Organic foods are claimed to be more nutritious, have more flavor, and be more environmentally benign, safer and generally better for the consumer and the environment than are foods grown traditionally. To be labeled "organic," they must now meet standards set by the government.

To meet these standards, among other things, organic foods must be produced using minimal off-farm inputs and management involving the restoration, maintenance and enhancement of ecological harmony. No synthetic pesticides, growth hormones, antibiotics, genetic engineering, chemical fertilizers or sewage sludge can be used in their production. Additives to enhance flavor, texture, shelf-life or color are generally prohibited.

Because of these restrictions and the paperwork involved in proving authenticity of the organic foods, there is an increased cost to the consumer. There is more waste and a shorter shelf-life for organic foods because of the lack of pesticides and preservatives, also increasing the cost.

Despite the higher cost, organic foods have become increasingly popular. They now account for more than 2 percent of all food sales. In 2005, organic food sales were more than $13.8 billion in the United States.

As a chemist, I am skeptical of the label "organic foods." With very few exceptions, such as salt and baking soda, all food is organic. Also, everything is composed of chemicals, belying claims by some that their products are "chemical-free." The only thing that is chemical-free is a perfect vacuum, not particularly nutritious.

Many studies have shown qualitative differences between organic and conventional food. Often, the organic food will not be as brightly colored and will have more blemishes from insects and bacterial attack. No scientific studies, to date, have shown any differences in safety or composition of the food for either organic or conventional food.

Organic fruits and vegetables will have fewer pesticide residues. This might stimulate production of natural toxins produced by the plants when organic crops are subjected to increased pest pressures from insects, weeds or plant diseases.

There might be increased levels of polyphenolic antioxidants in some organic fruits and vegetables. Polyphenols are suspected carcinogens. Organically grown food animals might have higher bacterial contamination as organic production generally prohibits use of antibiotics.

Organic fertilizers have the potential of passing on to the fertilized plants any bacteria or parasites present in the animals producing the manure. This risk would be minimized if the manure is cooked thoroughly, but that is not usually done.

Those with a low income may find that the cost of organically produced foods excessive for their budgets. The choice of food is up to each of us, considering the facts available. I would suggest that, unless money is of no concern, conventional food is the best choice for most.

Much of this information, in more detail, can be found in and article by Carl K. Winter and Sarah F. Davis in the November-December 2006 Journal of Food Science. Many Web sites have a wealth of information. Some are www.looksmart.com, www.cei.org and www.activistcash.com.

Delbert Marshall, Hays, is a member of the Generations Advisory Group