Is organic food always healthier? Maybe not, according to a recent study led by Stanford University researchers.

The study didn’t find strong evidence that organic foods are more nutritious or healthier than foods produced by conventional methods. Plus, the research showed that both organic and non-organic foods shared a similar risk of contamination with bacteria, such as E. coli.

These findings are surprising, considering that a 2007 Harris poll showed that 30 percent of Americans buy organic food at least on occasion … and most think it is safer, better for the environment and healthier.

But the results might not be black and white. Although the Stanford researchers found little difference in nutritional content, they did find that organic produce was 30 percent less likely to have pesticide residue than conventionally grown fruits and vegetables. That makes sense since organic foods, which can cost twice as much as non-organic varieties, are grown using natural-based fertilizers and products.

And although both organic and conventional meats were equally likely to be contaminated with bacteria, organic chicken and pork were 33 percent less likely than conventional livestock to harbor antibiotic-resistant bacteria.

Researchers also reported that organic milk and chicken contained higher levels of omega-3 fatty acids, which can reduce the risk of heart disease. Organic produce also contained more total phenols, which work as antioxidants.

Other studies have shown that children who eat organic produce had lower levels of pesticide residue in their urine than those consuming regular produce. But the differences were too small to draw general conclusions.

Regardless, don’t make nutrition a deciding factor in whether you go organic or stick to standard fare. An apple a day is still healthy no matter how it’s grown.