By Elizabeth Weise, USA TODAY: Organic products have no significant nutritional advantage over conventional foods, even though consumers can pay more for them, a new study finds.
The findings suggest that a key reason behind why many people buy organic products — a $28.6 billion market last year — may not be borne out by the science.
The four-year project began when two doctors wondered what advice they should give their families and patients about whether to buy organic or conventional foods.
“It became much larger than we expected,” says Crystal Smith-Spangler, a primary care doctor at Stanford University and lead author on the study appearing Tuesday in the journal Annals of Internal Medicine.
Eventually, 12 researchers looked at 240 studies conducted from 1966 to 2011 covering nutrient and contaminant levels in foods.
Among the findings:
•There were no significant differences in the vitamin content of organic and conventional fruits and vegetables. The studies looked specifically at vitamins A, C and E.
•Detectable pesticide residue was found in 7% of organic produce and 38% of conventional produce. However, only three studies found pesticide residue that exceeded maximum allowed limits in the European Union on organic or conventional produce.
As to how pesticides could be in organic product that must be grown without them by law, Smith-Spangler said it could either be long-lasting, now-banned pesticides in the soil or drift from nearby fields.
•Both organic and conventional foods were at similar risk for bacterial contamination.
A smaller study done in 2009 by Alan Dangour at the London School of Hygiene and Tropical Medicine with a European emphasis reached similar conclusions.