Are there mycotoxins in your food or coffee?

In this month’s blog I’m answering everyone’s most common question: “Are there mycotoxins in my food?” The short answer is yes, but a lot of food has lesser amounts of mycotoxins. The United States and European Union both have stringent limits on mycotoxins allowed in food. Because the limit on mycotoxin contaminated foods isn’t zero, this leads to most everyone having some small number of mycotoxins in their urine, which can be seen in the urine mycotoxin tests available. In toxicology, the quote “The dose makes the poison” is often used, which is a paraphrase from the Swiss physician and chemist Paracelsus that means anything can be a poison depending on the amount of exposure. This means that it really isn’t important whether you are being exposed to mycotoxins (you are), but to what extent are you being exposed.

The sources of toxins that have been measured are Ochratoxin A (OTA) from Aspergillus and Penicillium and toxins from Alternaria. The European Commission assessed which foods were leading to small amounts of OTA exposure. The report indicated that cereals, coffee, beer, wine, cocoa, dried fruits, meat, and spices were the most significant sources of OTA. In that report they estimated that 10% of the OTA intake was from coffee¹. Alternaria produces five different toxins: Altenuene, Alternariol, Alternariol monomethylether, Tentoxin, and Tenuazonic Acid. These have been seen in similar products as the ones discussed above². As of June 2019, there was no regulation of Alternaria toxins in foodstuffs, however, maximum levels were under consideration. 

Since coffee seems to be the biggest source of mycotoxins, the questions include 1) Do mycotoxins break down in coffee, 2) How much mycotoxins have been found in coffee, 3) Does the source of origin of the coffee matter, and 4) Do coffee drinkers have more mycotoxins than in their body than non-coffee drinkers? 

Most food items are processed in some manner before they are consumed.  This can include baking, roasting, or frying, which can affect the chemical structure and concentration of mycotoxins in the final product. For OTA, reports of how it is affected by these processes have ranged from no impact to almost a 100% reduction³. In several studies, OTA has been shown to decrease in roasted coffee^4,5. Another study from Sueck et al. shows that, in high temperatures, OTA can be broken down (Figure 1)⁶. This data indicates that coffee that is roasted at higher temperatures could have less OTA.    

One of the most comprehensive studies of looking at mycotoxins in coffee is from Mujahid et al. in 2020⁷. They looked at Alternaria toxins from multiple different countries to see if they could find any toxins. As seen in Table 1, they all looked at 78 coffee brands from over a dozen countries. A considerable number of these fell below the limit of detection (LOD), which indicates that there weren’t many mycotoxins in these samples. This data is further summarized in Table 2. The caveat to this data is that they were looking at Alternaria toxins and no other mold toxins. However, as stated above, the foods contaminated with Alternaria toxins have a significant overlap with foods contaminated with Penicillium and Aspergillus.  

If we wanted to discount the data from Mujahid et al. and look further into OTA exposure through coffee, we could look at a paper from Cramer et al. published in 2015⁸. This lab measured OTA in the blood of booth females and males. They also looked at both coffee drinkers and non-coffee drinkers. The take home message for me is seen in Table 3, where you can see the same mean value of OTA in both coffee drinkers and non-coffee drinkers. If there was any significant contribution of OTA to patients that drink coffee, you would expect a slight increase in this value, even if it were not significant.  However, no increase at all is interesting and indicates to me that coffee is not a substantial contributor of mycotoxins to people. 

I have very limited data on this subject; however, I will talk about a small pilot study that Neil Nathan, MD, and I ran a couple of years back. We had 10 participants abstain from foods known to be high in mycotoxins (the list is below) and then we tested their urine mycotoxins. We then had them consume large amounts of these foods for a couple of weeks and then retested. We did not see any significant increase in mycotoxins. This is obviously a small sample size, and I would probably have monitored the diets more if we were going to publish, but this was an interesting, small experiment. 

 I hope this blog is helpful to people. I think this further highlights an item frequently spoken about, and that is: What is the biggest source of mycotoxins in patients? I continually return to the fact that most mold problems come from indoor environmental exposure in a home, workplace, school, etc. I’m not saying these small amounts found in food could not be problematic for patients that already have mold issues. But because their detox systems have been impaired and glutathione storage is used up, these tiny amounts could have detrimental effects. 

1.            Commission, E. Assessment of dietary intake of ochratoxin A by the population of EU Member States. (ed. Protection, D.-G.H.a.C.) (https://ec.europa.eu/food/sites/food/files/safety/docs/cs_contaminants_catalogue_ochratoxin_task_3-2-7_en.pdf, 2002).

2.            Chain, E.P.o.C.i.t.F. Scientific Opinion on the risks for animal and public health related to the presence of Alternaria toxins in feed and food. EFSA Journal 9, 2407 (2011).

3.            Scudamore, K.A., Banks, J.N. & Guy, R.C. Fate of ochratoxin A in the processing of whole wheat grain during extrusion. Food Addit Contam 21, 488-97 (2004).

4.            Blanc, M., Pittet, A., Munoz-Box, R. & Viani, R. Behavior of Ochratoxin A during Green Coffee Roasting and Soluble Coffee Manufacture. J Agric Food Chem 46, 673-675 (1998).

5.            Suarez-Quiroz, M. et al. Effect of the post-harvest processing procedure on OTA occurrence in artificially contaminated coffee. Int J Food Microbiol 103, 339-45 (2005).

6.            Sueck, F. et al. Occurrence of the Ochratoxin A Degradation Product 2’R-Ochratoxin A in Coffee and Other Food: An Update. Toxins (Basel) 11(2019).

7.            Mujahid, C. et al. Levels of Alternaria Toxins in Selected Food Commodities Including Green Coffee. Toxins (Basel) 12(2020).

8.            Cramer, B. et al. Biomonitoring using dried blood spots: detection of ochratoxin A and its degradation product 2’R-ochratoxin A in blood from coffee drinkers. Mol Nutr Food Res 59, 1837-43 (2015).