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Organic fruits and vegetables contain a diverse population of “good” bacteria that can promote a healthier gut. Getty Images
  • Researchers found organic apples have a significantly more diverse bacteria population that’s better for gut health than their conventionally grown counterparts.
  • Organic apples also contained the “good” bacteria Lactobacillus, a common healthy probiotic.
  • Organic foods may offer some health benefits, but they’re also more expensive.
  • Experts agree that a majority of people need to increase the amount of fresh fruits and vegetable in their diet, regardless of how they are grown.

When choosing organic or conventional produce, there’s no simple comparison, even if it’s apples to apples.

However, in a new study published in the journal Frontiers in Microbiology, researchers found that when comparing conventionally grown apples to their organic counterparts, organic apples harbored a significantly more diverse bacteria population.

Conventional apples and organic apples both contained about the same amount of total bacteria, about 100 million per apple. But, that’s only if you eat the whole thing — stem, seeds and all.

The production method dictated the types and variety of bacterial colonies.

And that can mean good things for gut health.

“Vegetables and fruits, especially when consumed raw, represent the most important source for a diverse microbial community, which is mandatory for a healthy gut microbiome and our immune system,” said Birgit Wassermann, a PhD student at the Graz University of Technology in Austria, and first author of the study.

Wassermann and her fellow researchers chose to look at apples because of their immense popularity throughout the world.

About 83 million apples were grown in 2018 and production continues to grow. Raw fruits and vegetables are an important source of gut bacteria — cooking tends to kill off all the bacteria.

In the comparison of organic and conventional apples, not only was bacteria more diverse in organic production, but it was also associated with the presence of so-called “good” bacteria Lactobacillus, a common probiotic.

Conversely, conventional apples were more likely to have potentially pathogenic bacteria like Escherichia and Shigella, which are known to cause food poisoning symptoms like diarrhea and cramps.

“The highly diverse microbiome of organically managed apples might limit or hamper the abundance of human pathogens, simply by outcompeting them,” said Wassermann. “Probably, the microbial pool organic apple trees are exposed to is more diverse and more balanced and potentially supports the plant also in resistance during pathogen attack.”

When it comes to gut health, however, Wassermann explained that it’s not as simple as choosing organic over conventional apples.

Such a simple inference can’t be drawn from her work alone. Instead, she emphasizes that diverse populations of bacteria — whether found in nature, apples, or the human gut — tend to be more beneficial no matter the environment where they are found.

And for most people, simply eating more fresh fruits and vegetables is a more important first step than discriminating between apples.

“Organic or conventional? Pretty irrelevant. The main thing is that people eat more fresh produce in general,” said Wassermann.

With a focus on bacteria and by extension, gut health, the research adds yet another lens through which to view the ongoing debate for consumers on how they choose to buy produce.

And the organic versus conventional debate is far from settled.

But as questions about the benefits of either method have become more nuanced — it’s not as simple as saying one is “better” than the other — consumers now have more awareness about what they want out of their produce.

The debate over organic and conventional fruits and vegetables has primarily focused on four aspects: nutrition, environmental impact, cost to consumers, and pesticides.

Depending on how important these factors are to you should inform your purchasing choice rather than strictly choosing one over the other.

Organic is a label conferred by the United States Department of Agriculture (USDA) on foods that are grown in accordance with certain federal guidelines. These guidelines include things like what kinds of pesticides can be used, soil additives, and how animals are raised.

Conventional refers to modern, industrial agriculture which includes the use of chemical fertilizers, pesticides, and genetically modified organisms.

Some studies have found that organic produce likely isn’t any more nutritious than conventional, but it will reduce exposure to pesticides and harmful bacteria.

However, that’s not to say that organic produce is completely free of pesticides — it’s not.

Your choice should also be impacted by other health factors as well, such as pregnancy or other chronic conditions.

Studies in recent years have looked at the prevalence of pesticide exposure among pregnant women via produce, as well as the potential for prenatal pesticide exposure to lead to intellectual disabilities and autism spectrum disorder.

For most consumers, a practical place to start is identifying which fruits and vegetables are more prone to having exposure to high amounts or different varieties of pesticides.

The Environmental Working Group (EWG), an environmental and consumer advocacy group, annually publishes their list of the Dirty Dozen, which are the fruits and vegetables with the highest rates of pesticide contamination, and the Clean Fifteen, which are those with the lowest rates.

The worst offenders from 2019 include:

  • strawberries (coming in at #1)
  • spinach
  • kale
  • nectarines
  • apples

For the produce with the least amount of pesticide exposure, reach for:

  • avocados
  • sweet corn
  • pineapples
  • frozen sweet peas
  • onions

“I usually follow the EWG Dirty Dozen and Clean Fifteen designations,” said Kristin Kirkpatrick, MS, RD, LD, the manager of Wellness Nutrition Services at Cleveland Clinic Wellness Institute.

“There are also certain things that I always recommend to purchase organic, like dairy products and strawberries, as well as foods that I usually tell my clients to skip the cost and go with conventional, like produce with a significant outer layer such as pineapples or bananas,” she said.

Organic foods may offer some health benefits, but they’ll also cost more, and that’s a major consideration for most families.

A 2015 study from Consumer Reports found that organic apples were anywhere from 20 to 60 percent more expensive than their conventional counterparts. Milk was similarly 20 to 64 percent and for things like organic strawberries and zucchinis, consumers could end up paying twice as much.

In short, choosing how and why to pick conventional or organic produce is a serious balancing act. But one thing is for certain: You should be eating more fruits and vegetables no matter how they are grown.

“The most important thing I tell my patients is this: Increasing your fruit and vegetable consumption is far more important than organic versus non-organic. If you choose not to eat fruits and vegetables because you can’t afford organic, that’s the wrong choice. Any fruits and vegetables are better than none,” said Kirkpatrick.