More nutritious: Food produced under organic conditions are somehow structurally different from chemically-raised and processed products. This pro-organic claim is so far beyond the scope of modern science to prove or disprove. The complex make-up of food, the effect of growing and processing methods, and the internal interactions between people and their nutrients are largely unknown. Measurements of some food components — protein, carbohydrates, fat, vitamins and minerals, and so on — only account for the most obvious factors that have been identified so far, and research is minimal. However, there are scientific indications that, by favoring certain aspects of a plant's development, other aspects may be retarded, resulting in less nutritious food. A study published in the Journal of the American College of Nutrition in 2004, entitled Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999, compared nutritional analysis of vegetables done in 1950 and in 1999, and found substantial decreases in six of 13 nutrients examined. Percentage reductions included 6% of protein and 38% of riboflavin. Reductions in calcium, phosphorus, iron and ascorbic acid were also found. The study, conducted at the Biochemical Institute, University of Texas, concluded that the most likely cause was the breeding of crops to maximize yield. Although not on the surface a strictly organic issue, plant breeding objectives for commercial production is completely integrated with industrialized, chemical-based farming.
Non-toxic: Organic proponents point to potential problems with toxic residues from agricultural chemicals like pesticides. There is no argument that traces do not exist; however, it is widely held that: (a) they are well in "safe" limits (as established by government regulations); (b) washing and other recommended preparation methods eliminate any risk. One potentially relevant new areas is the principle of hormesis, an emerging outlook on the extreme low level effects of substances, that might suggest that exposure to minute quantities of toxic residues on foods may have as specific effects on humans.
Better for the environment: By this argument, every food purchase supports the system that delivers it: if the large-scale chemical production methods are damaging to the environment, then people who buy these products are directly contributing to the problem. A recent UK study concluded that local food is best for the environment, and recommended food produced within a few miles radius as being the most advantageious. Insofar as organic food is often imported from long distances, local organics would seem environmentally to be the better bet.
None of these claims are widely accepted as scientific fact although it seems to be difficult to make the argument that foods grown with chemicals/pesticides are better than those without. There are research reports, expert opinions, and anecdotal evidence both supporting and rebutting them. Learning more about these debates leads to clearer understanding of organic food, and its potential value.
To the consumer looking for self-education, a basic awareness of recent food history provides a useful context. Chemical agriculture and mass production of supermarket food have only been big business for about 50 years. During that period, radical changes in the way food is produced have been justified by quoting scientific studies and conducting large-scale advertising and publicity campaigns. In recent years, the negative longer-term effects of many chemical agriculture practices have become increasingly hard to deny, however, the lack of balanced agricultural and food research is still overwhelming. It is unlikely that anything near definitive scientific conclusions will be drawn for years, possibly decades. In the meantime, consumers have to either trust the existing standards and claims, or come to their own common sense conclusions.