From The September 2001 Issue of Nutrition Science News

Organic Food Is More Nutritious

For years, organic food proponents have suspected that organic food is higher in minerals and vitamins than conventionally farmed produce. As part of her doctoral dissertation, Virginia Worthington, Ph.D., of Johns Hopkins University, Baltimore, reviewed available research comparing the nutritional value of organically grown and conventionally grown produce. She concluded that organic produce is nutritionally superior.

Worthington collated measurements comparing the composition of vegetables grown simultaneously under different farming conditions. She conducted 41 studies with 1,240 comparisons of 35 vitamins and minerals.

Organically grown produce was higher in most minerals and vitamins and lower in potentially harmful nitrates, which result from nitrogen fertilizers. The greatest differences among all vegetables tested were in magnesium (organic was 29 percent higher), vitamin C (27 percent higher), and iron (21 percent higher). In fact, organic food had higher amounts of all minerals tested, although the difference was not always statistically significant because of small sample numbers. Organic crops had 15 percent fewer nitrates than conventionally grown foods and appeared to also have lesser amounts of toxic heavy metals.

Worthington also investigated the effect of routine consumption of organically grown fruits and vegetables on the nutritional adequacy of the overall diet. Using the USDA recommendation of five servings of fruits and vegetables a day, she determined that consuming organically grown produce might make the difference between a deficient and an adequate diet. She calculated that those who consume organic produce would take in an average of 89 mg vitamin C daily compared with 70 mg for conventional eaters, 3.7 mg iron compared with 3.0 mg, and 80 mg magnesium compared with 68.6 mg.

Nutritional composition of conventionally grown American food has declined during the past 60 years. Iron is lower by 32 percent, calcium by 29 percent, magnesium by 21 percent, and potassium by 6 percent. Organic farming may help reverse this trend.

—The Journal of Alternative and Complementary Medicine 2001;7(2):161.