10 Sneaky Sources of Mold in Your Diet

Don't let "fresh" food make you sick.

January 22, 2016
apple mold

You know mold when it's staring you right in the face: white and green fuzzy stuff sitting on top of your week-old leftovers. But even if you diligently clean out your fridge, you may still be eating mold, and more importantly, mold toxins, without even realizing it. Not because your food has gone bad on your shelf, but because it was produced that way.

More: 50 Foods You May Not Need to Refrigerate

"Most people are exposed to chronic low doses of mold toxins in every single meal, but they are invisible and particularly hard to identify," says Dave Asprey, author of The Bulletproof Diet. "The more mold toxins you eat, the more damage they do over time."

Since not all food is equally moldy, Asprey shares the foods that should be avoided and others that you can still enjoy, as long as you use a discerning eye.

coffee beans

There are so many benefits of coffee; too bad so many of them are undone by the fact that coffee beans can be moldy.

"Mold is such a problem in coffee that governments around the world—from the European Union to South Korea and Japan—have instituted safe limits for one of the mold toxins in coffee in the parts per billion levels," says Asprey. "The United States and Canada, however, have no established limits, resulting in a much higher chance of your cup containing enough mold toxins to influence your performance or even your health."

Asprey says that cheap coffee and decaf coffee tend to have more mold than high-quality beans, while "wet-processed" coffees can have less mold. 

chocolate truffles

Don't worry, we're not about to tell you to avoid chocolate. In fact, the opposite is true. "Very dark chocolate itself is actually quite healthy," says Asprey. "Chocolate is full of polyphenol antioxidants that fight free radicals, and it has a mild amount of caffeine to enhance performance."

That said, Asprey explains that chocolate is produced in a fermenting process, so mold is extremely common, and could be one of the many chocolate mistakes you're making. "Choose your chocolate wisely; make sure it's at least 85 percent dark chocolate, and enjoy," he says. "I almost always take coconut charcoal with chocolate to bind some of the mold toxins—mold in chocolate is at least as common as it is in coffee.

corn on the cob

"Corn is nearly universally contaminated, as it grows with a known toxin-forming mold called fusarium," says Asprey. What's worse is that, when exposed to herbicides like Roundup, the agricultural mold becomes more toxic. 

We all know that high-fructoce corn syrup is bad for your heart, but a partial solution is to go organic. While organic corn can still have mold, it's less toxic because it hasn't been exposed to herbicides. "Corn is still a pretty high-risk food, but it's better than most other grains as long as it's organic," says Asprey. "Get it frozen, or when corn is in season. Buy it from a farmer the same day it's picked."

meat steak preparation

"You are not only what you eat, but also what your food ate," says Asprey. The grain and corn used for animal feed are even moldier than the grains and corn that humans eat. As animals eat moldy foods, the toxins accumulate in their fat, leading to toxic meat, and it's no shock then that there are tons of germs hiding our in your supermarket meat.

Instead, opt for organic and grass-fed meat. "Organic, grass-fed meat provides more nutrients and fewer toxins than grain-fed conventional meat, with more antioxidants, omega-3s, trace minerals, and vitamins than any other food," he says.

cheese board

Dairy has a similar problem to meat's, but it's amplified by casein, the dairy protein. "Casein concentrates mold toxins," says Asprey, "but cheese is even more problematic than milk because the very process that turns milk into cheese also promotes the buildup of toxins." Cheese is literally a concoction of dairy and fungi, so it's unsurprising that mold toxins are found in more than 40 percent of conventionally produced cheese. 

While you're better off avoiding most dairy, butter and ghee are the exceptions, adn these 14 healthiest cheeses might be your best bets. "Less than 2 percent of conventional butter is contaminated with mold toxins," says Asprey, because casein is largely absent from butter. But to really get the biggest bang and lowest mold, you have to go for grass-fed butter, which is high in vitamin A, K2, D, and E.

pepper mill

"Despite being one of the most common spices, studies have shown that black pepper tends to be especially high in mold toxins, particularly aflatoxin and ochratoxin A," says Asprey. He says either giving it up all together or at least ditching ground pepper. "A good pepper grinder with fresh, high-end black pepper is the only way to do it."


"Cantaloupes are extremely high in sugar and are one of the moldiest fruits in the world, so unless you've got a freshly cut, perfectly ripe, unblemished one, it's worth skipping," says Asprey. The fruit has been historically tied to listeria outbreaks, so stay knowledgeable about any possible recalls and contaminations. 


All nuts (except for coconuts) are suspect for mold: Brazil nuts, pistachios, pine nuts, walnuts, pecans, hazelnuts, and cashews are some of the worst offenders, even though they're some of the healthiest fats for weight loss. The one nut to absolutely avoid, however, isn't actually a nut. Peanuts are legumes, not nuts, but they are common carriers of aflatoxin (a type of mold toxin).

While peanuts are the only "nuts" on the absolute don't list, still use caution when browsing other types. "I recommend buying whole nuts with the skin (not shell) still on, as manufacturers use damaged nuts that are far more likely to contain mold toxins to make slivered, chopped, or ground nuts, nut butters, and nut flours," says Asprey.

milk varieties
Milk Alternatives

"Nut milks have the same problems as nuts, but are often worse because the bottled nut milks are made from nuts that are too ugly to sell," says Asprey. He explains that "ugly" nuts are usually damaged, which leaves them wide open to mold contamination. 

Follow our guide to milk alternatives to better understand which to choose in the store, and remember that even soy milk faces the same problem, since it's often made from low quality soy. "There are nine kinds of toxin-forming fungi that impact soy crops in the United States alone," he adds. 

If you're looking for an alternative to cow's milk, Asprey recommends diluted coconut milk as a safe choice. Whatever you pick, just make sure it doesn't contain carrageenan.

vinegar varieties

"Red wine vinegar, malt vinegar, and balsamic vinegar tend to be highest in mold toxins," says Asprey. Remember that vinegar has many uses around the home, if you use the right type. The exception to the do-not-use rule: apple cider vinegar.

"One study found that 20 grams of apple cider vinegar reduces glucose levels and insulin sensitivity after a meal in both insulin-resistant and healthy people," he says.

See Next