Organic is Better for You (But Not the Way You Think)

When we talk to patients about eating better, vegetables and fruit are a big topic. "Pile on the vegetables at dinner and snack on some fruit," we tell them. "They'll fill you up, they taste great, and the fiber is great for you."

"But organic foods are so expensive - I can't afford that stuff," they tell us.

A lot of people feel that they only way to eat healthy is to eat organic. "It's better for you," they'll insist. Fortunately a thorough review of peer-reviewed research into organic foods was published in the Annals of Internal Medicine (2012;157(5):348-366). Researchers at Stanford University in California did not limit their analysis to the nutrient content of fruits and vegetables, however: they also assessed the levels of contaminants, such as pesticides and bacteria, in fruits and vegetables as well as chicken, pork and beef. Seventeen studies examined the effects of consuming organic foods in humans, while 223 studies looked at nutrients and contamination levels in foods.

After grouping together the data from the relevant studies, the researchers found no significant difference between the levels of Vitamins A or E in organic produce, raw milk, pork, or beef as opposed to those grown by conventional means. Similarly, the levels of protein and fat content were similar in organic and conventional raw milk.

Much more concerning is their findings regarding pesticides. While organic produce was not always pesticide-free (7% of the produce tested positive for detectable levels of pesticides), organic produce was still 30% less likely than conventional produce to test positive for detectable pesticides.

The bacteria E. Coli was found in 7% of organic produce and 6% of conventional produce, which is not considered a significant difference. Animal products fared about equally between organic and conventional, as well, but the levels of contamination were much higher: 67% of organic chicken and 64% of conventional chicken was found to be contaminated with Campylobacter, while 35% of organic chicken was contaminated with Salmonella (versus 34% of conventional chicken). Pork was contaminated with E. Coli, Salmonella, and Listeria monocytogenes.

Overall, organic meats were more likely to be contaminated with E. coli, and it appeared that people who consumed organic meats during the winter were at a higher risk of Campylobacter infection. On the other hand, conventional chicken and pork was more likely to be contaminated with antibiotic-resistant bacteria.

What this means for you

It would appear that organic foods are no more nutritious than conventional foods - and that's good news for those who worry that they're doing their family a disservice by not being able to afford organic foods. And while conventionally-grown produce might be more likely to be contaminated with pesticides than organic produce, choosing organic does not remove that risk altogether. It's still important to wash your produce thoroughly, no matter what type you choose.

That's also true for meats - whether conventional or organic. The levels of bacterial contamination are certainly something you should be concerned about, but this is a matter for caution, not alarm. Wash your hands before and after handling raw meat and always wash your cutting boards and knives in hot soapy water.

First posted: September 12, 2012