The Gut-Pesticide Connection [Plus Other Reasons to Shop Local + Organic]

The Gut-Pesticide Connection [Plus Other Reasons to Shop Local + Organic] - Part 1/2

We hear all the time that we should buy organic food, especially produce, but have you ever wondered why? There are a number of reasons, but as “America’s Gut Doctor” the reason that sticks out to me the most is to protect our gut. Not many people know this, but pesticides and other chemicals that are used to grow conventional produce can wreak havoc on your gut health… so the push for us to eat organic food as much as possibly is definitely something we should strive for.

Of course, some fruits and vegetables are more likely to contain higher pesticide levels than others. In this week’s blog post, I cover the most common pesticides you should know about, how they impact your gut health, and how to avoid them (Including a list of the highest and lowest pesticide-ridden fruits and veggies!).

Here’s everything you need to know about pesticides and gut health.

The Gut-Pesticide Connection

When it comes to demonstrating the impact of pesticides on our gut health, the evidence is clear: exposure to toxic environmental agents, like pesticides, can cause problems in our gut microbiome. A study published in 2020 found that “environmentally induced perturbation in the gut microbiome is strongly associated with human disease risk.” In other words, environmental toxic chemicals have a detrimental effect on the gut microbiome, leading to the diseases associated with microbiome disturbances. These diseases include inflammatory bowel disease (IBD), obesity, diabetes, cardiovascular disease, liver disease, colorectal cancer, neurological disorders, and more. Most commonly, environmental toxins like pesticides can lead to liver damage and a condition called leaky gut . In particular, glyphosate, a widely popular herbicide used to kill weeds and unwanted grasses, has been shown to cause an overgrowth of pathogens in the gut , which then causes the gut lining to break down, leading to leaky gut and inflammation, which fuels the fires of chronic disease in the body.

Fortunately, one positive outcome of the pandemic and the stay-at-home orders is that a large number of people started growing their own vegetable gardens. I mention this later on, but growing your own food on organic soil can cut down on your pesticide exposure, and thus help you protect your gut from harm. Bottom line: Given how closely our health and disease risk is tied to our gut health (and the health of your gut microbe ecosystem)—see other articles I’ve written on this here and here —it’s fair to say that avoiding pesticides is a smart decision for your overall well-being and longevity.

Top Pesticides To Be Aware Of (& What They Can Do To Your Health)

As you may already know, the purpose of pesticides is to keep unwanted pests, like insects, weeds, rodents, and fungi, off produce while it’s being grown and harvested. On the surface this sounds like a good thing, but these chemicals have been shown to have harmful effects on humans. In fact, pesticide exposure has been linked to increased risks of numerous conditions from cognitive dysfunction , cancer , and cardiovascular disease , to Parkinson’s disease and reduced fertility . Studies have also found that children, whose brains and bodies are still developing, are especially susceptible to neurological damage caused by pesticide exposure .


The U.S. government does little in the realm of helping keep us safe from pesticides, despite the growing body of evidence that shows their harmful effects. The EPA has limits on the amount of pesticides that can be used in commercial farming, but keep in mind, they’re weighing the health risks (what happens to us) versus the reward (the money farms make and pay taxes on), so let’s just say our best interests aren’t exactly aligned. 


There’s no easy way for you to know which specific pesticides are being used on the food you buy, but for your own peace of mind, here are a few of the most common pesticides and the negative health outcomes they’ve been tied to.

1. Chlorpyrifos

According to researchers at Harvard University , chlorpyrifos is the most widely-used pesticide on crops like corn, soybeans, broccoli, and apples . Its residue is also found on peaches, nectarines, bell peppers, snap peas, hot peppers, and cilantro . Chronic exposure to chlorpyrifos is most dangerous to children—it can impair their developing brains. Children exposed to chlorpyrifos in the womb may have slower reflexes, as well as higher risks of ADHD and other developmental disorders.

2. Glyphosate

Used to kill weeds and grasses that threaten plants and produce and sprayed on Roundup Ready GMO crops, glyphosate has been linked to increased risk of cancer, endocrine-disruption, celiac disease, autism, and leaky gut syndrome . In 2015, it was reclassified as “probably carcinogenic” by the International Agency for Research on Cancer. Since then, many countries have limited or banned the use of glyphosate, but the U.S. has not, despite the many pleas of human rights groups .

3. Atrazine

Another herbicide, atrazine is also used to kill grass and weeds. The Agency for Toxic Substances and Disease Registry issued a public health statement in 2003 claiming that exposure to atrazine can harm pregnant women, their children, and women who are trying to conceive. Specifically, maternal exposure to atrazine has been associated with low fetal weight and heart, urinary, and limb defects. It can also cause complications during pregnancy , like preterm birth, which can threaten the life and long-term health of a baby. Due to agricultural runoff, atrazine has even contaminated the Chesapeake Bay, where it has resulted in hermaphrodite frogs and is disrupting the microbiome of juvenile oysters , allowing them to be colonized by pathogenic bacteria and affecting their repopulation in the bay.

The Highest & Lowest Pesticide Fruits and Vegetables

While our goal should be to consume as few pesticides as possible, it’s worth noting that certain fruits and vegetables are historically sprayed with more pesticides than others. If you aren’t already buying organic produce and need somewhere to start, the best place to start is with these high-pesticide fruits and veggies. In other words, if you can only afford to buy some organic produce, these are the ones you want to buy organic ALWAYS. According to the Environmental Working Group and data from the USDA, the following fruits and vegetables are contaminated with the highest levels of pesticides. They call these the “Dirty Dozen.”

EWG’s “Dirty Dozen”

1. Strawberries

2. Spinach

3. Kale, collard greens, and mustard greens

4. Nectarines

5. Apples

6. Grapes

7. Cherries

8. Peaches

9. Pears

10. Bell peppers and hot peppers

11. Celery

12. Tomatoes

On the flip side, there are also fruits and veggies that tend to have lower levels of pesticide residue. These are the ones that you can feel safer buying conventional or local versions if you cannot find or afford to buy everything organic. These are often referred to as the “Clean Fifteen.”

EWG’s Lowest Pesticide Fruits & Vegetables

1. Avocados

2. Sweet corn

3. Pineapple

4. Onions

5. Papaya

6. Sweet peas (frozen)

7. Eggplant

8. Asparagus

9. Broccoli

10. Cabbage

11. Kiwi

12. Cauliflower

13. Mushrooms

14. Honeydew melon

15. Cantaloupes

Per usual, I like to end these blog posts by giving you clear and actionable next steps—in this case, for protecting your gut health, and avoiding pesticides. Here are my top five tips.

5 Ways To Heal Your Gut & Avoid Pesticides

Organic produce for sale at Callicoon Farmer’s Market in Callicoon, NY

1. Buy Organic

Aside from growing your own food or asking your local farmer about their growing practices, buying organic fruits and vegetables is the only way to guarantee that your food hasn’t been treated with pesticides. I recognize that this isn’t practical for everyone, but if you can focus on buying organic versions of the “Dirty Dozen,” that in itself will decrease your exposures significantly.

2. Shop at a Farmer’s Market

In general, produce grown on small local farms contains fewer pesticides than produce grown on a giant industrial farm. Not to mention, their methods are usually more sustainable and the produce itself is richer in nutrients. Shopping at a farmer’s market lets you contribute to the local economy, not huge industry farms, and you also get to know your local farmers, who can explain their farming practices, including if they use pesticides. It’s a great opportunity to get to know your food and where it comes from.
Dr. Pedre shopping at a local farmer's market

Dr. Pedre shopping at a Willow Wisp Organic Farm in Damascus, PA

Happy Gut 28-Day Reboot

3. Do the HAPPY GUT® Cleanse

If you haven’t been buying or eating organic produce up to this point, chances are your gut health could use a boost (especially if you suspect that you’re dealing with leaky gut syndrome right now). Your gut may be in need of a cleanse, so you can hit the reboot button on your health. My HAPPY GUT ® REBOOT: 28-Day Cleanse is designed to do just that. I created  the REBOOT with all gut conditions in mind, and it has helped thousands of people rebalance their gut, improve the health of their gut lining, and rebalance their gut microbiome.
Homegrown organic garden
Homegrown organic garden
Homegrown organic garden

Dr. Pedre’s “Urban Farm Oasis” in NYC, designed by Betty-Baines Saum

4. Grow Your Own Produce

Growing your own food has numerous benefits, the most important one being that you can do it pesticide-free! Naturally this depends on where you live and the climate, but even growing a portion of your fruits and vegetables can make a difference with regards to your pesticide exposure. Head to your local gardening shop and see what tools and seeds they recommend for your area. Or bring it indoors, and grow a vegetable garden year-round with a Click & Grow Smart Garden .
Produce Soaking in a Sink

Soaking and washing produce in a sink

5. Wash Your Food Before You Eat It

Washing your fruits and vegetables when you bring them home from the market is another easy way to cut your pesticide intake. Pesticides are sprayed on the outside of produce , so much of the residue resides on the skin. While there are pesticides designed to get into the flesh of fruits and veggies with softer, thinner peels, that’s not something you can control unless you buy organic or grow your own. 

To get rid of some pesticides, mix together 1 cup of distilled white vinegar and 4 cups of water (you can add some lemon juice if the vinegar smell turns you off). I like to do this in a large bowl in the sink. I soak each item for a couple of minutes and make sure to scrub the skin thoroughly if I’m going to consume it. Then, I rince the fruit or vegetable thoroughly with water and pat it dry before putting it away.

We hear the advice to eat organic all the time, but sometimes it’s important to pause and dive into the “Why?” behind a popular piece of advice. When it comes to avoiding pesticides, your gut will thank you now and for years to come. 

Stay tuned for next week’s blog — part 2 of this special series on shopping local and organic — where I’ll share my favorite seasonal veggies and tips for making the most of your local farmer’s market.

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