Let's discuss. While we each may have our own (possibly strong) opinion on this topic, my goal is to present what we know from the scientific literature. And I'll be honest, we need more research. That said, independent studies have reported that various pesticides are linked with a host of health problems, including brain and nervous system toxicity, cancer, cardiovascular health, and hormone disruption.
One study that always comes to mind when discussing organic versus conventional foods is this one. The study enrolled 40 Mexican-American children, 3-6 years old: 20 from an urban neighborhood in Oakland and 20 from the nearby agricultural Salinas Valley. The scientists swapped out non-organic food for organic in the kids’ diets and measured the concentrations of pesticides in urine. Urine samples were collected over 16 days – 4 days of the conventional diet, then 7 days of the organic diet, and then 5 days of the conventional diet.
The amount of pesticides in the children in both communities, as measured by urine metabolites, plummeted after they switched to organic food. Metabolites of two neurotoxic organophosphate pesticides dropped by an average of 40% and 49%. Levels of the weedkiller 2,4-D, a possible carcinogen, dropped by 25%. While this study does not prove that organic foods are better or more nutritious per se, it illustrates how quickly diet can positively and negatively affect our pesticide concentrations, suggesting that our health could indeed be impacted by what we choose to eat.
It's important to note that dietary exposure to metabolites of organophosphates and pyrethroids, as well as herbicides such as 2,4-D and glyphosate and their metabolites is especially high among people adopting a conventionally grown plant-rich dietary pattern. I still certainly encourage eating all of those plant foods, but wise to be mindful of the quality, particularly with foods that we consume a considerable amount.
Furthermore, multiple statistical analyses have reported that organic foods contain significantly higher levels of certain nutrients, including vitamin C, iron and magnesium. Epidemiological studies suggest an association between organic diets and lower prevalence of childhood obesity, type 2 diabetes and metabolic syndrome. This 2025 study found that consuming organic food was associated with a lower risk of developing atherosclerotic cardiovascular disease in a middle-aged Danish population. A 6% lower incidence rate of atherosclerotic cardiovascular disease was observed for every 6-point increase in the overall organic food score. In a separate trial, the findings revealed a positive association between the organic food consumption and cognitive function among older adults.
Organic Labels
Organic labels can be used only when foods have been produced in accordance with standards set by the USDA. USDA standards outline production methods that foster “cycling of natural resources, promote ecological balance, and conserve biodiversity”. If a food is labeled as organic, the following are NOT allowed: synthetic fertilizers, sewage sludge, irradiation, and/or genetic engineering. Organically raised animals cannot be given growth hormones or antibiotics.
Pasture-Raised Meat & Dairy
Dioxins and polychlorinated biphenyls (PCBs) are persistent, bio-accumulative and toxic environmental contaminants. Over 95% of human exposure to these concerning chemicals occurs with the consumption of fatty meat and dairy products. Be aware that most toxins are lipophilic, meaning they 'love fat' and will reside in fatty foods. Hence, if including meat in your diet, the thought is that choosing organically-raised meat would result in a lower intake of these toxins. Additionally, pasture-raised meat has been shown to have a higher concentration of the healthful omega-3 fatty acids as well as lower amounts of saturated fats compared with grain-fed or feedlot raised meat. This is also the case for organic milk. And vitamin E content seems be higher in organic milk, meat, and eggs as well.
While farm management and breed type are variables, it seems the benefits of organic dairy are suggested to be primarily associated with the feed type. Some researchers have indicated that pasture feeding conventional cows will remove differences previously reported for organic and conventionally produced milk. The demand for dairy products from grass-fed cows is likely due to the more desirable fatty acid profile, containing higher beneficial omega-3 fatty acids and conjugated linoleic acid.
Organic Produce
Several studies have concluded that organic foods have been convincingly demonstrated to expose consumers to fewer and lower levels of pesticide residues.
The Environmental Working Group (EWG) found that conventionally grown strawberries contained an average of 7.8 different pesticides per sample, almost four times the average of all other produce. A different study reported that organic strawberry farms produced higher quality fruit and their higher quality soils may lead to greater microbial functional capacity and resilience to stress.
Beyond pesticide residues, some research suggests that organic produce yields higher concentrations of protective phytochemicals. In particular, some minerals and antioxidants (phenolic compounds, vitamin C) in fruits, vegetables, and starchy food and carotenoids in fruits and vegetables, are higher in organic foods. Organic plums had significantly greater overall antioxidant capacity and specifically higher polyphenol and anthocyanin concentrations. Additionally, this study reported that organic tomatoes contained a 20% higher concentration of lycopene, a 30% greater amount of vitamin C, a 24% increase in total phenolics and 21% more flavonoids compared with conventional tomatoes. Furthermore, in this study, organic oranges had statistically significantly higher phytochemical content than conventional oranges.
EWG annually publishes the 'Dirty 12' - the 12 produce items that contain the highest level of pesticide toxicity and the 'Clean 15' - the 15 produce items with the least amount of pesticides and pesticide toxicity. For 2024, the ‘Dirty 12’ include: strawberries, spinach, kale/collard/mustard greens, grapes, peaches, pears, nectarines, apples, bell & hot peppers, cherries, blueberries, and green beans. The ‘Clean 15’ include: sweet corn*, avocados, pineapple, onions, papaya*, sweet peas, asparagus, honeydew melon, kiwi, cabbage, watermelon, mango, sweet potatoes, and carrots.
Genetically Modified Organisms (GMOs)
Why did corn and papaya have an asterisk (*) next to their name? While they’re on the Clean 15 list from pesticides, if grown conventionally, you can pretty much guarantee they will be genetically modified. How will you know? The label likely will not read, ‘GMO’, but instead use the term ‘bioengineered food’. While more research is also needed in studying the effects of genetically engineered foods, the Food and Drug Administration currently states that they are safe for consumption. Others argue, however, that these foods may increase allergies, cancer, increased herbicide exposure, and negatively impact honeybees.
GMOs and glyphosate, a widely used herbicide, are at the center of a growing health crisis. GMOs are often engineered to withstand glyphosate, allowing it to be sprayed heavily on crops like soy, corn, and wheat. Unfortunately, glyphosate doesn’t just stay on the farm - it’s in our food, water, and even our bodies. Research shows that glyphosate may disrupt hormones, harm gut health, and even increase the risk of chronic diseases like cancer.
If you wish to avoid GMOs and glyphosate, opt for organic and non-GMO Project Verified foods. Avoid processed foods that contain oils made from corn, soy, and canola. Support local farmers and shop seasonally if you’re able. And filter your water to reduce exposure.
Summary
Consuming organic foods can reduce organochlorine pesticide exposure and the amount of pesticides in our bodies. Some research indicates a greater phytochemical profile with the consumption of organic foods. Opting for organic foods is an environmentally friendly decision working to improve the biodiversity of soils. There may be potential health benefits in regards to different chronic diseases. Additional data on food composition of organic food and dietary intervention studies are needed before health claims about organic food can be confidently made.
Bottom line - if you choose to include meat and dairy in your diet, given that those foods are higher on the food chain, it is most important to consider purchasing organic meat and dairy. Regarding produce, consider opting for organic, particularly for the 'Dirty 12' or instead, substitute a produce item from the 'Clean 15' list. And, if you find that organic foods taste superior, which is certainly possible, you’ll enjoy them even more.
Hope to see you at the local farmer's markets!
In Health,
Natalie