EDITOR'S NOTE: This is the first of two columns about organic fruits and vegetables.

For years, I've been skeptical about the value of eating organic food. However, with organics becoming mainstream, big corporations getting into the act and more people wondering if they should be eating organic, I wanted the answers to a few key questions.

Q. What are organic fruits and vegetables?

A. Only food producers who comply with federal organic rules can call their food "certified organic." The U.S. Department of Agriculture requires that certified organic crops "be produced without pesticides, herbicides, synthetic fertilizers, sewage sludge, bioengineering or ionizing radiation." Farmers must use organic seeds and may not apply "prohibited substances" (i.e., pesticides, synthetic fertilizers) to the land for at least three years before harvest.

Keep in mind, the USDA makes no claims that organic food is safer or more nutritious than conventionally produced food. The term "organic foods" refers to the method used to produce food rather than to the food itself.

You can view all the organic standards at www.ams.usda .gov/nop/NOP/standards/ProdHandReg.html.

Q. Are organic foods more nutritious?

A. It's difficult to make a blanket statement that organic fruits and vegetables are more nutritious. Nevertheless, there is some evidence to say that some specific organic foods are more nutritious.

"On average, organic produce contains marginally higher levels of vitamin C, antioxidants and certain minerals, compared to conventional foods grown under the same soil and climactic conditions," says Charles Benbrook, chief scientist of the Organic Center for Education and Promotion. "For people wanting to prevent disease by increasing their intake of these health-promoting components of food, organic food delivers on average more nutrition per serving and per calorie consumed than does conventional food."

After an extensive review of the scientific literature, he asserts that organics have about one-third more antioxidants. (Read the review: www.organic-center.org/Antioxidant_SSR .pdf.)

One theory explaining the high antioxidant content of organic foods is that the crops need to produce more antioxidants to fight off pests and diseases. Because the plants aren't treated with pesticides, they must work harder to stay healthy, which increases stress and creates a higher level of antioxidants.

But does the higher antioxidant content make a real difference in terms of health?

"Science cannot predict nor necessarily prove that a 30 percent or 80 percent increase in antioxidant or vitamin intake will prevent disease, but strong evidence demonstrates that increased nutrient and antioxidant density of food promotes incremental progress," argues Benbrook.

But "The common belief that, 'If a little is good, more is even better,' has no basis in our understanding of toxicology. Virtually all vitamins and minerals are dangerous if too much is consumed," says Anthony Trewavas, a professor and plant scientist at the Institute of Cell and Molecular Biology in Edinburgh, Scotland.

Most experts agree that increased nutrient content is not necessarily the primary reason to buy organic. According to Urvashi Rangan, an environmental scientist at Consumers Union, "While preliminary evidence does suggest, for example, that an organic orange has four times the antioxidants of a conventionally grown orange — if that's why you're buying them, you may want to wait until there is stronger scientific proof."

Q. Is it true that organic foods taste better?

A. Organic food has a reputation for tasting better. It was mainly available at roadside stands and was fresher than the conventional produce sold in supermarkets, says Joseph Rosen, a professor of food science at Rutgers University in New Jersey; he doesn't believe there is any difference.

Benbrook offers an alternative reason: "Organically grown food tends to grow more slowly and does not reach the size of conventional produce. Conventional fruits and vegetables grow faster, tend to get bigger and yield a bit more per acre, but they do so at the expense of nutrient and antioxidant density. As a result, the taste, flavor and aroma of conventional produce tend to be diluted."

Q. Are there any other reasons to eat organic?

A. One of the most popular arguments in support of organic food is less about the final product and more about the environment. By eliminating petroleum-based fertilizers, organic farms could help reduce soil erosion, climate change and water contamination. And if you are concerned about genetically modified foods, for the most part, you can avoid them by purchasing organic.

Buying organic is an individual decision. "Some people focus on environmental issues; others care about health issues, worker issues, animal issues, cost issues — there are all kinds of value decisions a consumer can make," says Rangan.

Next week's column will address whether you're at risk by eating conventionally grown fruits and vegetables.

Charles Stuart Platkin is a nutrition and public-health advocate. Write to info@thedietdetective.com.