By McKenzie hall // Environmental Nutrition newsletter

The organic industry is hot; the fastest growing sector of the supermarket grew sixfold from 1997 to 2011, when it accounted for $24.4 billion in sales. ¶ Organic food talk has received even more attention since a study released from Stanford University last year concluded there isn’t much difference between organic and conventional foods. ¶ The study set off a firestorm of dialogue among both consumers and nutrition professionals, as they discussed a larger meaning of whether choosing organic foods is the best strategy for your health, as well as for the environment.

Stanford researchers reviewed a collection of about 240 previously published studies, developing a statistical compilation of these findings. The studies they examined were performed over multiple years and took into account the nutrient and bacterial, fungal or pesticide contamination levels in various foods, such as fruits, vegetables, grains, meats, milk, poultry and eggs, as well as its impact on humans.

For most vitamins and minerals, no significant difference between organic and conventional produce was found in nutrient content, with the exception of phosphorous, which was higher in organically grown varieties. Yet, researchers did find organic produce to have a 30 percent lower risk of pesticide contamination, and organically farmed chicken and pork to have lower levels of antibiotic-resistant bacteria.

Despite these findings, other studies have documented health and environmental advantages of organic foods compared to their conventional counterparts. A similar analysis of studies conducted by researchers at Newcastle University in England found higher levels of vitamin C and phenols – plant antioxidants – in organically grown crops.

In a study published last year in the Journal of Agricultural and Food Chemistry, which examined the effects of organic and conventional cropping systems for spinach, researchers found the organic variety to have higher levels of certain flavonoids and vitamin C.

All organic foods are not the same, according to the Environmental Working Group, a nonprofit organization involved in public health research. For the last nine years, the group ( has identified the “Dirty Dozen” non-organic foods with the highest pesticide load and the “Clean 15” foods with the lowest load.

One of the main attractions for eating organic goes beyond increased nutrient content to lowering one’s exposure to pesticide residues.

“Don’t buy organics to increase phytochemical intake, but because organics generally have lower levels of pesticides,” urged Alyson Mitchell, professor and food chemist at the University of California-Davis.

According to this year’s “Shopper’s Guide to Pesticides in Produce,” the group’s latest Dirty Dozen includes:

• Apples, celery, cherries, tomatoes, cucumbers, grapes, hot peppers, imported nectarines, peaches, potatoes, spinach, strawberries and sweet bell peppers – 13 in all. The group also advises awareness when buying collard greens, summer squash, zucchini and kale, the latter two of which the organization cites as special pesticide level concerns.

The Clean 15 includes:

• Asparagus, avocado, cabbage, cantaloupe, corn, eggplant, grapefruit, kiwi, mangos, mushrooms, onions, papayas, pineapples, frozen sweet peas and sweet potatoes.

“If people are making the choice to buy organic, it’s a good reference,” said Heather Lazickas, promotions and education coordinator with the Lexington Co-Operative Market on Elmwood Avenue.

The organic food movement also takes into consideration how agricultural practices affect the environment. The Rodale Institute’s Farming Systems Trial is the longest-running U.S. study to compare conventional and organic agricultural practices. The project found that organic farming uses 45 percent less energy, produces 40 percent less greenhouse gas emissions, and better supports soil organic matter compared to conventional systems.

Additional evidence-based studies indicate organic farming methods create healthy soils, which yield crops that are consistent with, or better than, those grown by conventional agricultural methods.

Sure, organics may have some documented benefits, but are they worth the additional dollars? To help you gauge the price vs. benefit, here’s a look at the average cost-breakdown for three commonly consumed foods:

Apples (per fruit): organic, $2.35; conventional, $1.34

Canned black beans (per 15-ounce can): organic, $1.77; conventional, $1.16

Boneless, skinless chicken breast (per pound): organic, $8.63; conventional, $3.49

Refresh Editor Scott Scanlon contributed to this story.