discussing lung cancer statistics (circa 1982-1983), a "high incidence" was considered 80 cases per 100,000 people-a mere 0.08 percent. The incidence of chromosomal damage in these children was 80 percent.

Since the NIN study, Chinese researchers have done extensive exploration of the impact of irradiated foods on humans. In a series of studies using a wide range of irradiated foods that generally made up 35 percent of the subjects' diets, these researchers found no significant increase in polyploidy among subjects fed irradiated foods.

However, the study was limited in time to a maximum of only fifteen weeks. In summarizing their data, the researchers noted that due to the relatively short duration of the feeding period, more long-term feeding studies should be conducted.

So, where does this leave us? According to the advocates of food irradiation, the Chinese study of the impact of irradiated food has shown that it is safe. But let's take a look at the complete picture.

In vivo studies have shown that irradiated foods (sucrose solutions) can cause cellular damage to a wide range of living cells-including those of the human immune system. In vitro studies of the radiolytic products of irradiation have demonstrated marked immune damage in laboratory animals exposed to these toxins. Lab animals fed a diet of irradiated food have shown increased incidences of cancer, fatal cardiac damage, and kidney damage. Further, in vitro studies using fruit flies have demonstrated impaired fertility and a high incidence of mutant offspring in flies fed irradiated chicken.

The evidence from human studies, while less clear-cut, is not encouraging and considered by many to be cause for alarm. The chromosomal abnormalities found in malnourished children fed irradiated wheat were also noted in studies with monkeys and rats. In the Chinese study, which is often cited as proof of the safety of irradiated foods, there was a higher incidence of polyploidy in the study groups that consumed higher percentages of irradiated foods. Perhaps the chromosomal changes were more dramatic in the Indian study because malnourished children are more susceptible to the negative effects of irradiated foods. Whatever the explanation, it is clear that the baleful association between polyploidy and the consumption of irradiated foods has not been disproved and is in fact a consistent finding-to varying degrees-in research in which a portion of the diet is irradiated. If the FDA's ruling stands, irradiated foods may well make up a far greater percentage of our diet-for a much longer time-than they did in any of the human studies conducted thus far.

The preponderance of the evidence points toward serious danger in the wholesale adoption of food irradiation. Yet the FDA, so cautious in the matter of AIDS medications and contraceptives, has wholeheartedly embraced food irradiation as the wave of the future.