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A Gut Health Nutritionist’s Guide to GMO’s

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GMO’s and food chemicals directly impact our gut health and how we feel on a daily basis. I’m breaking it all down in this article and sharing an updated Clean 15 and Dirty Dozen list to keep it simple!

Avocado is a clean food on the clean 15 list
GMO health risks

Reading Time: 7 minutes


GMO’s impact our gut health and have a tremendous impact on how we feel and function. Did you know that 80% of our food is genetically modified and the average American will eat about 30,000 GMO’s today alone? Yes, you heard that correctly! 

October is National Non-GMO month and it is my mission to inform you about the environmental dangers, gut health side effects, and future considerations of GMO’s in our food supply.


Genetically Modified Organisms (GMO’s) are living organisms whose genetic material has been artificially manipulated in a lab through engineering.

This organism is created by using a combination of plants, animals, bacteria, and virus genes that don’t occur naturally through traditional development. This basically means that our food is being manipulated and isn’t as “natural” as we think anymore.

So why do we use them in the first place you may ask? I have asked this question so many times myself. We can probably get into a long discussion about that but we will skip over that part for the sake of this article. GMO’s in short prevent browning, enhance taste, increase size, keep costs down, and increase the quantity of products over a shorter duration.


With an abundance of packaged and processed foods in the marketplace nowadays, we are seeing an increase in GMO’s in just about every product since soy and genetically modified oils and fats are typically used as an ingredient to extend shelf life.

GMO’s are found just about everywhere we look but are going to be found primarily in crops such as:

  • Canola
  • Corn
  • Cotton
  • Soy
  • Sugar beets
  • Papaya
  • Zucchini
  • Yellow squash

Other foods typically high in GMO’s: 

  • Beef
  • Poultry
  • Eggs
  • Milk
  • Cheese
  • Honey
  • Seafood 


We are living in an environment where food is being manipulated. Over the past few decades, food has been genetically altered with hybridization techniques. Processed factory-made foods that have no nutrients fill the shelves in the grocery store. We are living in a time with depleted soil and industrial farming. Our increased chronic stress is robbing us from nutrients. In addition, our living environment is toxic, we lack adequate sunlight, and food travels way too far to make its way to us. This is only scratching the surface but some of the reasons we’ve seen a decline in gut health and nutrition in general. 

Unfortunately, the United States is one of the only regions where GMO labeling isn’t required. In fact, 60 countries around the world require GMO’s to be labeled on products and about 300 regions have actually implemented a ban on GMO’s altogether. This is primarily because of the health studies that link GMO’s with disease.


The toxic herbicide known as roundup contains an ingredient called glyphosate. This toxic ingredient has been confirmed as a carcinogenic compound and poison that poses long term impacts on gut health which are still unknown.

Besides glyphosate being cancerous, it is also studied and linked to contribute other health imbalances and impact our gut health specifically.

Autoimmune Conditions

An autoimmune disease develops when your immune system fails to recognize the body’s healthy cells. GMO’s can contribute to: 

  • Hypothyroidism 
  • Celiac disease
  • RA
  • Lupus 
  • MS
  • Diabetes


The majority of children in the US now have life-threatening allergies to corn, milk, peanuts or other GMO foods. Here are some scary statistics: 

  • Peanut allergies alone doubled since the start of GMO’s
  • 1 out of every 50 children is allergic to peanuts in the United States
  • Peanuts and peanut butter is banned from most schools 
  • Over the last 10 years 1 out of every 17 children in the U.S. developed a food allergy
  • Over the last 10 years hospital emergency rooms across the nation experienced a 400% increase in food allergy emergencies

Altered Digestive Health

80% of your immune system is in your gut. The following is a result of excess GMO’s on gut health:

  • Dysbiosis (imbalances of prebiotics and probiotics)
  • Decreased naturally occurring enzymes 
  • Decreased stomach acid
  • Increase in food sensitivities & intolerances 
  • Leaky gut & intestinal permeability 

Altered Brain Function

The gut is the second brain. If the gut is altered, so is the health of our brain. GMO’s alter brain chemistry and have been linked to: 

  • Alzheimer’s 
  • ADHD
  • Anxiety 
  • Depression 
  • Autism 

Hormone Imbalances

GMO’s are known to contribute to imbalances that alter sex hormones which can contribute to:

  • Premature sex organ development 
  • Mood disorders 
  • Sleep disorders 
  • Infertility 
  • Birth Defects 

Slowed Metabolism 

We are what we eat! GMO’s can impact our genetics, detoxification, and metabolism causing gut health imbalances that can lead to:

  • Obesity & weight gain 
  • Difficulty losing weight 
  • Altered blood sugar metabolism 
  • Chronic Fatigue 
  • HPA Axis Dysfunction
  • Vitamin & mineral deficiencies


The list of actual symptoms associated with these conditions and gut health imbalances are still being studied. The good news is you CAN avoid GMO’s by making simple changes to your diet and shopping in the right health food store.


I recommend trying your best to eat organic as much as possible! It really does make a difference and it is worth the investment to your health. I teach my clients to read and look out for the PLU sticker on fruits and vegetables and make sure the 5-digit code starts with a number 9 which ensures that it is organic. If it starts with an 8, it contains GMO’s. If it starts with any other number, it contains pesticides and the farmer may use roundup. 

A slogan I use often to help people remember this, “I HATE 8, 9 IS FINE”. You can also look for the USDA organic label on meats and dairy as well as the non-GMO project verified label with the butterfly which is easy to identify on a packaged product.

One of the reasons I personally love shopping at a health food store that adheres to the non-GMO project is because I know that nothing is even allowed inside if it contains GMO’s. This peace of mind is everything for me! 


I often get asked if I always buy and eat everything organic. I’ll be the first to tell you that gut health nutritionists like myself don’t eat perfect all the time or avoid GMO’s completely!

While I try to do my best to eat mostly organic, it’s just about impossible in some situations such as traveling, events, dining out, etc. I am a big believer in having BALANCE. With that being said though, there are certain types of produce that I stay clear of because they are known to be high in GMO’s compared to others. This is where the “Dirty Dozen” and “Clean 15” come in really handy. In honor of Non-GMO month, I want to make sure you have this handy list!


The EWG (Environmental Working Group) is committed to protecting the environment and human health. They publish reports relating to water quality, toxins in cosmetics, and GMO’s. 

The EWG’s Shopper’s Guide to Pesticides in Produce™ (aka Dirty Dozen and Clean 15) is revised and updated each year. The guide ranks pesticide contamination on 47 of the most popular and common fruits and vegetables. Results are based on more than 35,200 samples tested by the U.S. Department of Agriculture and the Food and Drug Administration. 

The top 15 foods with the least pesticides and GMO’s are referred to as the Clean 15. The 12 foods with the most pesticides are called the Dirty Dozen. 


These are best to buy conventional (not organic) – Updated 2020

  1. Avocados
  2. Sweet Corn*
  3. Pineapple
  4. Onions
  5. Papaya
  6. Sweet peas (frozen)
  7. Eggplants
  8. Asparagus
  9. Cauliflower
  10. Cantaloupe
  11. Broccoli
  12. Mushrooms
  13. Cabbage
  14. Honeydew melon
  15. Kiwi


Buy these organic whenever possible – Updated 2020

  1. Strawberries
  2. Spinach
  3. Kale
  4. Nectarines
  5. Apples
  6. Grapes
  7. Peaches
  8. Cherries
  9. Pears
  10. Tomatoes
  11. Celery
  12. Potatoes

+ EWG’s Dirty Dozen Plus: 

  • Hot Peppers 
  • Sweet Bell Peppers
Dirty Dozen and Clean 15 list updated


You might be wondering about all the other produce. The EWG ranks the produce that typically contains the most GMO’s and pesticides from 1 to 47, so there are definitely foods in between the Clean 15 and Dirty Dozen. Here is the FULL list that shows the order from most amounts of pesticides at the top (Dirty Dozen), to the fewest pesticides (Clean 15).

1. Strawberries

2. Spinach

3. Kale

4. Nectarines

5. Apples

6. Grapes

7. Peaches

8. Cherries

9. Pears

10. Tomatoes

11. Celery

12. Potatoes

13. Sweet Bell Peppers

14. Cherry Tomatoes

15. Lettuce

16. Cucumbers

17. Blueberries

18. Hot Peppers

19. Plums

20. Green Beans

21. Tangerines

22. Raspberries

23. Grapefruit

24. Snap Peas

25. Winter Squashes

26. Carrots

27. Oranges

28. Summer Squashes*

29. Bananas

30. Sweet Potatoes

31. Watermelon

32. Mangoes

33. Kiwi

34. Honeydew Melon

35. Cabbage

36. Mushrooms

37. Broccoli

38. Cantaloupe

39. Cauliflower

40. Asparagus

41. Eggplant

42. Sweet Peas Frozen

43. Papaya*

44. Onions

45. Pineapple

46. Sweet Corn*

47. Avocados

Clean eating food list


Eat local! Choosing locally grown food in your area reduces the GMO risk. In addition, get to know your farmer! Most local farms actually practice organic farming, but don’t label due to the high cost and regulations. 

Add avocados! As if you needed another reason to love avocados, they are #1 on the list which just makes everything right in the world. Avocado makes an excellent healthy fat source and is an incredibly versatile ingredient in meals, deserts, and smoothies. 

Wash your produce! Just because something is on the Clean 15 list or is organic, doesn’t mean you don’t have to wash it. I suggest rubbing and rinsing produce in warm water with a small amount of coconut oil or soaking in filtered water with a few tsp of baking soda and drops of grapefruit seed extract. 

Keep these lists handy! Pin the pictures below and take them with you to the grocery store so that you know when to buy organic and when it’s okay to buy conventional if needed. 

For additional food resources, check out my resources page with a list of the best online food delivery companies for non-GMO produce, meat, fish, and groceries

Happy shopping!

Foods high in GMO's and pesticides

  1. Amy Byrne says:

    Great article!!!! This is a great resource to share with others….explains everything in detail but simple and easy to understand. Thank you!!!

  2. Attracta Lyndon says:

    Thank you Nikki. This list is so helpful.

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