In Genesis, Jacob asks his father-in-law, Laban, to compensate him for 14 years of unpaid labor. His request is strange: all the speckled and spotted goats and all the dark sheep from Laban’s flock—the least desirable animals. Jacob then peels back the bark of tree branches, making stripes, and places these rods in the animals’ water troughs. According to the story, the sight of the rods make the animals mate, and soon, Jacob’s flock is more robust than Laban’s. Jacob may not have known it, but genes were behind this success: By selectively mating the animals, he brought out genes that would produce desirable traits.
This tale is the first time Jews weighed in on the issue of genetic manipulation, but millennia later, the issue is still a topic of debate. Today, the discussion focuses not on breeding, but on genetically modified organisms, or GMOs, plants and animals whose DNA has been explicitly altered by humans. Genetic engineering is a more high-tech way to bring out specific traits; scientists can now add, delete or adjust genetic material by using “gene guns” to shoot microscopic bullets coated with DNA into living cells. This tactic allows vastly different species that could not breed in nature—including those from the animal and plant kingdoms—to mix genetic material.
The first genetically modified foods to go on the market in the 1980s were typically crops designed by chemical companies to resist herbicides and pesticides. Now the U.S. Department of Agriculture says that the majority of America’s corn and soybeans—primary ingredients in most processed foods, from breakfast cereal to soda, as well as in animal feed—are genetically modified. Some researchers estimate that 70 percent of all processed foods contain some genetically modified ingredients.
Since food is a matter of law and ethics in Judaism, these laboratory creations raise an important question: are genetically modified foods permissible? One aspect of this is whether they are kosher. Because many genetically modified foods are transgenic—or contain the DNA of another organism—fears have arisen that the DNA of pigs may be implanted into otherwise acceptable foods. Does the addition of pig DNA make an organism treif?
The Orthodox Union has a simple answer: Genetically modified foods are kosher. Its reasoning is that the laws of kashrut do not operate on a molecular level; pig DNA is too small to alter a food’s legal status. The Conservative movement’s Committee on Jewish Law and Standards of the Rabbinical Assembly also defends the kosher label of genetically modified food, and draws an analogy to organ transplants. Under Jewish law, transplanted organs that function properly become part of the host. As with a pig’s heart valve that is inserted into a human body, the pig’s DNA loses its “pigness” once it successfully enters a new organism.
Another potential dilemma is combining the DNA of different organisms. While the Bible does not mention genetic modification explicitly, the books of Leviticus and Deuteronomy prohibit kilayim, or forbidden mixtures, particularly in agriculture. In Leviticus, God instructs: “You shall not let your cattle mate with a different kind; you shall not sow your field with two kinds of seed; you shall not put on cloth from a mixture of two different kinds of material.” The reasoning behind this verse, writes 13th-century scholar Nahmanides, is to protect the species that God created, as well as their ability to procreate.
Some have interpreted these passages as a ban on genetic modification, but Michael Broyde, an Orthodox rabbi and senior fellow at the Center for the Study of Law and Religion at Emory University, says the laws of kilayimare not meant to be applied broadly. “A person who comes along and says, ‘What’s really going on here [in these verses] is genetic intermixing, and that’s what’s prohibited,’ would have an enormous burden, which that person couldn’t meet as a matter of substantive Jewish law,” he says. The Conservative movement adds that the laws ofkilayim are designed specifically for Jews, not Gentiles, and that they apply only to the action of mixing, not to its product. “Maybe we shouldn’t be the people to do it, but we can eat [genetically modified foods],” says Northwestern University Professor of Medical Humanities and Bioethics Laurie Zoloth.
None of this, however, should be mistaken for an endorsement, says Broyde, who explains that genetically modified foods “might turn out to be a bad idea.” Since Judaism bans engaging in dangerous activity and the safety of genetically modified foods has yet to be conclusively determined, “they might even turn out to be prohibited.”
Whether they are safe or not is a subject of contention. In the early 1990s, the U.S. Food and Drug Administration ruled that genetically modified foods are “generally recognized as safe” and exempt from many of the regulations that apply to other foods, even though no safety testing has been conducted. In fact, the FDA does not even require foods to be labeled as genetically modified.
“GMOs are essentially an experiment on the human population,” says Zelig Golden, head of the group Wilderness Torah and former attorney for the Center for Food Safety, which filed a lawsuit against the government for its approval of genetically modified alfalfa. “There are no human health studies that truly attempt to discover or prove that they are safe. GMO crops have only been eaten in America for 16 years now, so we haven’t seen one generation who’s grown up eating them.” Other groups such as the Coalition on the Environment and Jewish Life have also called for safety testing.
Some scientists say that genetically modified organisms threaten biodiversity—the variety of plants and animals that live in a particular ecosystem—and encourage agricultural dependence on toxic chemicals. “We humans are not given permission to mess with the fundamental building blocks of life,” says Golden. “In the case of genetic modification, those genetics are not designed to go together, so we’re tinkering at the genetic level with God’s creation.”
Not everyone thinks GMOs are harmful. Advocates says genetic engineering is the only way to keep up with worldwide demand for food. Northwestern’s Zoloth adds that she sees no contradiction between genetically modified food and Judaism. “Judaism is based on an agricultural foundation, and is strongly in favor of seeing animals and plants as things that ought to be modified for human use and for human benefit,” she says. “There’s no moral objection to manipulating nature and using the most sophisticated technology available. It’s not like how the genes happen to be arranged in a particular plant or animal has any divinity to them.”
Nature, Zoloth says, is morally neutral; it can be used for good or for evil. So instead of discarding genetic modification entirely, she hopes it can be used to benefit humanity: “The concern [of the Jewish texts] is how do you make the world in such a way that it’s more just, that no one’s starving, that widows and orphans are cared for, and that everyone can glean without harm. And genetic engineering fits well with that vision of food.”