由最新一期《内科学纪事》（Annals of Internal Medicine）月刊刊载的一项最新研究表明，尽管有机食品能够普遍减少食用者摄入农药和耐抗生素细菌的风险，就维生素含量和营养成分而言，“有机”与“非有机”差别不大。
史密斯－斯潘格勒及其在美国斯坦福大学和“帕洛阿尔托退休军人事务健康中心”的同事审核了200多份研究报告。这些报告或对比研究食用有机果蔬、谷物、肉类、禽蛋、牛奶和同种类非有机食品者的健康状况，或对比研究两类食品自身的营养成分和受污染程度。
研究人员发现，尽管许多研究报告没有详细说明“有机食品”的定义，但就维生素含量和营养成分而言，有机与非有机食品没有太大差别。
另外，超过三分之一送检非有机食品检测出农药残留，这一比例在有机食品中为7％；有机猪肉和鸡肉携带3种或3种以上耐抗生素细菌的可能性比非有机肉类小33％。
不过，这份报告引起不少人质疑。他们认为，想弄清有机和非有机食品之间潜在的健康和安全差异需更多研究。（生物谷Bioon.com）
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Are Organic Foods Safer or Healthier Than Conventional Alternatives?: A Systematic Review
Crystal Smith-Spangler, MD, MS; Margaret L. Brandeau, PhD; Grace E. Hunter, BA; J. Clay Bavinger, BA; Maren Pearson, BS; Paul J. Eschbach; Vandana Sundaram, MPH; Hau Liu, MD, MS, MBA, MPH; Patricia Schirmer, MD; Christopher Stave, MLS; Ingram Olkin, PhD; and Dena M. Bravata, MD, MS
Background: The health benefits of organic foods are unclear. Purpose: To review evidence comparing the health effects of organic and conventional foods. Data Sources: MEDLINE (January 1966 to May 2011), EMBASE, CAB Direct, Agricola, TOXNET, Cochrane Library (January 1966 to May 2009), and bibliographies of retrieved articles. Study Selection: English-language reports of comparisons of organically and conventionally grown food or of populations consuming these foods. Data Extraction: 2 independent investigators extracted data on methods, health outcomes, and nutrient and contaminant levels. Data Synthesis: 17 studies in humans and 223 studies of nutrient and contaminant levels in foods met inclusion criteria. Only 3 of the human studies examined clinical outcomes, finding no significant differences between populations by food type for allergic outcomes (eczema, wheeze, atopic sensitization) or symptomatic Campylobacter infection. Two studies reported significantly lower urinary pesticide levels among children consuming organic versus conventional diets, but studies of biomarker and nutrient levels in serum, urine, breast milk, and semen in adults did not identify clinically meaningful differences. All estimates of differences in nutrient and contaminant levels in foods were highly heterogeneous except for the estimate for phosphorus; phosphorus levels were significantly higher than in conventional produce, although this difference is not clinically significant. The risk for contamination with detectable pesticide residues was lower among organic than conventional produce (risk difference, 30% [CI, ?37% to ?23%]), but differences in risk for exceeding maximum allowed limits were small. Escherichia coli contamination risk did not differ between organic and conventional produce. Bacterial contamination of retail chicken and pork was common but unrelated to farming method. However, the risk for isolating bacteria resistant to 3 or more antibiotics was higher in conventional than in organic chicken and pork (risk difference, 33% [CI, 21% to 45%]). Limitation: Studies were heterogeneous and limited in number, and publication bias may be present. Conclusion: The published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods. Consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.
