Organic foods have few, if any, health advantages over conventional foods, a research review finds. The researchers looked at thousands of prior studies. They focused on 237 that met their standards for how well the research was done. Only 17 studies compared how the foods affected people. The others focused on properties of the foods themselves. Nutrient levels varied greatly, with no clear patterns. Organic produce was 30% less likely to have pesticide residue than conventional produce. Children in 2 studies were less likely to have pesticides in urine if they ate organic diets. But researchers said the amounts were small and within safety limits. Bacteria levels were about the same in both kinds of meats. But the bacteria in the conventionally produced meats were more drug-resistant. They were 33% more likely to resist multiple antibiotics. The journal Annals of Internal Medicine published the study. The Associated Press wrote about it September 4.

By Howard LeWine, M.D.
Harvard Medical School

What Is the Doctor's Reaction?

I doubt the results of this review of the evidence will change many minds. People who believe organic foods are better will continue to pay the extra money. Those who couldn't afford them before still won't be able to afford them. But they might feel a little less guilty if they were concerned about not buying the best for their families.

I am fortunate enough to be able to afford organic foods. But I personally don't ever buy them. I was never convinced that they were healthier. And I doubted that they were safer. I questioned whether organically grown fruits and vegetables might have a higher risk of contamination.

The researchers did a very extensive review of the available evidence about organic fruits, vegetables and meats. They couldn't find enough evidence to show that organic foods improve overall health. But they readily admit that the results varied a lot. So any conclusions should be made with caution.

Regarding safety of organic fruits and vegetables, it was a mixed picture. The risk of pesticide contamination was 30% lower in organically grown fruits and vegetables than in conventionally grown produce. But the researchers' results suggested that some organic produce was more likely to have bacterial contamination than conventional produce. Some organic farms were using manure that did not meet strict standards.

Bacterial contamination of meats was similar for organic and conventional. However, the bacteria in conventional chicken and pork were more likely to show antibiotic resistance. The assumption is that routine use of antibiotics in the feed of conventional chicken and pork causes this resistance.

What Changes Can I Make Now?

If you plan to buy organic, at least be sure that what you are paying extra money for is certified organic. Look for the USDA organic label. To carry the label, the package must contain at least 95% organic content.

Remember "natural" is not the same as "organic." Products labeled "natural" contain no artificial ingredients or added colorings and minimal change from processing. Organic foods are more likely to be natural. But natural foods are not certified organic unless they have the label.

Whether you buy organic or conventional, you need to take the same steps at home to keep food safe.

Wash your hands. Wash your hands with soap and water before handling food. Wash again after you finish, especially if you have handled any raw food. Don't wipe your hands on a dishtowel without washing them first.

Rinse foods. Rinsing under running water can wash off many of the germs that contaminate food. It also reduces any remaining pesticides on fruits and vegetables.

Prepare certain foods on different surfaces. Don't prepare meat and fish on the same surface that you use for other foods. This helps avoid contaminating those foods with bacteria from the meat and fish. Use one cutting board for meats and fish and a second one for produce. Be sure to wash the cutting boards with soap and water after each use. Also, use different knives to cut different foods to prevent cross-contamination.

Cook certain foods thoroughly. Cook all meat, poultry, eggs and freshwater fish. Don't rely on color alone to indicate whether meat is fully cooked. Use a meat thermometer. Cook hot dogs and other precooked meats and fish to destroy bacteria that may have contaminated them in the processing plants.

Store foods properly. Don't leave any foods, before or after cooking, at room temperature for more than 2 hours. Put them in the refrigerator or freezer. Put them away within 1 hour if the air temperature is above 90 degrees Fahrenheit (F). The temperature inside your refrigerator should be 40 degrees F or below. Your freezer should be at 0 degrees F or below.

Wash foods after freezing. Freezing does not necessarily kill bacteria. Wash meats and poultry thoroughly after thawing. Handle them the same as you would fresh meats.

What Can I Expect Looking to the Future?

The people who choose organic foods are more likely to have healthier diets. That means eating more fruits, vegetables and whole grains and fewer processed meats. Eating more plant-based foods is something we all should strive to do. You can do just as well and save money by going the conventional route.