“Fats and oils can be among the healthiest substances in your diet,” says nutritionist Ann Louise Gittleman, PhD, “but only if they’re organic.” Increasingly, a number of researchers are realizing that pesticides are stored in fatty tissue rather than eliminated from the body, and the higher up the food chain you go, the greater the residual pesticide level.

Oils in conventionally grown seeds and nuts can also be “a storehouse of fattening pesticides—we’re not the only life forms to store toxins in fat, so look for the organic label,” advises Dr. Gittleman. Like other nationally certified foods, organic oils are produced without toxic and persistent pesticides, making them clearly preferable to pesticide-laden fats.

Quality Production

Organic farmers rotate crops, which naturally mixes nitrogen in soil. This “full-circle farming” promotes the most nutrient-dense growing conditions. “Conventional farming ‘treats’ its soil, many times unnaturally,” explains Bruce Barlean, owner of Barlean’s Organic Oils. Adds Ellen Markham at Spectrum Organic Oils, “Organic farming practices such as crop rotation, organic composting, and other traditional methods help to conserve water and soil, protecting the land for future use, and protecting consumers from chemicals and harmful toxins.”

Certified Benefits

Not only are the soils on organic farms far less likely to contain undesirable toxins, but organic certification also tracks the entire process from seed through distillation and manufacture. “Organic oil producers are able to trace the seed growing from its beginning,” says Barlean’s marketing director Andreas Koch. That’s one reason why “organic standards guarantee quality.”

“Organic oils are also guaranteed to be produced from seed that has not been genetically engineered,” adds Spectrum’s Markham. “Corn, soy, and canola are the three most commonly genetically engineered crops for cooking oils. Unless you are buying organic oils, which are prohibited from using genetically engineered seed, you cannot be assured that your oil will be GE-free.” For example, organic soybeans can be expeller pressed and refined to produce a versatile oil for baking and cooking. But three-quarters of conventional soybeans in the United States are genetically engineered, and current food regulations do not require GE labeling.

Solvent and Trans-Fat Free

“Seeds [used by organic oil manufacturers] do not contain any solvents,” says Barlean’s Koch. “Organic oils are expeller or cold pressed—never extracted with chemical solvents—and are minimally processed with no added preservatives,” explains Markham. “These oils are never hydrogenated or partially hydrogenated, a process that creates trans [manufactured] fats,” which have been found detrimental to health. In 2006 the U.S. Food and Drug Administration mandated that food manufacturers list the amount of these hazardous fats on their labels.

Look for a variety of organic oils—from coconut and flaxseed to olive, palm (naturally hydrogenated without trans fat), walnut, and other healthy oils—at your local grocery or health food store.