Genetically Modified Food

on Saturday, March 26, 2011

"When a 1999 cyclone in India left millions of people in danger of starvation, some activists denounced relief societies for distributing a nutritious grain meal because it contained genetically modified varieties of corn and soybeans (varieties that had been eaten without apparent harm in the United States).

These activists are also opposed to “golden rice,” a genetically modified variety that could prevent blindness in millions of children in the developing world and alleviate vitamin A deficiency in a quarter of a billion more.

Other activists have vandalized research facilities at which the safety of genetically modified foods is tested and new varieties are developed. For these people, even the possibility that such foods could be safe is unacceptable.

A 2001 report by the European Union reviewed eighty-one research projects conducted over fifteen years and failed to find any new risks to human health or to the environment posed by genetically modified crops. This is no surprise to a biologist. Genetically modified foods are no more dangerous than “natural” foods because they are not fundamentally different from natural foods.

Virtually every animal and vegetable sold in a health-food store has been “genetically modified” for millennia by selective breeding and hybridization. The wild ancestor of carrots was a thin, bitter white root; the ancestor of corn had an inch-long, easily shattered cob with a few small, rock-hard kernels.

Plants are Darwinian creatures with no particular desire to be eaten, so they did not go out of their way to be tasty, healthy, or easy for us to grow and harvest. On the contrary: they did go out of their way to deter us from eating them, by evolving irritants, toxins, and bitter-tasting compounds. So there is nothing especially safe about natural foods. The “natural” method of selective breeding for pest resistance simply increases the concentration of the plant's own poisons; one variety of natural potato had to be withdrawn from the market because it proved to be toxic to people.

Similarly, natural flavors — defined by one food scientist as “a flavor that's been derived with an out-of date technology” — are often chemically indistinguishable from their artificial counterparts, and when they are distinguishable, sometimes the natural flavor is the more dangerous one. When “natural” almond flavor, benzaldehyde, is derived from peach pits, it is accompanied by traces of cyanide; when it is synthesized as an “artificial flavor,” it is not.

A blanket fear of all artificial and genetically modified foods is patently irrational on health grounds, and it could make food more expensive and hence less available to the poor. Where do these specious fears come from?

Partly they arise from the carcinogen-du-jour school of journalism that uncritically reports any study howing elevated cancer rates in rats fed megadoses of chemicals. But partly they come from an intuition about living things that was first identified by the anthropologist James George Frazer in 1890 and has recently been studied in the lab by Paul Rozin, Susan Gelman, Frank Keil, Scott Atran, and other cognitive scientists.

People's intuitive biology begins with the concept of an invisible essence residing in living things, which gives them their form and powers. These essentialist beliefs emerge early in childhood, and in traditional cultures they dominate reasoning about plants and animals.

Often the intuitions serve people well. They allow preschoolers to deduce that a raccoon that looks like a skunk will have raccoon babies, that a seed taken from an apple and planted with flowers in a pot will produce an apple tree, and that an animal's behavior depends on its innards, not on its appearance.

They allow traditional peoples to deduce that different-looking creatures (such as a caterpillar and a butterfly) can belong to the same kind, and they impel them to extract juices and powders from living things and try them as medicines, poisons, and food supplements. They can prevent people from sickening themselves by eating things that have been in contact with infectious substances such as feces, sick people, and rotting meat.

But intuitive essentialism can also lead people into error. Children falsely believe that a child of English-speaking parents will speak English even if brought up in a French-speaking family, and that boys will have short hair and girls will wear dresses even if they are brought up with no other member of their sex from which they can learn those habits.

Traditional peoples believe in sympathetic magic, otherwise known as voodoo. They think similar-looking objects have similar powers, so that a ground-up rhinoceros horn is a cure for erectile dysfunction. And they think that animal parts can transmit their powers to anything they mingle with, so that eating or wearing a part of a fierce animal will make one fierce.

Educated Westerners should not feel too smug. Rozin has shown that we have voodoolike intuitions ourselves. Most Americans won't touch a sterilized cockroach, or even a plastic one, and won't drink juice that the roach has touched for even a fraction of a second. And even Ivy League students believe that you are what you eat. They judge that a tribe that hunts turtles for their meat and wild boar for their bristles will be good swimmers, and that a tribe that hunts turtles for their shells and wild boar for their meat will be tough fighters.

In his history of biology, Ernst Mayr showed that many biologists originally rejected the theory of natural selection because of their belief that a species was a pure type defined by an essence. They could not wrap their minds around the concept that species are populations of variable individuals and that one can blend into another over evolutionary time.

In this context, the fear of genetically modified foods no longer seems so strange: it is simply the standard human intuition that every living thing has an essence. Natural foods are thought to have the pure essence of the plant or animal and to carry with them the rejuvenating powers of the pastoral environment in which they grew. Genetically modified foods, or foods containing artificial additives, are thought of as being deliberately laced with a contaminant tainted by its origins in an acrid laboratory or factory. Arguments that invoke genetics, biochemistry, evolution, and risk analysis are likely to fall on deaf ears when pitted against this deep-rooted way of thinking.

Essentialist intuitions are not the only reason that perceptions of danger can be off the mark. Risk analysts have discovered to their bemusement that people's fears are often way out of line with objective hazards. Many people avoid flying, though car travel is eleven times more dangerous. They fear getting eaten by a shark, though they are four hundred times more likely to drown in their bathtub. They clamor for expensive measures to get chloroform and trichloroethylene out of drinking water, though they are hundreds of times more likely to get cancer from a daily peanut butter sandwich (since peanuts can carry a highly carcinogenic mold).

Some of these risks may be misestimated because they tap into our innate fears of heights, confinement, predation, and poisoning. But even when people are presented with objective information about danger, they may not appreciate it because of the way the mind assesses probabilities.

A statement like “The chance of dying of botulism poisoning in a given year is .000001” is virtually incomprehensible. For one thing, magnitudes with lots of zeroes at the beginning or end are beyond the ken of our number sense. The psychologist Paul Slovic and his colleagues found that people are unmoved by a lecture on the hazards of not wearing a seat belt which mentions that a fatal collision occurs once in every 3.5 million person-trips. But they say they will buckle up when the odds are recalculated to show that their lifetime chance of dying in a collision is one percent."

Quoted from The Blank Slate, by Steven Pinker