Bethann Hubbard's biggest grocery-shopping question used to be whether generic products offered a better value than name brands for her family of four.

Then last year, StarLink, a strain of laboratory-engineered corn approved only for animal feed, leaked into the human food supply.

Suddenly, Hubbard and others began to worry and wonder about something that most Americans had barely noticed before: genetically engineered foods.

Now the issue polarizes opinions about benefits and risks.

Foes call the products "Frankenfoods," which they say endanger human health and the environment. They worry that genetically engineered foods are an inadequately tested and regulated experiment that could create "superweeds" and "superbugs" and reduce biological plant diversity.

What some fear most is the unknown.

"We have stepped into an area that we don't understand," said Suzanne Wuerthele, a regional toxicologist with the Environmental Protection Agency who specializes in pesticides and consults on genetic engineering issues with the Rocky Mountain chapter of the Sierra Club.

Supporters say fiddling with the genes of plants increases farmers' yields, even offering a way to fight world hunger, while reducing pesticide use. They envision so-called GE foods delivering nutrients, vitamins and even vaccines.

While there are unknowns, advocates say the new crops are monitored and there have been no documented cases of someone being harmed by GE food.

"People have been watching too many B movies," said June Medford, a Colorado State University biologist who has published numerous scientific papers on her plant-genetics research. "This is not the attack of the killer tomatoes."

In Colorado, GE food increasingly is attracting attention in kitchens and grocery aisles, on farms, in the political realm and, possibly, on Denver's ballot this year.

"I read about those taco shells they had to recall, and that worried me a little," Hubbard said, rolling a shopping cart through an east Denver Safeway parking lot.

"I've heard that this food engineering can do some good things, but there are some concerns also. I'm not sure if I'd buy them or not."

Chances are, however, that her grocery bags - and yours - already are filled with GE foods.

About 60 percent of processed foods on grocery shelves contain genetically engineered ingredients, experts say.

Many consumers may not know it, but it's likely that products they buy containing corn, canola and soy come from seeds that have genes inserted to change their characteristics. The engineered genes are widespread in items such as baking mixes, soft drinks, cereals, soups, cooking oils, salad dressings, juices, canned foods, crackers, snacks and baby food.

GE foes in Denver seek ballot initiative

Engineered traits also have popped up where they're not supposed to be. In the case of StarLink, farmers and others couldn't keep the GE corn segregated. Organic farmers and others who don't want to grow GE crops say pollen from biotech crops could blow onto their fields. Testing has discovered genetically engineered organisms in many products, including some labeled as being GE-free.

Genetically engineered plants first were grown in test fields 15 years ago and have been on most Americans' tables for six years.

Petitions to ban the sale or distribution of GE foods on school property in Denver will soon be popping up. By summer's end, backers hope to gather the required 2,500 valid signatures needed to get the initiative on the November ballot.

Debate over genetically engineered foods has been heightened by fears in Europe. Skeptics there said they were concerned the safety of GE foods had not been adequately proved. This was before health concerns were heightened by the recent outbreaks of mad cow disease and foot-and-mouth disease, events unrelated to genetic engineering.

In one sense, all crops have been genetically altered. They've been bred and crossbred, both deliberately by humans and by the vagaries of pollination.

What's new is the technological breakthrough that lets researchers create new strains by inserting a gene from another organism - a bacterium, a plant or an animal - into a plant's genetic blueprint.

The idea is to transfer a trait or characteristic, such as taking a common soil bacterium's ability to kill insects and incorporating that into a crop plant's genetic makeup.

Cotton, tobacco, potatoes, corn and soybeans are among the crops transformed through designer genes to battle pests, disease and weeds.

Wheat has been altered to withstand drought and strawberries changed to weather frost. Still other tests aim to bolster plant nutrition, deliver vaccines, slow spoilage and lower fat and cholesterol.

The ability to design new living organisms has created a brave new world of science, ethics, politics, sociology and economics.

"The genie is clearly out of the bottle," said Boulder County Commissioner Paul Danish after the commission unanimously declined in January to ban GE crops on 40 to 60 acres of county open space leased to farmers.

The National Center for Food and Agricultural Policy announced in January that genetically engineered crops accounted for 54 percent of the nation's acreage devoted to soybeans, 19 percent of corn and 2 percent to 3 percent of the potato crop.

In Colorado, a small portion of corn, potato and sugar beet crops are being grown with GE seed, say state officials, who do not track the exact amount. Biotech research is focusing on several other vegetables, fruits and grains. GE wheat, for example, may be available commercially in two to four years.

"You could conclude that just about all crops have transgenic breeding underway," said Jim Quick, a CSU crop researcher.

Does that pose a health risk?

Proponents say no, noting that not one case of illness has been linked with GE foods. They also note the plants and foods are regulated by the EPA, U.S. Department of Agriculture and Food and Drug Administration.

"This is not some kind of witchcraft. This is harnessing nature," said CSU's Quick. "I look at it as a genetic opportunity rather than a genetic risk."

Jim Geist, director of the Colorado Corn Growers Association, said the crops and effects are closely watched by many federal and private agencies.

But opponents note that with other products, harmful effects took years to appear.

"The industry told us for 30 years that DDT was safe and that there was nothing to worry about," said Patrick West, state chairman of the Colorado Natural Law Party, which supports, among other things, organic agricultural practices and mandatory labeling of GE foods. West also heads the Consumer Coalition for Food Labeling.

Some experts, including CSU's Medford, see genetic engineering as a solution to issues as sweeping as hunger by boosting productivity. By 2025, she said, with a projected world population of 9 billion people, "we could have two options: mass starvation or another doubling of food production."

As in any new scientific endeavor, there are some risks, "but I think they are pretty minimal," said Medford, whose research concentrates on Arabidopsis, a small noncommercial plant that is a relative of wild mustard. She blames fears on ignorance or elitism.

"Do we do it safely and carefully? I think we do."

'Why aren't they feeding the world already?'

But others aren't convinced.

"Why aren't they feeding the world already?" said Sister Dorothy Mary Bauer, a member of the Sisters of Loretto religious order based in Denver and part of a group of environmental activists called the Loretto Earth Network.

Bauer objects to GE crops on many fronts and says that because they are more expensive to purchase, they "make it difficult for farmers in developing countries."

There's a similar division of opinion over whether GE crops help the environment by reducing the need for pesticides.

Genetic engineering has cut pesticide use by 3.5 million pounds each year, according to Syngenta Group Co., a producer of genetically engineered seed.

Chemical giant Monsanto, for example, developed Roundup Ready plants, which are bred to withstand the weed-killer Roundup.

Roundup-resistant plants reduce herbicide use because a farmer can spray the herbicide on the field shortly after the crop has emerged, killing off all the weeds. Roundup, generically called glyphosate, is considered less toxic than most herbicides and breaks down quickly.

The alternative is to spray more toxic herbicides that kill specific weeds several times throughout a growing season, supporters of genetic engineering say.

But foes worry that use of Roundup Ready crops will create "superweeds" that acquire the ability to resist herbicides and spread with impunity. Or that insects could become "superbugs" by learning to adapt to pest-resistant plants.

Where does all this leave consumers?

Wary and feeling uninformed about GE foods, according to several national surveys.

Those responding to a May 2000 FDA questionnaire were surprised, and some were even outraged, when they learned how many foods contain GE ingredients.

The same questionnaire revealed consumers overwhelmingly support labels disclosing which products have GE ingredients. But they disliked labels that said: "Caution: This food contains GE ingredients."

Proposals to label GE products, such as is required in the European Union, have been introduced in Congress and 17 states, including Colorado. A labeling bill by state Sen. Ron Tupa, D-Boulder, was shelved in February.

State Agriculture Commissioner Don Ament contends labeling would cast "a cloud" on crops that have been certified by federal agencies.

"We produce the healthiest foods in the world," Ament said. "What we really want to do here is not to spread hysteria about all of these "Fra nkenfoods.'"

But things have gone wrong, despite monitoring by various regulatory agencies.

The best-known example is StarLink corn.

Engineered to repel insects called European corn borers, StarLink corn has not been approved for human consumption out of concern it could cause allergic reactions.

In September, StarLink corn popped up on U.S. grocery shelves in taco shells made by Kraft Foods.

This year on March 8, lab tests found meat-free corn dogs made under Kellogg's Morningstar Farms label - a brand aimed at health-conscious consumers - contained StarLink.

And a month later, StarLink corn seed was found mixed with seed scheduled for planting this spring.

Another fear is that GE foods could increase bacterial resistance to antibiotics, already a growing problem, since antibiotics have been used to test where a plant gene has been transferred.

'Transferring genes should be carefully examined'

The FDA has given two Colorado State University plant scientists, Pat Byrne and Sarah Ward, a half-million dollars to educate the public about GE crops. Building on their team-taught class on genetically engineered plants, the two self-described "neutral experts" have a Web site with verified information.

"Many of us see benefits to this technology," Byrne said, "but we also think that the risks of transferring genes between species should be carefully examined on a case-by-case basis."

On the business side, some experts see a potential for GE crops to fetch lower prices than "natural" food, for which consumers might be willing to pay more. A more likely obstacle is loss of export markets for biotech crops.

For Colorado farmers, that raises questions about whether to plant crops that produce lower yields with high risk from insects and weather, or engineered crops that may be tougher to market.

The debate takes on more sweeping dimensions as well.

"These are spiritual, religious objections, such as we should never play God, that it's tinkering with nature and we shouldn't cross species boundaries," said Gary Comstock, an ethicist at Iowa State University, who once opposed biotech crops.

Comstock said he became a "cautious champion" of GE crops after finding no logic in opponents' arguments that humans shouldn't tamper with genes.

Still, Comstock said, with new technology "we need to be vigilant. We need to hold our regulators' feet to the fire."

Wuerthele, the EPA toxicologist, sees the same grand dimensions to the issue but comes away far more concerned.

"As we release these things in the United States - this country is really gung ho - we find out about problems after they're released," said Wuerthele, whose agency is neutral on biotech plants but has approved her Sierra Club work.

"We do it and learn by our mistakes. That's OK, as long as your mistakes are small and reversible and don't create huge problems. But if you get a mistake that is serious, then you've done something that has opened Pandora's box."

For consumers such as grocery shopper Bethann Hubbard, genetic engineering holds the promise of better foods. But the issue is also tinged with concern.

"I have a few worries from some of the things I've heard." she said. "But basically I just want to do what's best for my family.

"If they can show me there are benefits, then I'll listen."

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