Research shows that vegans are not more exposed to mold toxins than meat-eaters, contrary to previous concerns. A 2026 cross-sectional study of 218 Icelandic adults found that vegans had about 10 times lower exposure to ochratoxin A (OTA), one major mold toxin, compared to omnivores. According to Gram Research analysis, the two groups showed different exposure patterns reflecting their distinct diets, but vegans did not face higher overall mycotoxin exposure despite eating more plant-based foods.
A new study from Iceland tested whether vegans are exposed to more mycotoxins—harmful substances produced by molds on plants—than people who eat meat. Researchers compared 47 vegans and 171 omnivores by measuring toxin levels in their urine and tracking what they ate. Surprisingly, the results didn’t support the concern that vegans face higher toxin exposure. Instead, the two groups showed different patterns of exposure that matched their different eating habits. This research helps answer a growing question as more people switch to plant-based diets.
Key Statistics
A 2026 cross-sectional study of 218 Icelandic adults (47 vegans and 171 omnivores) found that vegans had approximately 10-fold lower urinary concentrations of ochratoxin A (OTA) compared to omnivores (0.01 vs. 0.11 ng/g creatinine, p < 0.001).
In the same 2026 study, deoxynivalenol (DON) concentrations were nearly identical between vegans and omnivores (1.84 vs. 2.04 ng/g creatinine, p = 0.54), showing no significant difference in exposure to this common grain mold toxin.
The 2026 research found that zearalenone (ZEN) was detected in 100% of vegan urine samples but only 52% of omnivore samples, demonstrating distinct mycotoxin exposure patterns between dietary groups.
Vegans in the 2026 study consumed significantly more whole grains than omnivores (52 vs. 22 grams per day) while maintaining similar total cereal intake, yet did not show elevated overall mycotoxin exposure.
The Quick Take
- What they studied: Whether people who eat only plants (vegans) are exposed to more mold toxins than people who eat meat and plants (omnivores)
- Who participated: 218 people from Iceland—47 vegans and 171 omnivores—aged 23 to 64 years old. Researchers measured what they ate over two days and tested their urine for four types of mold toxins
- Key finding: Vegans were not more exposed to mold toxins overall. In fact, vegans had about 10 times less of one major toxin (OTA) in their bodies compared to meat-eaters, though they had slightly more of another toxin (ZEN)
- What it means for you: If you’re considering a vegan diet, you don’t need to worry that you’ll be exposed to more mold toxins than meat-eaters. However, all people should be aware that mold toxins exist in plant foods—this isn’t unique to vegans
The Research Details
This was a cross-sectional study, which means researchers took a snapshot of two groups at one point in time rather than following them over months or years. The researchers recruited 47 vegans and 171 omnivores from Iceland and asked them to record everything they ate over two separate 24-hour periods. This gave a detailed picture of their typical diet.
To measure mold toxin exposure, the scientists collected urine samples from all participants and tested them for four different mycotoxins: T2 toxin, DON (deoxynivalenol), OTA (ochratoxin A), and ZEN (zearalenone). These are real toxins produced by molds that grow on grains, cereals, and other plant foods. By measuring these toxins in urine, researchers could see what people had actually been exposed to through their diet.
The researchers then compared the toxin levels between vegans and omnivores and looked for connections between what people ate and the toxin levels in their bodies.
This research approach is important because it directly tests a concern that many people have: that switching to a plant-based diet might expose you to more harmful mold toxins. By measuring actual toxin exposure in real people rather than just guessing, the study provides solid evidence about whether this worry is justified. The study also shows how different diets lead to different patterns of exposure, which helps us understand the real-world health impacts of dietary choices.
This study has some strengths: it measured actual toxin exposure in urine rather than just estimating it from food, and it compared two real groups with different diets. However, the study has limitations worth knowing about. The vegan group was smaller (47 people) than the omnivore group (171 people), which could affect results. The study only looked at people in Iceland, so results might be different in other countries with different foods and farming practices. Also, researchers only measured diet for two days, which might not represent what people eat over months or years. Finally, the study is observational, meaning it shows associations but can’t prove that diet directly causes the toxin exposure patterns observed.
What the Results Show
The main finding was surprising: vegans were not more exposed to mold toxins overall, contrary to what some people had hypothesized. When researchers looked at DON (a common mold toxin found in grains), they found nearly identical levels in vegans and omnivores—1.84 nanograms per gram of creatinine in vegans versus 2.04 in omnivores. This difference was not statistically significant, meaning it could easily be due to chance.
However, the two groups showed very different patterns for other toxins. For OTA (another mold toxin), vegans had dramatically lower exposure—about 10 times less than omnivores. The median level in vegans was 0.01 compared to 0.11 in omnivores. This was a highly significant difference. Interestingly, for ZEN (yet another mold toxin), the pattern reversed: all vegan samples contained detectable ZEN, while only 52% of omnivore samples did.
These distinct patterns likely reflect the different foods each group eats. Vegans eat more whole grains and plant-based alternatives, while omnivores eat animal products that may accumulate certain toxins differently. The researchers found only weak correlations between cereal and rice consumption and toxin levels, suggesting that the relationship between diet and mold toxin exposure is complex and not straightforward.
The study revealed that vegans consumed similar amounts of total cereals as omnivores (214 grams per day for vegans versus 182 grams for omnivores), but vegans ate significantly more whole grains (52 grams versus 22 grams). This higher whole grain intake didn’t translate to higher overall mold toxin exposure, which is reassuring. The detection rates also varied: DON was found in 100% of omnivore samples but only 99% of vegan samples, while OTA was detected in 77% of vegan samples but 100% of omnivore samples. These differences suggest that food sources and processing methods matter significantly in determining which toxins people are exposed to.
This study directly addresses a hypothesis that had been suggested but rarely tested: that vegans might face higher mold toxin exposure due to eating more plant-based foods. According to Gram Research analysis, this is one of the first studies to directly measure mycotoxin exposure in vegans versus omnivores using biological samples. Previous research had mostly focused on toxin levels in foods themselves rather than actual human exposure. This study fills an important gap by showing that theoretical concerns about vegan diets and mold toxins don’t match what actually happens in people’s bodies.
Several important limitations should be considered. First, the vegan group was much smaller (47 people) than the omnivore group (171 people), which could make it harder to detect differences if they exist. Second, this study only included people from Iceland, so the results might not apply to vegans and omnivores in other countries with different foods, farming practices, and food storage methods. Third, researchers only measured diet for two days, which might not represent typical eating patterns over longer periods. Fourth, the study is observational, meaning it shows associations between diet and toxin exposure but cannot prove that diet directly causes these patterns. Finally, the study didn’t measure all possible mold toxins, so there could be other toxins not included in this analysis.
The Bottom Line
Based on this research, there is no evidence that switching to a vegan diet will increase your exposure to mold toxins. In fact, vegans in this study had significantly lower exposure to one major toxin (OTA). However, this doesn’t mean mold toxins aren’t a concern—they exist in plant foods for everyone. To minimize exposure, all people should: store grains and nuts properly in cool, dry places; buy from reputable sources; and vary the types of grains and plant foods they eat. These recommendations apply equally to vegans and omnivores.
This research is relevant to anyone considering switching to a vegan or plant-based diet who worries about mold toxin exposure. It’s also important for people with mold sensitivities or compromised immune systems. However, the study was conducted in Iceland, so people in other regions with different climates and food sources should be cautious about applying these results directly. People with specific health conditions should consult their doctor about dietary changes.
If you switch to a vegan diet, you won’t see immediate changes in mold toxin exposure—the body takes time to adjust to new dietary patterns. Based on this study’s measurement of urine toxins, changes in exposure would likely be detectable within weeks to months as your body processes different foods. However, long-term health effects from mold toxin exposure (or lack thereof) would take much longer to observe and would require ongoing monitoring.
Frequently Asked Questions
Are vegans exposed to more mold toxins than people who eat meat?
No. A 2026 study of 218 Icelandic adults found vegans had similar or lower mold toxin exposure than omnivores. Vegans actually had 10 times less of one major toxin (OTA) in their bodies, though exposure patterns differed between groups.
What mold toxins are found in plant-based foods?
Four main mold toxins studied were DON, OTA, ZEN, and T2 toxin. These naturally occur on grains, cereals, nuts, and seeds when mold grows on them. All people—vegan or not—are exposed to these toxins through plant foods.
Should I worry about mycotoxins if I switch to a vegan diet?
No more than omnivores should worry. The 2026 research shows vegans don’t face higher overall mold toxin exposure. All people can reduce exposure by storing grains properly in cool, dry places and eating a variety of plant foods.
Do whole grains have more mold toxins than refined grains?
The study didn’t directly compare whole versus refined grains for toxin content. However, vegans ate more whole grains but didn’t have higher overall mold toxin exposure, suggesting whole grain consumption alone doesn’t increase risk.
How can I reduce my exposure to mold toxins in food?
Store grains, nuts, and seeds in cool, dry places; buy from reputable sources; check expiration dates; and eat a variety of plant foods. These practices apply to everyone regardless of diet type and help minimize mold toxin exposure.
Want to Apply This Research?
- Track daily grain and cereal intake (in grams) along with type (refined vs. whole grain). Log weekly urine color and clarity as a simple proxy for hydration and kidney function, since mycotoxins are measured in urine. Note any digestive symptoms or food quality concerns.
- If switching to a plant-based diet, use the app to log your grain sources and storage practices. Set reminders to check expiration dates on nuts, seeds, and grains monthly. Track which specific plant-based foods you eat to identify patterns and ensure dietary variety, which reduces exposure to any single food’s potential toxins.
- Over 3-6 months, track changes in your diet composition (percentage of whole grains, variety of plant sources, and storage practices). Create a baseline of your typical weekly grain consumption, then monitor for consistency. If you have access to urine testing through your healthcare provider, periodic testing could show actual toxin exposure changes, though this is not necessary for most people.
This research provides important information about mold toxin exposure in vegans versus omnivores, but it should not replace personalized medical advice. The study was conducted in Iceland and may not apply to all populations or climates. If you have specific health concerns about mold toxin exposure, food allergies, or are considering major dietary changes, consult with a healthcare provider or registered dietitian. This article is for informational purposes only and does not constitute medical advice. Individual responses to dietary changes vary, and what applies to the Icelandic population may differ in other regions with different food sources and storage conditions.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.