Content Library Articles Pesticides, Herbicides, Fertilizers, Oh My!

Pesticides, Herbicides, Fertilizers, Oh My!

Pesticides, Herbicides, Fertilizers, Oh My!

True or false? The benefits of organic vegetables are overstated because studies show they’re no healthier than conventionally grown food.

That’s a big false! Unless you like having lethal chemicals inside your body, I highly recommend going organic. The one study showing no difference between organic and conventional was funded by the food and agriculture industry. Many other studies have linked organic vegetables to a decrease in negative effects from pesticides and have found that organic vegetables contain more nutrients and phytochemicals than conventional ones.

Conventionally grown produce requires the use of toxic chemicals designed to kill insects and other pests. Should we be surprised to learn that these substances may not be completely harmless where our own health is concerned? There’s no question that residues of these chemicals remain on the fruit and vegetables we eat, and then make their way inside our bodies.

These chemicals have been linked to cancers and other ailments. They also hurt us indirectly when our soil and water are contaminated. Researchers link chemical pesticides found in food and water, especially atrazine and dichlorodiphenyldichloroethylene (DDE), with increases in body mass index (BMI) in children and insulin resistance in rodents. Even nitrogen-based chemical fertilizers intended to make plants grow damage the environment. We have a dead zone in the Gulf of Mexico that is the size of New Jersey where nothing can live because the fertilizers fuel the algae, which steals the dissolved oxygen in the water so no other living things can survive.

Pesticides became a mainstay as a way to increase the yield and profitability of farming. But there’s plenty of evidence that they’re neuro-toxic and carcinogenic for those of us who eat them. A large meta-analysis in the journal Neurotoxicology found that chronic exposure to some common pesticides significantly increased the risk of Parkinson’s disease. Farming is one of the most dangerous occupations because of that. Studies in adults and children have also linked pesticide exposure to kidney, pancreatic, prostate, breast, and stomach cancers, as well as respiratory problems and depression.

Wind and runoff carry these harmful chemicals from farms into rivers and surrounding areas, affecting even those of us who don’t consume them in our food. And they linger in the environment—and our bodies—for decades. In a 2005 report, the Environmental Working Group found DDT in the umbilical cords of babies before they even took their first breath. These toxic chemicals stick around for dozens or sometimes hundreds of years, even after their use is banned or stopped.

I know this all sounds scary, but you can greatly lower your exposure to pesticides by eating organic. A 2015 study funded by the EPA found that consumers who often or always bought organic had significantly less insecticides in their urine, even though they ate 70 percent more produce than people who bought only conventionally grown fruits and vegetables.

As you’ve no doubt noticed, organic is often costlier, which can be an obstacle for many people. Is it worth it? In some cases, absolutely. The Environmental Working Group (EWG) ranks the fruits and vegetables that are most contaminated with pesticide residue. That list, known as the “Dirty Dozen,” can tell you which foods you must buy organic. The EWG also keeps a list of the foods that have the least amount of pesticide residues, known as the “Clean Fifteen.” You can go to for the lists and background report in its entirety. The EWG research turned up some interesting information:

Organic agriculture offers a safer alternative, but not one that’s easily available (or affordable) for everyone. If our only choice is non-organic produce or no produce at all, we should choose the former. But I believe we can do better than that. Some of us can grow at least some of our food. That way we can make sure no harmful chemicals were used, and we save money, too. Second, we can choose the vegetables and fruit that are proven to have the least amount of pesticide residue.

There really is no need to buy everything organic. If we buy in-season produce at farmers’ markets from small local growers, we probably also wind up eating healthier food. Finally, we can use the research done by the Environmental Working Group to guide us: the EWG analyzes USDA figures to come up with its famous Dirty Dozen and Clean Fifteen lists—the produce that have the most and least amount of pesticide residue. Below, you’ll find the big list, 48 foods ranked from most pesticide to least. I would focus on the bottom 30 of the list if you can’t find organic. And if you want to eat any of the foods in the top 20, then choose organic as much as possible.

  • Strawberries
  • Apples
  • Nectarines
  • Peaches
  • Celery
  • Grapes
  • Cherries
  • Spinach
  • Tomatoes
  • Sweet bell peppers
  • Cherry tomatoes
  • Cucumbers
  • Imported snap peas
  • Domestic blueberries
  • Potatoes
  • Hot peppers
  • Lettuce
  • Kale/collard greens
  • Imported blueberries
  • Plums
  • Pears
  • Raspberries
  • Carrots
  • Winter squash
  • Tangerines
  • Summer squash
  • Domestic snap peas
  • Green onions
  • Bananas
  • Oranges
  • Watermelon
  • Broccoli
  • Sweet potatoes
  • Mushrooms
  • Cauliflower
  • Cantaloupe
  • Grapefruit
  • Honeydew
  • Eggplant
  • Kiwi
  • Papaya
  • Mango
  • Asparagus
  • Onions
  • Frozen sweet peas
  • Cabbage
  • Pineapples
  • Sweet corn
  • Avocados

I hope this list is helpful when you’re deciding whether or not to choose organic. For more information about what foods to eat to promote health and avoid dis-ease, check out my new book, Food: What the Heck Should I Eat?

Wishing you health and happiness,
Mark Hyman, MD

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