June 16, 2010

UNIT 7: PlantsGenetically Modified Foods — Do Potential Problems Outweigh Benefits?

There is a food fight going on, and you may need to choose a side. Genetically modified (GM) foods have been on the market since the early 1990s, and today most foods in U.S. grocery stores have GM ingredients. But the wide availability of GM food also raises concerns on topics ranging from health to the environment. Should you be worried about eating GM foods?

New Technology, Old Idea

GM plants have genes that have been genetically engineered, or artificially introduced into the plant’s genome. This technology gives plants a new characteristic. For instance, many crop plants are commonly engineered for disease resistance. Some examples of crops that have GM varieties on the market are apples, carrots, corn, cucumbers, potatoes, squash, strawberries, tomatoes, and watermelon.

Genetic engineering is a fairly new process, but plants have been modified through careful breeding for thousands of years. Many people knowledgeable about genetics argue that genetic engineering of crops is just a faster and more precise method of selective breeding.

The Green Revolution

In the 1960s, scientist Norman Borlaug and a team of researchers used cross-breeding techniques to develop a new strain of wheat. The new strain produced two to three times as much wheat as traditional varieties, and resisted many types of insects and diseases. Widely planted, these new varieties changed Mexico from an importer of wheat to an exporter within 20 years. Borlaug and his team began shipping the new strain of wheat to India and Pakistan, and both countries quickly doubled their wheat production. Known as the Green Revolution, this scientific advance improved crop yields drastically worldwide. For his work, Borlaug received the Nobel Prize in 1970. Today, Borlaug and many others view genetic engineering of crops as the next wave of the Green Revolution.

Benefits of GM Crops

One benefit of GM crops is the potential of improved nutrition. For example, half of the world’s population relies on rice as the main part of their diet. Rice lacks vitamin A, however, and vitamin A deficiency can cause blindness and sometimes death. Researchers developed a new strain of rice, called “golden rice.” Unlike regular rice, golden rice is high in vitamin A. Golden rice could prevent millions of deaths of young children in developing countries every year.

Other promising uses of genetic engineering include growing fruits and vegetables that produce vaccines in their tissues. This would make shipment, storage, and administration of medicine easier worldwide.

Some benefits of GM crops are well established. They include benefits to farmers, such as crops that take less time, water, and land to grow, and plants that can withstand drought or cold temperature or that grow in poor soils.

There are also benefits to the environment, such as crops that lessen the need for pesticide, herbicide, or fertilizer applications. Even the consumer benefits with GM produce that stays fresh longer.

Potential Hidden Costs of GM Crops

Not everyone is enthusiastic about genetically modified foods. Opponents argue that it is impossible to predict exactly how the new crops—sometimes called “Frankenfoods”—will affect ecosystems. For example, the bacterial gene Bt is commonly inserted into GM plants. It produces an insecticidal toxin that is harmless to people. But will insects become resistant to Bt? Insect-repelling GM plants may speed the evolution of pesticide-resistant pests.

Another concern is that weeds can become stronger by cross-breeding with GM crops. When herbicideresistant genes are inserted into crop plants, the weeds are easily killed by herbicides while the crops remain unaffected. But pollen from plants can be carried by the wind for long distances, and seeds from GM crops could be accidentally dispersed outside their intended locations, causing the rise of "superweeds."

Unanswered Questions

Genetically modified crops are no longer considered new, but some questions about them remain. Many of the most important research questions concern the long-term effects of GM crops on human health and the environment. Specific questions include:

• Can people absorb the vitamins in genetically modified crops as easily as they absorb the vitamins in other foods?
• Could GM crops, such as those engineered to produce medicines, have adverse effects on wildlife?

UPDATES: Straight from the Headlines

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• Scientists Develop Iron-Rich Rice Plant
• Report Outlines Benefits and Drawbacks of Genetically-Engineered Crops; Looks Toward Future

What Do You Think?

Last updated June 16, 2010 | Comments (8) | Permalink | UNIT 7: Plants