Fungicides, Fungi, and the Fantasy of Pure Food

They danced for hours, wildly and at times in uncontrolled gyrations, until one collapsed from exhaustion. Some of the dancers had convulsions; others hallucinated. Some even experienced a horrible burning sensation in their arms and legs, followed by their flesh turning black and shedding. Believing themselves cursed, they would travel to the chapel of St. Vitus, hoping for a cure. Today, we believe these outbreaks of mania, especially the medical changes to the limbs, were due to ergot, a mold that infects damp rye, producing psychotropic alkaloids similar to LSD. From roughly 1250 to 1750, ergot was among the leading causes of child mortality, disappearing only when ergot-susceptible rye was replaced by wheat and potatoes.

It is a useful reminder that food risk predates synthetic pesticides. Long before modern chemistry, nature was producing its own toxins.

The Other Side of the Dirty Dozen

In the last few weeks, the Environmental Working Group (EWG) published its annual Dirty Dozen, highlighting pesticide residues. Among the most frequently detected were Fludioxonil, found in 14% of all produce samples, and Fluopyram, among the top 10 most detected – both are fungicides. While the EWG emphasized potential harm, it was silent on the other side of the ledger: what those fungicides may be preventing. A new study in Food Control examines mycotoxins produced by fungi, such as ergot, that may be present in our foods.

In addition to eating fresh fruit and vegetables, we are encouraged daily to transition to a plant-based diet for our health and that of the planet. [1] However, the same problem follows us into the foods we increasingly regard as safer, cleaner, or more sustainable. While the putative nutritional benefits of plant-based meat alternatives and beverages have been documented, there remain “significant gaps” in our safety assessment, especially for unregulated contaminants like mycotoxins.

Mycotoxins are toxic metabolic byproducts of Aspergillus and Fusarium that frequently contaminate crops used as raw ingredients for plant-based “meats” and beverages. They can be quite toxic to our liver, kidneys, and immune system, and in the case of aflatoxins, are classified as a Group 1 carcinogen. For comparison, glyphosate is considered, at least by the EPA, "not likely to be carcinogenic to humans." As is the case with the fungicides called out by the EWG, once mycotoxins are produced, they are highly stable and difficult to remove using conventional food processing. 

The Plant-Based Risk Ledger

The researchers purchased 212 plant-based products from the top five retail stores in the UK, representing the majority of alternative meats (92) and beverages (120). Toxins were extracted, separated, identified, and their molecular weights determined. Each unique chemical signature was compared to known standards, allowing confirmation of a toxin’s presence and amount. 

Mycotoxin contamination was a universal feature of plant-based alternatives. Like the EWG Dirty Dozen, some samples contained more than one fungal toxin, and all generally remained within the legal limits for raw cereal. 

• 100% of the plant-based meat alternatives were contaminated, with legume-based and mixed cereal-legume products the most heavily affected. Aflatoxins, a Class 1 carcinogen, were present in over 80% of samples, particularly those containing legumes. Many of the samples also contained “emerging mycotoxins” not yet regulated at all.
• While plant-based beverages generally had lower concentrations, presumably due to dilution by water, the findings were heavily influenced by the primary raw ingredient used, such as oats, almonds, or soy. 90% of soy-based beverages contained Ochratoxin A, a potent toxin and "probably carcinogenic" to humans. Almond-based drinks generally showed the lowest levels of contamination compared with oat and soy.

As more people switch to plant-based diets, our exposure patterns are changing. The researcher’s concern is that finding just one toxin in a product is rare; usually, there is a cocktail of mycotoxins, and we have little information on the synergies among these combinations. Regulatory limits set in isolation may not be as relevant in these situations. Moreover, plant-based meats are often primarily based on legumes, i.e., peas, which are less regulated than wheat or corn.

The food-safety playbook

While the EWG focuses on pesticides in fresh produce, this study examines mycotoxins in plant-based alternative foods. What is striking is that the pesticide-residue argument and the mycotoxin argument are mirror images of each other.

• Both acknowledge that single pesticide or mycotoxin limits are rarely exceeded, so they emphasize focusing on synergistic or additive concerns that are not addressed by regulation. 
• Both note the pervasive exposure to pesticides and mycotoxins, making avoidance nearly impossible.
• Both focus on environmental persistence. In the case of EWG, there is a new focus on “forever chemicals,” and the current study notes that mycotoxins are highly stable and difficult to eradicate.  
• Both attempt to link these contaminants to long-term health risks. For the EWG, this means children who are especially vulnerable during early development. For the researchers, it is the mycotoxin risk of carcinogenicity.
• The EWG ultimately encourages eating produce regardless of its status, although it favors organics. One goal of the current study is to ensure the safety of plant-based foods so they can continue to serve as "healthy and sustainable alternatives."

The Fantasy of Pure Food

What is missing from both EWG’s annual warning and the emerging concern over mycotoxins is the same thing: a sense of tradeoff. Fungicides are not fairy dust, but fungi are not harmless either. If residues of both pesticides and mycotoxins are, to some extent, inevitable, and if our ability to detect them continues to outpace our ability to eliminate them, the relevant question is not whether our food can be made chemically pure. It cannot. The better question is which risks we are willing to accept, which we are willing to reduce, and which we pretend do not exist.

For me, the safety data suggest that trace fungicide residues may be far less concerning than the mycotoxins those fungicides help prevent. The irony is that moving toward plant-based diets to avoid the environmental and health costs of our current food choices does not free us from risk; it simply shifts the risk ledger. St. Vitus’ dance may be gone, but the older lesson remains: nature has never promised us purity. Food safety is not the absence of chemicals. It is the management of competing hazards.

[1] There is no better description of saving the planet than this riff by George Carlin who points out that “the planet is fine.”

Source: Mycotoxin contamination in plant-based beverages and meat alternatives: A survey of the UK market Food Control DOI: 10.1016/j.foodcont.2025.111910