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Monday, April 13, 2009

MYTH: Natural is good and man-made is bad

There is a misconception that human exposures to carcinogens and other toxins are nearly all due to synthetic chemicals. On the contrary, the amount of synthetic pesticide residues in plant foods are insignificant compared to the amount of natural pesticides produced by plants themselves. Of all dietary pesticides, 99.99 percent are natural.

  • Natural vs. Synthetic

  • Natural Toxins in Food

  • Natural Poisons

  • 99.99% of all the Pesticides we eat are Natural Pesticides

  • DDT and Malaria
One of the craziest myths of all time is forced upon us every day: “Natural is good and man-made is bad.” This is a fallacy. There is no difference whatsoever between a “natural” chemical, such as Vitamin C (ascorbic acid) from a fruit, and a synthetic sample of the same material. It is also not the case that “natural” chemicals, i.e., those produced by plants and animals, are always “good” while “man-made” chemicals are always “bad.”

The idea that there is some fundamental difference between “natural” and “man-made” chemicals is a very common misconception, often fueled by marketing campaigns for “chemical-free” products. Nature isn't good and nature isn't bad. It's just the way things are.

Many natural organisms can kill you. Such as natural poisons. What exactly is a poison? Paracelsus made the point in the 16th Century that the dose is the important factor. Some years ago a death occurred due to the overconsumption of carrots. The victim turned orange and died.

Dioxin is a dangerous man-made compound, but it is still a million times less toxic than botulinum. One teaspoon of botulinum could kill a quarter of the world’s population, yet some people choose to inject it in the form of Botox®. The popular non-surgical method of temporarily reducing or eliminating frown lines, forehead creases, crows’ feet near the eyes and thick bands in the neck. The toxin blocks nerve impulses and temporarily paralyzes the muscles that cause wrinkles. This gives the skin a smoother appearance.

There really is no one chemical known as "dioxin." It is a made-up word, fueled by environmentalists and the foolish media. It is the name given to any of a family of 75 compounds called dibenzo-para-dioxins composed of benzene and oxygen atoms.

Nature’s poisons outrank those synthesized by chemists, both in number and in toxicity. Nature is the world’s best chemist: five of the seven most deadly known compounds occur in nature.

Dangerous chemical compounds: (N=natural, S=synthetic)

N - Botulinum toxin
N - Tetanus toxin
N - Diphtheria toxin
S - Dioxin*
N - Muscarine
N - Bufotoxin
S - Sarin

*Dioxin is very controversial. Widely considered a very deadly chemical, fueled by media hysteria, it in fact is only dangerous in high doses. According to Encyclopedia Britannica: "Toxicologists mistakenly concluded from studies on laboratory animals that TCDD (dioxin) was one of the most toxic of all man-made substances… Subsequent research, however, discounted most of these inferences, which were based on the effects of very high doses of TCDD on guinea pigs and other peculiarly susceptible animals. Among humans, the only disease definitely found related to TCDD is chloracne, which develops shortly after exposure to the chemical."

The National Institute of Occupational Safety and Health has evaluated the health of industrial workers exposed to dioxin levels 50 times as high as the exposure received by Vietnam veterans (from dioxin in Agent Orange). These workers have shown no increase in cancer risk.

The bottom line on dioxin is that, like alcohol, it can be dangerous in larger quantities (but it is easier to die from alcohol). Fears of cancer, birth defects and such are not being substantiated in the real world. So while dioxins should be treated with care and professional attention, there is no need for the public to panic every time they hear the word "dioxin."

The Next Ten (Most Deadly) Chemicals:

N - Strychnine
S - Soman
S - Tabun
N - Tubocurarine chloride
N - Rotenone
S - Isoflurophate
S - Parathion
N - Aflatoxin
S - Sodium cyanide
N - Solanine

Vitamin C, or ascorbic acid, is one of the most commonly used preservatives and is an essential nutrient for humans. It occurs naturally in many fruits and vegetables but is not very stable and is often destroyed upon cooking. Vitamin C can be synthesized from glucose in the laboratory and the product is EXACTLY the same as the naturally occurring substance.

Some argue that “Synthetic chemicals bioaccumulate in our bodies.” Well, naturally occurring compounds can accumulate in our bodies too. For example, vitamins A and D are fat-soluble vitamins and can accumulate in fatty tissues. Large excesses of these vitamins can cause death just as an accumulation of some synthetic chemicals can. There is no reason why synthetic compounds should accumulate to a greater extent than naturally occurring ones.

If we didn't have chemical preservatives that would be as great a disaster for our food supply as the loss of all forms of refrigeration.

Natural toxins in food
Natural toxins in food can be just as dangerous as synthetic ones. Garlic, mustard, and horseradish all contain allyl isothiocyanate, which can cause cancer. Barbecued meat contains the carcinogen benzopyrene.

Milk products can be toxic for those who lack the enzyme needed to digest it. Parsley, carrots, and celery are good for you, but nevertheless, they contain myristicin, which in large quantities can cause hallucinations, liver damage, and even death.

We all consume a wide variety of natural toxins in an average week. Since we only consume very small amounts of each of the different toxic compounds at any one time, our livers can process the toxins and they are broken down by a range of metabolic pathways. We are exquisitely designed to cope with a whole variety of substances in small quantities that would be poisonous in larger amounts. It is possible to overdo it and suffer the negative effects of these toxins, but in most cases this is rather difficult. For example, caffeine is toxic, but you would have to drink 85 cups of coffee at one sitting to die from caffeine poisoning.

Examples of this kind illustrate that there is no difference between the negative effects of some synthetic chemicals and those of many of the chemicals that occur naturally in the things we eat. The quantity consumed is a vital factor in the effect produced.

Organic food is NOT better for you. This is a common misconception not borne out by the research evidence. In properly controlled investigations on the same dry weight of organic and non-organic fruit and vegetables, analysis showed the same amounts of vitamins, minerals etc. If all the food in the world was organic, so much manure would be needed that there would need to be three times as many cows.

Poisonous mushrooms are certainly natural, and 32 different mushrooms have been associated with fatalities. And an additional 52 have been identified as containing significant toxins. By far the majority of mushroom poisonings are not fatal, but the majority of fatal poisonings are attributable to the Amanita phalloides mushroom. The most toxic mushrooms contain a clear, odorless, tasteless liquid that looks like water. Just a couple of drops in a drink will kill the victim by miserable death a few weeks later. At one point it was used for chemical warfare.

All parts of the beautiful oleander plant contain poison—several types of poison.

Nicotine is a toxic poison. It's natural and addictive, and some say that it kills 1,000 Americans every day. Nicotine is actually a natural pesticide. Not many people realize that nicotine is also sold commercially in the form of a pesticide.

Nature also produces natural pesticides like opium, cocaine, THC (in marijuana), caffeine, digitalis, etc. Pine trees and citrus tree contain a natural pesticide, terpene, that protects them from pests. Citrus peel oil (it is in frozen orange juice) and it is very potent against fire ants and other insects.

Viruses, bacteria, mycoplasmas, and parasites are all natural. Does this mean small pox is good? Viruses can cause cancer. Natural sunlight (in excess) can cause skin cancer. Other natural chemicals that are toxic and dangerous include venom from snakes, spiders, bees, scorpions.

Cyanides are produced by certain bacteria, fungi, and algae and are found in a number of foods and plants. Cyanide is found, although in small amounts, in lima beans, apple seeds, peaches, mangoes and bitter almonds. There are genuinely hazardous cyanide levels in the kernels of apricots and peaches. Many cyanide-containing compounds are highly toxic, but some are not. When cyanide is in combination with other substances, it is sometimes not toxic.

It is estimated that more than 2,000 plant species contain cyanide, a lot of which are our everyday foods. Cyanide exists in its simplest form in nature as a gas: hydrogen cyanide. Fatal cyanide poisoning from our food is very rare. The amount we ingest with our food is usually very minute and our body can handle it with ease. However unnatural sources of cyanide can be very dangerous, and our bodies may not be able to deal with it. The most dangerous cyanides are hydrogen cyanide and salts derived from it, such as potassium cyanide and sodium cyanide, among others.

Nature lovers should know that Chinese herbal remedies often contain mercury, lead, and arsenic!

Fluoride is a mineral that occurs naturally in most water supplies. Fluoridation is an adjustment of the natural fluoride concentration to increase it to about one part of fluoride to one million parts of water. Fluoride is toxic, but at low levels it is harmless. A potentially fatal dose would be approximately 5 mg. of fluoride per kg. of bodyweight.

Most scientists agree that pesticide residues pose a smaller threat to our health than do naturally occurring substances found even in organically grown food. The Food and Drug Administration estimates that pesticides account for just 0.01 percent of the cancer risk associated with food.

Naturally occurring pesticides (found even in organically grown food) are present in the human diet in concentrations 10,000 times greater than man-made pesticides. The obsession with synthetic pesticides is absurd when you consider that natural pesticides produced by plants to ward off insects or animals, which are proving carcinogenic in lab animal tests just as often as their synthetic counterparts, constitute over 99.99 percent of all the pesticides we eat.

Current procedures to test whether a chemical causes cancer entail exposing animals, usually rats or mice, to massive doses of the chemical, then killing the animals and checking for tumors. But there are major problems with this procedure.

One, animals aren't necessarily the best stand-ins for humans. In fact, 30 percent of the time, a chemical that causes cancer in mice won't do so in rats and vice versa, even though these species are much closer to each other than they are to humans. Also many chemicals that cause cancer in rats and mice do NOT cause cancer in hamsters. Chemicals have very different effects on different animals, even on closely related animals like rats, mice, and hamsters.

For another, the dose given the animals is on average almost 400,000 times the dose that the Environmental Protection Agency tries to protect humans against.

The assumption in the testing is that whatever causes cancer in a few rats out of a few dozen at massive doses will, in a population of hundreds of millions of humans, also cause human cancers, even at much smaller doses.

But this is a flawed theory (generally called "linear" or "no-threshold," or "one molecule" theory). This directly contradicts what is known about chemical poisoning, which says that virtually anything at a high enough dose can kill a person, even if at a low dose it is actually therapeutic or even necessary to life, such as vitamins and salt.

Vitamin A in small doses is necessary for life, while large doses will kill you. Eating a lot of salt-cured meat has been linked to stomach cancer, but no one can live without some salt.

Fifty percent of all synthetic chemicals tested in massive doses on laboratory animals have caused tumors. While 50 percent of synthetic chemicals are carcinogenic, 50 percent of the natural chemicals are also carcinogenic.

Many Americans are focusing on synthetic chemicals that may cause cancer in humans, but are blissfully ignorant of the natural carcinogens. There are over 1,000 natural chemicals in a cup of coffee, only 22 have been tested. Of these, 17 are carcinogens. But don't worry about drinking coffee. The problem isn't the coffee—it's the high-dose animal tests. Too many people ignore the fact that rodent tests have shown natural chemicals to be carcinogenic just as often as synthetic chemicals.

By weight, there is more carcinogen-causing chemicals in a cup of coffee than you are likely to get in synthetic pesticides in a whole year. Yet, the average daily intake in coffee is 1,000 times the tolerance level the EPA allows for synthetic pesticides.

Organic apple juice often contains up to 137 naturally occurring volatile chemicals, of which five have been tested. Two of these five have been found to be carcinogenic in laboratory animals.

Pesticide residues (that are eaten by consumers) are nothing to worry about. However, with farmhands, it's different since their levels of exposure are far greater, and so it is good that we have strict rules of exposure for them and for chemical workers. But I don't think anyone's ever died of residues.

Eliminating essential chemical pesticides will likely increase cancer rates.
Synthetic pesticides have significantly lowered the cost of plant foods, thus making them more available to consumers. Eating more fruits and vegetables is thought to be the best way to lower risks from cancer and heart disease (other than giving up smoking; our vitamins, antioxidants, and fiber come from plants and are important anti-carcinogens). If you eliminate essential synthetic pesticides, you make fruits and vegetables more expensive, which means people will then eat less of them, and more will die of cancer. Huge expenditures of money and effort on tiny hypothetical risks does not improve public health. Rather, it diverts our resources from real human health hazards, and it hurts the economy.

There is a misconception that human exposures to carcinogens and other toxins are nearly all due to synthetic chemicals. On the contrary, the amount of synthetic pesticide residues in plant foods are insignificant compared to the amount of natural pesticides produced by plants themselves. Of all dietary pesticides, 99.99 percent are natural: They are toxins produced by plants to defend themselves against fungi and animal predators. Because each plant produces a different array of toxins, we estimate that on average Americans ingest roughly 5,000 to 10,000 different natural pesticides and their breakdown products. Americans eat an estimated 1,500 milligrams of natural pesticides per person per day, which is about 10,000 times more than they consume of synthetic pesticide residues. By contrast, the FDA found the residues of 200 synthetic chemicals, including the synthetic pesticides thought to be of greatest importance, average only about 0.09 milligram per person per day.

Another misconception is that synthetic toxins pose greater carcinogenic hazards than natural toxins. On the contrary, the proportion of natural chemicals that is carcinogenic when tested in both rats and mice is the same as for synthetic chemicals—roughly half. All chemicals are toxic at some dose, and 99.99 percent of the chemicals we ingest are natural.

And yet another misconception is that the toxicology of man-made chemicals is different from that of natural chemicals. Humans have many general natural defenses that make us well buffered against normal exposures to toxins, both natural and synthetic. DDT is often viewed as the typically dangerous synthetic pesticide. However, it saved millions of lives in the tropics and made obsolete the pesticide lead arsenate, which is even more persistent and toxic, although all natural. While DDT was unusual with respect to bioconcentration, natural pesticides also bioconcentrate if they are fat soluble. Potatoes, for example, naturally contain fat soluble neurotoxins detectable in the bloodstream of all potato eaters. High levels of these neurotoxins have been shown to cause birth defects in rodents.

Carrots contain natural chemicals that have been found to cause cancer in rodents in massive doses. This is also true of apples, bananas, broccoli, Brussels sprouts, cabbage, celery, and many other unprocessed foods. Further testing is likely to eventually find natural rodent carcinogens in essentially everything we eat. We are surrounded by a sea of carcinogens, most of which are natural compounds occurring normally in a variety of foods. The body's defense mechanisms are able to resist these carcinogens in small doses, though often not in the massive amounts which laboratory rodents receive.

Many of those naturally occurring chemicals are themselves pesticides, developed not by industrial chemists but by mother nature. Plants couldn't survive if they weren't filled with toxic chemicals. They don't have immune systems, teeth, claws, and they can't run away. So throughout evolution they've been making newer and nastier pesticides. They're better chemists than Dow or Monsanto. They've been at it a long time. Monsanto, Dow, and Uniroyal are amateurs compared to Mother Nature's pesticide factory.

Potatoes contain two chemicals, solanine and chaconine, which kill insects in the same way that synthetic organophosphate pesticides do. A single potato contains about 15,000 micrograms of these natural pesticides. And yet you're eating only about 15 micrograms of man-made organophosphate pesticides a day.

The typical, newer pesticides use a tablet about the size of an aspirin to treat an acre and is about as toxic to humans and animals as table salt. What they attack are enzymes particular to the pest species. They are not toxic to humans because they are not particular to human systems.

Although charges that eating food with DDT residues caused cancer or even killed humans directly—charges made most prominently in the late Rachel Carson's best-selling 1962 book Silent Spring—later proved to be unsubstantiated, DDT prompted concern that it was causing havoc in the ecosystem because it persisted in the body's tissue and could thus be passed along the food chain.

According to the National Agricultural Chemicals Association, however, none of the pesticides still in use on American crops are persistent.

DDT itself was a tremendous improvement over previous non-synthetic chemical pesticides. It was treated as a miracle chemical when it first appeared and given credit for saving millions of lives, according to the World Health Organization.

But DDT was banned in 1972 before other chemicals were ready to take its place, a ban that some scientists claim shows the damage that anti-pesticide extremism can cause.

The government of Sri Lanka halted the spraying of mosquitoes with DDT. Consequently, the incidence of malaria jumped from nearly zero to 2,500,000 cases and 10,000 deaths before the country began spraying again. Malaria kills! Compare this to known deaths caused by DDT—none. Millions of people were dusted with it and sprayed with it to kill lice and fleas and it never did anyone any harm.

One problem with the environmentalists' argument is their claim that the tiny amount of pesticide residue left on food puts us all at risk of cancer. (About 1 percent of fruits and vegetables have residues above the legal limit; most have none at all.)

This stems from assumptions that a human will react the same way to a chemical as a rodent in a laboratory will. But 30 percent of the chemicals that cause cancer in rats at high doses do not harm mice, and vice-versa. With such a discrepancy between closely related species, what does that say about extrapolating from either of them to humans?

Another questionable assumption is that chemicals that cause tumors in rodents when administered in huge doses will cause tumors in humans at a fraction of those doses. It ignores the scientific axiom "only the dose makes the poison." The iron in a tablet that many adults take regularly has killed babies. Eating a lot of salt-cured meat can increase the risk of stomach cancer, but everyone needs some salt or else they'll die.

It bears repeating that the important rule of toxicology is: The dose makes the poison. If exposure to a chemical is extremely low, then the likelihood of being harmed by the chemical is also low. Some substances that are deadly in large doses may be beneficial in small doses.

Some minerals, such as iron and potassium, are vitally important parts of our diet, but they would poison us if consumed in large quantities. Our bodies naturally contain traces of arsenic and other chemicals that are considered potent carcinogens. The most important factor is the amount of these elements, because that is what determines whether they are beneficial or poisonous. Before you can decide whether toxic chemicals endanger our health, we need to know the level of our exposure to them.

Over 99 percent of the cancer risk associated with food comes from naturally occurring substances in food. Food additives account for approximately 0.2 percent of food-related cancer risks. Pesticides make up 0.01 percent and animal drugs, 0.01 percent.

The cancer risk from pesticides is so low as to be indistinguishable from zero, and is thousands of times less than the cancer risk associated with naturally occurring carcinogens in our diets.

Even though animal tests are not reliable guides for determining risks for humans, you can see in the list below that based on animal tests, the risk factors posed by pesticides and food additives are very low compared to the various foods and drinks we ingest.

Source and daily exposure Risk factor
Wine (1 glass) 4,700.0
Beer (12 ounces) 2,800.0
Cola (1 serving) 2,700.0
Bread (2 slices) 400.0
Basil (1 gram) 100.0
Cooked bacon (100 grams) 9.0
Water (1 liter) 1.0
Additives and pesticides in food 0.5
Additives and pesticides in bread and grain products 0.4
Coffee (1 cup) 0.3


Bruce Ames, "Ranking Possible Carcinogenic Hazards," Science 236 (April 17, 1987), p. 271.