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Engineered for Controversy

Putting genetically engineered foods under the microscope.

WebMD Feature

Depending on whom you listen to, genetically modified foods are either an environmental catastrophe waiting to happen or the salvation of the world. Critics warn that tinkering with genes could introduce toxins and other harmful chemicals into our food supply. Proponents say biotechnology will create more healthful fruits and vegetables and reduce our dependence on pesticides and herbicides.

There isn't an easy answer. While the potential benefits of genetic engineering can seem alluring, some experts think those benefits may not be worth the risk.

Making Healthful Foods Even More Nutritious

Imagine an orange that contains all the nutrients found in a multivitamin. Or a tomato brimming with high levels of potent cancer-fighting substances. How about a handful of nuts with less saturated oil and none of the allergy-provoking substances that prevent many people from enjoying foods like cashews or almonds?

Welcome to the brave new world of agricultural biotechnology, where scientists are using the latest genetic engineering tools to create foods unlike any seen before. For centuries farmers have created new varieties of fruits and vegetables by crossbreeding plants with desired traits. The difference today is that genetic engineering vastly speeds up the process and gives scientists exquisite precision.

Researchers can identify a single specific gene responsible for a particular trait -- the gene that gives tomatoes their sweetness, for instance -- and then snip it out of one variety and splice it into another. They can even mix and match genes from wholly different plants, taking a gene from berries and splicing it into a watermelon seed, for example. Some researchers are even introducing animal genes into plants -- and vice versa.

"Genetic engineering holds out the promise of making many foods that are already good for you even better," says Clare Hasler, who directs the functional foods program at the University of Illinois. "Tomatoes are being engineered to produce more lycopene, an antioxidant that may reduce cancer risk. Beans are being engineered to have less of the carbohydrates that produce gas. There are efforts under way to produce better broccoli, with more cancer-fighting chemicals than conventional varieties, and soybeans with higher levels of isoflavones, substances that can help lower heart disease risk."

Monsanto Corporation is producing a potato with higher starch content that will absorb less oil during processing -- making better-tasting and healthier french fries, the company claims. Another biotech company is developing sweet peppers modified to be even sweeter and tastier, thanks to alterations in the gene for sweetness.

Plants aren't the only focus of genetic engineering. A company called AquaAdvantage plans to market salmon, trout, flounder, and tilapia that have been modified to grow from egg to market size in half the time they normally require.

Reducing the Need for Toxic Chemicals

So far the biggest push has been to create crops that are easier to grow. Varieties of corn, cotton, rapeseed, and tomatoes have been given genes that make them resistant to commonly used pesticides and herbicides, which means farmers can control weeds and bugs without threatening the crop. Already, 20 to 45% of American corn and soybeans are grown from seed engineered to produce its own bug-killing substances. The U.S. Department of Agriculture recently approved a variety of squash that is resistant to a plant virus that has been known to wipe out whole fields.

"Biotechnology has already led to an 80% reduction in insecticide use in U.S. cotton crops," says Amy Ridenour, Director of the National Center for Public Policy Research in Washington, D.C.

Plants can also be engineered to require less irrigation, reducing the demand for water. By increasing the yield of plants, proponents say, gene manipulation could help feed the earth's burgeoning population in years to come. According to a 1997 report from the World Bank, biotechnology will increase food production in the developing world by 25%.

Growing Fears Over Potential Dangers

Why, then, has genetic engineering sparked such furious opposition?

"One concern is that altered foods could cause susceptible people to become allergic to foods they previously could safely consume," says Rebecca Goldburg, Senior Scientist at the Environmental Defense Fund.

Another worry is that crops engineered to be resistant to insects and even pesticides could become "superweeds," wiping out other varieties and taking over the landscape.

No one yet knows how serious such risks may be. But fears on the part of consumers may already be knocking the wind out of what many experts thought would be another green revolution. "Two years ago we thought genetically engineered foods would be the next big thing," Hasler says. "Now even biotech companies are beginning to wonder if consumers will accept these foods."

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Last Editorial Review: 1/30/2005 10:39:46 PM




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