According to the Institute of Food Technologies (IFT) at Rutgers University:
Surveys indicate that many consumers purchase organic foods because of the perceived health and nutrition benefits of organic products. In one survey, the main reasons consumers purchased organic foods were for the avoidance of pesticides (70%), for freshness (68%), for health and nutrition (67%), and to avoid genetically modified foods (55%) (Whole Foods Market 2005). Such consumers appear to be willing to pay the typical 10% to 40% price premium that organic products command.
There are even more benefits to consuming organic food than avoidance to toxic chemicals: organic food is actually more nutritious the conventionally grown food.
The classic symptom of the standard American diet (SAD) is being overfed but undernourished. How does this happen? Not only our processed foods devoid of essential vitamins and minerals due to their lack of freshness and chemical process, but even the conventionally grown fruits and vegetables lack the same mineral content as their organic counterparts.
In recent years, researchers have conducted several controlled studies to compare organic and conventional foods with respect to
nutritionalcomposition(Table2).Somestudieshaveconcludedthat organic production methods lead to increases in nutrients, partic- ularly organic acids and polyphenolic compounds, many of which are considered to have potential human health benefits as antiox- idants. However, other studies did not demonstrate differences in nutrients between organic and conventional production methods.
Two major hypotheses explaining the possible increases in or- ganic acids and polyphenolics in organic versus conventional foods have been proposed. One hypothesis considers the impacts of differ- ent fertilization practices on plant metabolism. In conventional agri- culture, synthetic fertilizers frequently make nitrogen more avail- able for the plants than do the organic fertilizers and may accelerate plant growth and development. Therefore, plant resources are allo- cated for growth purposes, resulting in a decrease in the production of plant secondary metabolites (compounds not essential to the life of the plant) such as organic acids, polyphenolics, chlorophyll, and amino acids.
The second hypothesis considers the responses of plants to stressful environments such as attacks from insects, weeds, and plant pathogens. It has been argued that organic production methods—which are limited in the use of insecticides, herbicides, and fungicides to control plant pests—may put greater stresses on plants and may require plants to devote greater resources toward the synthesis of their own chemical defense mechanisms. Increases in antioxidants such as plant polyphenolics have been attributed to their production in plant defense (Asami and others 2003), al- though the same mechanisms may result in the elevations of other plant secondary metabolites that may be of toxicological rather than nutritional significance.
While the 2 hypotheses may explain the potential increases in nu- tritional compounds in organic foods relative to conventional foods, as seen in a few studies, the impact on human health of consuming greater levels of organic acids and polyphenolics has yet to be de- termined. Studies using organically and conventionally cultivated strawberries demonstrated that extracts from organic strawberries showed higher antiproliferative activity against colon cancer and breast cancer cells than did extracts from conventional strawber- ries (Olsson and others 2006). While these results suggest a possi- ble mechanism by which organic foods could reduce human cancer risks compared with conventional foods, such results were obtained from in vitro studies and not from human or rodent feeding stud- ies. One in vivo feeding study failed to demonstrate any differences in plasma levels of the antioxidants vitamin C and lycopene in hu- man subjects who had consumed tomato purees from either or- ganic or conventional sources for 3 wk. This study did find that organic tomatoes showed higher vitamin C levels and that organic tomato purees showed higher levels of vitamin C and polyphenols than did conventional tomatoes and purees (Caris-Veyrat and others 2004).
While nutritional comparisons of organic and conventional foods provide quite variable data when considering the possible differ- ences in plant secondary metabolites and minerals, it appears that organic production of foods does result in lower nitrate levels.
The authors are careful to conclude that: “it is premature to conclude that either food system is superior to the other with respect to safety or nutritional composition;” however, there is enough information for me.
It’s interesting when you start researching a story and find that your original lead may be a bit misleading. This story began with the following image shared on Facebook.
When researching Rutger’s work on organic vs. conventional, I found the above work by the IFT that I quoted a large portion of above (sorry, it just all seemed important). When looking for Firman E. Bear’s research, I came across the following:
One study that’s often mentioned in the organic vs. conventional debate is the Firman E. Bear report. This report DID NOT look at the nutritional differences between organic and conventionally raised produce, though the popular press has incorrectly portrayed it in this manner for many years. The study, published in a 1948 edition ofProceedings of the Soil Science Society of America (7), examined the mineral composition of vegetables grown in different regions and on different soil types. Part of the more recent confusion may stem from the way the results were presented; i.e., organic and inorganic soil types rather than organic and conventional production methods.
Dr. Bear and his colleagues found that vegetables grown on heavy soils in the Ohio Valley had a greater mineral content than produce grown on sandy Coastal Plain soils near the East Coast. Interestingly, fertilizer rates on farms in the coastal-plain states were much higher in contrast to fertilizer rates used on farms in east north-central states. Clover sods and manures were more prevalent in the east north-central region. These results are important in themselves because they show that soil type (and quite likely differences in clay mineralogy, soil organic matter, and biological soil activity) affect the mineral composition of foods grown on them. In general, they found that trace element and mineral content increases from south to north, and from east to west. Overall, mineral composition is affected by geography, climate, and fertilizing practices.
I agree the issue of organic vs. conventional is complex as to why the produce does typically have higher nutritional content. Soil quality, including depletion from overfarming, is just as important. Organic and biodynamic practices do more to replenish soil, as they rely on it more heavily than conventional farming and its petrochemical fertilizers and pesticides. It is all related.
The original debate on organic vs. conventional nutritional quality began with the following study:
Indirect evidence supporting this argument comes from the recent work of Davis and others (2004), who compared USDA nutrient content data for 43 garden crops between 1950 (before many modern methods of agricultural production had achieved widespread adoption) and 1999. Statistically reliable de- clines were noted for 6 nutrients (protein, calcium, potassium, iron, riboflavin, and ascorbic acid), with declines ranging from 6% for protein to 38% for riboflavin. However, Davis and others attributed the decreases in nutrient content to changes in the cultivars (plant varieties) used. They maintained that cultivars are frequently selected for their yield characteristics, growth rate, and pest resistance but are not chosen because of their nutrient content.
I believe organic farmers are more concerned about preserving heirloom varieties, offering consumers choice, and providing superior produce than criteria used by conventional farmers when selecting seeds. If you have ever read an Epitaph for a Peach, you know about the struggles family organic farmers face to market food that needs to be sold when ripe, spoils easily, but has the best flavor.
One thing all researchers seem to agree on is that organic produce does have lower pesticide residue.