You go to the grocery store to pick up a couple of apples and some salad fixings. Standing in front of the display of apples, you once again question whether the extra cost for organic apples is worth it.

You may wonder – Is there real research showing that eating organic matters? Will eating organic help you get pregnant?  YES! Research shows that eating conventionally grown fruits and vegetables that contain pesticide residue can reduce your chances of getting pregnant.

Avoiding pesticides by eating organic is important for fertility….  Now let’s dig into the science to see why this is true.

What does the ‘organic’ label mean?

In the U.S., for a product to be certified as organic, it has to meet standards set by the U.S Department of Agriculture.  These standards include specific farming practices and a focus on sustainability. The organic standards also limit the types of pesticides.  Most of the synthetic pesticides, growth hormones, and synthetic fertilizers are prohibited. (source)

Conventional agriculture, on the other hand, usually involves using synthetic fertilizers and pesticides when growing crops.

Does organic food contain more nutrients?

The answer here may surprise you. Most studies show that organic and conventionally grown foods are similar in their nutrient profiles. (study) (study)(study)

There are a few specific foods that have higher antioxidant capacity in the organically grown vegetables. Specifically, organic onions have more flavonoids available. (study)

Likewise, there are a couple of studies showing that a few conventionally grown crops, such as oranges, may have a little higher antioxidant capacity. (study)

If organic food isn’t wildly more nutritious, why does it affect fertility?

The research shows that the presence of pesticides on conventionally grown foods is what is reducing fertility for both men and women.

A study published in the Journal of the American Medical Association in 2018 details the impact of conventionally grown foods on fertility.

The study participants were 325 women who were undergoing ART (assisted reproductive technology such as IVF) at Massachusetts General Hospital Fertility Clinic.

Researchers assessed their exposure to pesticides, determining overall fruit and vegetable consumption and how often they chose organic produce.

When the researchers divided the participants by the amount of conventionally grown fruits and vegetables, a significant difference was seen.

The women who consumed a lower amount of pesticide residue (bottom 25%) were 26% more likely to give birth than those who ate more foods with pesticide residue (top 25%).

The women in the low pesticide group ate less than one serving a day of conventionally grown (high pesticide) fruits and vegetables. The women in the high pesticide group were eating more than 2.3 servings per day of conventional fruits and vegetables.

Does eating organic affect sperm quality?

Recent studies have investigated the question of how pesticide residue impacts sperm quality.

One study found that men who ate more servings of fruits and vegetables with pesticide residue had lower sperm counts. When comparing the high pesticide (top 25%) versus low pesticide (bottom 25%) groups, the men who ate more fruit and vegetables with pesticide residue had a 49% lower total sperm count. 

Eating organic – or avoiding conventionally grown produce – makes a big difference for men!  *** The total amount of fruits and vegetables eaten didn’t relate to sperm quality, only the amount of pesticide residue was important in this study. *** (study)

Another study found similar results, but through looking at the other side of the picture. The results showed that men who ate higher amounts of organic fruits and vegetables had sperm concentrations that were about 170% higher than that of men who ate less of the organic produce.(study)

Getting specific on pesticides:

The most commonly used pesticides in the US are organophosphates and pyrethroids.  These are two broad classes of pesticides which contain many different specific brands and types.

In the US, the Environmental Protection Agency (EPA) determines whether a pesticide is safe for human use.  The FDA then monitors and enforces the regulation on both raw and processed agricultural products.  For meat and poultry, the USDA is in charge of monitoring and enforcing the regulations. (source)

Not all fruits and vegetables have high amounts of pesticide residue on them.  The Environmental Working Group, a non-profit activist group, comes out with a ranking each year of the fruits and vegetables with the highest burden of pesticide residue.

Their 2019 list of foods with the highest pesticide residue (the ‘Dirty Dozen’) includes:

• Strawberries
• Spinach
• Kale
• Nectarines
• Apples
• Grapes
• Peaches
• Cherries
• Pears
• Tomatoes
• Celery
• Potatoes

This is an eye-opening list for anyone who makes a morning green smoothie using conventionally grown spinach and kale!

What happens when you eat something with pesticide residue?

Your body is great at getting rid of things it doesn’t need. Think about how many toxins you breathe in, put on your skin, or consume each day. Even certain components of healthy foods are considered toxic by your body and need to be eliminated. In our modern era, we are expecting a lot from our body’s detoxification system!

Two phases of detoxification:
To get rid of toxins, your body first uses enzymes to break apart (metabolize) the toxin and add a reactive site to it, usually by adding an oxygen molecule. This is referred to as Phase I detoxification.

Next, your body adds a water-soluble group to the metabolized compound in order to make it easy for the body to excrete. This is Phase II detoxification.  Both parts need to be working together to get rid of pesticide residue.

The phase I enzymes are known as the cytochrome P450 (or CYP450) enzymes. Different CYP450 enzymes break down different pesticides (and medications, toxins, etc).  There are several common genetic variants that impact how well people break down substances. Researchers have determined which phase I enzymes are important for breaking down different pesticides. (study)

Genetics influences how you metabolize pesticides:

Since people can have genetic variants that impact how well they break down pesticides, the question of how much any specific pesticide will impact you depends on your genes.

In other words, avoiding pesticide residue is important for everyone, but for some people, it could make an even bigger difference when trying to conceive.

Pyrethroids:
Pyrethroid pesticides are frequently used for home pest control as well as in conventional agriculture. The different pyrethroid pesticides are metabolized through the enzymes CYP2C9, CYP2C19, and CYP3A4. (study)

One specific pyrethroid, esfenvalerate, is broken down by CYP2C9. (study) Genetic variants in this gene change the rate at which it is broken down.

If you have your genetic data from 23andMe or AncestryDNA, you can check to see if your CYP2C9 gene is functioning normally.

Check your genetic data for rs1799853:

• T/T: reduced enzyme function(study)
• C/T: somewhat reduced enzyme function
• C/C: normal enzyme function

People who carry this genetic variant are likely to not break down pyrethroids as well.  Eating organic may be even more important!

Organophosphates:
Organophosphates are another very commonly used class of pesticides.  They work by damaging an enzyme called acetylcholinesterase, which controls signaling between nerves. Long term exposure to organophosphates, commonly seen in farm workers, can cause confusion, loss of memory, depression, and loss of appetite. (source)

The enzyme CYP2B6 converts the organophosphate chlorpyrifos into its active form, which is an acetylcholinesterase inhibitor.(study)

Some people carry a variant of this gene that decreases the function, which in this case means that they may have less of the toxic effect from organophosphates. Sometime carrying a genetic variant can be a good thing!

Check your genetic data for rs3745274:

• T/T: reduced enzyme production, reduced conversion of chlorpyrifos into acetylcholinesterase inhibitor.
• G/T: somewhat/slightly reduced enzyme production,
• G/G: normal function, converts chlorpyrifos into an acetylcholinesterase inhibitor

Again, most people convert chlorpyrifos into the active form, which is an acetylcholinesterase inhibitor – not a good thing.

Only the 10% of people who carry the TT genotype will have greatly reduced conversion of the organophosphate – a very good thing.

You may be wondering, then, what happens to the organophosphate chlorpyrifos if someone carries the genetic variant in CYP2B6?

Other enzymes also break down the chlorpyrifos.  Different variants of these genes causing people to break down this pesticide differently.

Your body has multiple pathways for many functions, including eliminating toxins such as pesticides. The combination of all of your genetic variants interacts with your environment – what you eat, toxins you’re exposed to, medications you take.

Understanding some of these pathways can help you to make the best decisions on how to optimize your health when trying to conceive.

Practical advice on avoiding pesticide residue:

If you are trying to get pregnant, both you and your partner should avoid eating conventionally grown fruit and produce with high pesticide content.  This means, at the minimum, you should avoid eating conventionally grown produce on the EWG’s ‘Dirty Dozen’ list.

Here is the 2019 Dirty Dozen list again:

• Strawberries
• Spinach
• Kale
• Nectarines
• Apples
• Grapes
• Peaches
• Cherries
• Pears
• Tomatoes
• Celery
• Potatoes

There are fruits and vegetables that don’t have as much pesticide residue when conventionally grown. If you have a tight budget for groceries, you can save a little money by sometimes buying conventionally grown produce from the Environmental Working Group’s “Clean 15” list.

The EWG’s 2019 Clean 15 list includes:

• Avocados
• Sweet Corn
• Pineapples
• Sweet Peas, Frozen
• Onions
• Papayas
• Eggplants
• Asparagus
• Kiwis
• Cabbages
• Cauliflower
• Cantaloupes
• Broccoli
• Mushrooms
• Honeydew Melons

Additionally, you should try to limit your exposure to household pesticides that have been recently sprayed.