Farming methods are rapidly evolving. New foods and novel ingredients are continuously being introduced into the marketplace. Pesticides and fertilizers are used to increase yields.

Genetic engineering potentially can produce safer, more nutritious, and cheaper forms of foods. Substitutes (such as sugar, fat, and salt substitutes) enable some people to eat foods that would otherwise endanger their health.

However, not everyone would agree that these changes are an advance because many have been accompanied by uncertainty and, in some instances, controversy. What about additives? Organic foods? Irradiated foods? What does it mean when a food is enriched or fortified? Read on.

Pesticides and modern pest management practices have helped to ensure that we have a reliable, affordable, varied, nutritious, and safe food supply. Pesticides are chemicals that kill or prevent the growth of weeds (herbicides), bacteria (disinfectants and antibiotics), molds and fungi (fungicides), and harmful insects (insecticides).

Some pesticides occur naturally in soil, whereas others are found in compounds isolated from particular plants. Many farmers try to control pests in the most effective, least disruptive manner by practicing what is known as integrated pest management.

This approach includes companion planting with plants that contain natural pesticides, crop rotation, use of sterile strains of insects or insect pheromones (to alter reproduction patterns and thereby reduce the insect population), natural insect predators, pest-resistant plant strains, mathematical forecasting techniques, and, when necessary, chemical pesticides.

Should you worry about pesticide residues? The answer is a qualified “no.” The upper limit of the amount of pesticide residue permitted on both raw and processed foods has been carefully established and is enforced by several government agencies. These upper limits are far less than the levels of exposure that are considered harmful.

However, to reduce your exposure to pesticide residues further, you can take the following steps:

• Carefully select the produce you buy (avoid cuts, holes, or signs of decay).

• Thoroughly wash all produce with water (not soap) to remove surface residues.

• Scrub carrots and potatoes and other root vegetables thoroughly. Wash other fresh fruits and vegetables with a brush. Resist the temptation to peel apples, pears, cucumbers, potatoes, and other produce with edible skin, because peeling removes a valuable source of fiber.

• Remove the outer leaves (and any inner leaves that appear to be damaged) from leafy vegetables such as lettuce and cabbage.

• Eat a variety of foods rather than large amounts of a single food.

What About Food Additives?

Contrary to what many of us think, food additives have been used for centuries (and until the past 100 or so years, without much regard for health considerations). Additives play various roles in foods. Some additives act as preservatives, preventing spoilage, loss of flavor, texture, or nutritive value.

These include antioxidants such as vitamin E, BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene), citric acid, and sulfites; calcium propionate; sodium nitrite (which prevents infection by the dangerous bacteria that causes botulism); and other antimicrobials (germ-fighting additives).

Other additives are used as emulsifiers to prevent foods from separating. Emulsifiers include lecithin from soy, egg yolks, or milk and monoglycerides and diglycerides. The leavening agents sodium bicarbonate (baking soda and powder) and yeast allow baked goods to rise.

Stabilizers and thickeners create and maintain an even texture and flavor in foods such as ice cream and pudding. Many foods are also fortified or enriched with vitamins, minerals, or proteins or their component amino acids. The government strictly regulates food additives.

The safety and effectiveness of each newly proposed additive must be rigorously tested. Some 700 additives belong to a group of substances referred to as GRAS substances (Generally Recognized As Safe) because extensive testing and use have shown no evidence of adverse effects.

Continued approval requires that all additives, including GRAS substances, must be reevaluated regularly with the latest scientific methods. According to law, additives and preservatives must be listed on food labels. People who are sensitive to certain additives such as sulfites or monosodium glutamate should be sure to read labels for additive information.

Organic Foods, are they really Better?

If pesticides and food additives pose any potential risk at all, would we be better off eating only “organically grown” foods? What is an organic food? Organic farming methods are those that use only nonsynthetic products (substances that are naturally found in the environment).

Can you be sure that the organic products you buy are really grown and produced organically? In 1998, Congress enacted the Organic Foods Production Act, which regulates production and processing standards for organic foods. This act specifies that foods sold as “organically grown” or “organically processed” must be certified by the U.S. Department of Agriculture.

However, organically produced foods may not be 100 percent organic. By law, they must have at least 50 percent of their ingredients produced naturally, and organically processed foods must contain at least 95 percent organically produced ingredients. Are these foods better?

Not necessarily. Nutritionally, organically grown foods may not be significantly different from the same products grown with conventional farming techniques. The nutrient content of a product is determined by many factors, including the composition of the soil, the genetic makeup of the plant, the degree of maturity at harvest, and methods of handling after harvest.

The taste of organic products may or may not differ from that of conventionally grown foods. Organic methods tend to be more costly (in terms of both labor and materials), production is lower, and consumer prices tend to be higher.

In addition, organic methods are not always safer. Some pesticides reduce the risk of exposure to certain harmful organisms that represent a much greater potential risk than does exposure to the pesticide. In most instances, personal preference rather then proven benefit determines whether you choose to eat an organic food.

What About Irradiated Foods?

Until the 1800s, soaking in salt and natural fermentation were the most commonly used methods for food preservation. This changed with the introduction of canning in the 1800s. Pasteurization began to be used in the late 1800s to kill harmful bacteria, freezing in the early 1900s to extend the shelf life of foods, and freeze drying in the 1960s to preserve foods.

Food is irradiated when it is passed through a beam of radiant energy. Irradiated foods are not radioactive. Irradiation does not diminish the importance of safe food handling, nor does it improve the quality of food.

However, irradiation can extend the shelf life, reduce food wastage, and reduce food prices. Most importantly, irradiation can destroy bacteria that cause foodborne illness.

Food irradiation is strictly controlled by the Food and Drug Administration (FDA). All irradiated foods carry a symbol and the phrase “Treated by Irradiation.” However, when irradiated foods are used in a restaurant, they are not required to be labeled.

What About Genetically Engineered Foods?

Modern genetic-engineering techniques are a refinement of traditional plant-breeding methods. Genetic engineers first select a desired plant trait. They then isolate and modify the gene(s) responsible for the trait. Finally, they attempt to introduce the altered gene into other plants.

In essence, genetic engineering accelerates the natural mixing of genes that normally would occur among various plant species. Genetic engineering of plants has yielded several benefits. Farmers can protect crops against weeds with genetically engineered biodegradable herbicides that need fewer applications.

Genetic engineering also can extend the time before spoilage begins, enabling growers to harvest foods closer to peak freshness. Crops can be genetically engineered to be drought- and temperature-resistant.

Genetic engineering can increase crop yields and enable plants to tolerate a wider range of climates. Genetic engineering also can increase the amount and quality of protein in beans and in grains such as rice.

Although there are benefits associated with genetically engineered foods, there also are lingering questions about the long-term effects on the environment and the ability of producers and the government to ensure the safety of the process. Therefore, the debate continues regarding how genetically engineered foods should be developed and regulated.

What Do the Terms “Fortified” and “Enriched” Mean?

Do you know the difference between the terms “fortified” and “enriched”? Both words indicate that nutrients have been added to the food. Fortified means that nutrients were added that were not there originally. Enriched means that nutrients lost during processing are replaced.

Fortified and enriched foods have helped eliminate many oncecommon nutritional deficiency diseases. Salt was the first commercial food item in the United States to be fortified with additional nutrients. Since 1924, potassium iodide has been added to table salt to help prevent goiter (an enlarged thyroid that may result from iodine deficiency).

Vitamin D was first added to milk in 1933. Rickets, a deforming bone disease, can result from too little vitamin D. Rickets was very common during the early part of the century when working children were deprived of nutritious diets and sunlight.

Flour, and products made with flour, were first fortified with vitamins and iron in 1940 at the start of World War II. The goal was to build strong, healthy armies by feeding troops well-fortified diets. Most breakfast cereals are fortified to provide about 25 percent of most daily nutrients.

Many of these vitamins may dissolve into the milk that you pour over the cereal, so it is important to drink the milk at the bottom of the bowl. (Plus, milk itself provides its own nutrients.)

Most recently, folic acid has joined the list of fortifiers added to grain-based (bread, cereal, pasta, rice) foods to help meet nutrient needs and to reduce the incidence of birth defects and possibly the risk of heart disease.