Most Food Should Not Be Fuzzy

In yesterday’s newsletter, we asked you for your policy when it comes to mold on food (aside from intentional mold, e.g. blue cheese etc), and the responses were interesting:

• About 49% said “throw the whole thing away no matter what it is; it is dangerous”
• About 24% said “cut the mold off and eat the rest of whatever it is”
• The remainder were divided equally between “eat it all; keep the immune system on its toes” and “cut the mold off bread, but moldy animal products are dangerous”

So what does the science say?

Some molds are safe to eat: True or False?

True! We don’t think this is contentious so we’ll not spend much time on it, but just for the sake of being methodical: foods that are supposed to have mold on, including many kinds of cheese and even some kinds of cured meat (salami is an example; that powdery coating is mold).

We could give a big list of safe and unsafe molds, but that would be a list of names and let’s face it, they don’t introduce themselves by name.

However! The litmus test of “is it safe to eat” is:

Did you acquire it with this mold already in place and exactly as expected and advertised?

• If so, it is safe to eat (unless you have an allergy or such)
• If not, it is almost certainly not safe to eat

(more on why, later)

The “sniff test” is a good way to tell if moldy food is bad: True or False?

False. Very false. Because of how the sense of smell works.

You may feel like smell is a way of knowing about something at a distance, but the only way you can smell something is if particles of it are physically connecting with your olfactory receptors inside you. Yes, that has unfortunate implications about bathroom smells, but for now, let’s keep our attention in the kitchen.

If you sniff a moldy item of food, you will now have its mold spores inside your respiratory system. You absolutely do not want them there.

If we cut off the mold, the rest is safe to eat: True or False?

True or False, depending on what it is:

• Hard vegetables (e.g carrots, cabbage), and hard cheeses (e.g. Gruyère, Gouda) – cut off with an inch margin, and it should be safe
• Soft vegetables (e.g. tomatoes, and any vegetables that were hard but are now soft after cooking) – discard entirely; it is unsafe
• Anything else – discard entirely; it is unsafe

The reason for this is because in the case of the hard products mentioned, the mycelium roots of the mold cannot penetrate far.

In the case of the soft products mentioned, the surface mold is “the tip of the iceberg”, and the mycelium roots, which you will not usually be able to see, will penetrate the rest of it.

“Anything else” seems like quite a sweeping statement, but fruits, soft cheeses, yogurt, liquids, jams and jellies, cooked grains and pasta, meats, and yes, bread, are all things where the roots can penetrate deeply and easily. Regardless of you only being able to see a small amount, the whole thing is probably moldy.

The USDA has a handy downloadable factsheet:

Molds On Food: Are They Dangerous?

Eating a little mold is good for the immune system: True or False?

False, generally. There are of course countless types of mold, but not only are many of them pathogenic (mycotoxins), but also, a food that has mold will usually also have pathogenic bacteria along with the mold.

See for example: Occurrence, Toxicity, and Analysis of Major Mycotoxins in Food

Food poisoning will never make you healthier.

But penicillin is safe to eat: True or False?

False, and also penicillin is not the mold on your bread (or other foods).

Penicillin, an antibiotic* molecule, is produced by some species of Penicillium sp., a mold. There are hundreds of known species of Penicillium sp., and most of them are toxic, usually in multiple ways. Take for example:

Penicillium roqueforti PR toxin gene cluster characterization

*it is also not healthy to consume antibiotics unless it is seriously necessary. Antibiotics will wipe out most of your gut’s “good bacteria”, leaving you vulnerable. People have died from C. diff infections for this reason. So obviously, if you really need to take antibiotics, take them as directed, but if not, don’t.

See also: Four Ways Antibiotics Can Kill You

One last thing…

It may be that someone reading this is thinking “I’ve eaten plenty of mold, and I’m fine”. Or perhaps someone you tell about this will say that.

But there are two reasons this logic is flawed:

• Survivorship bias (like people who smoke and live to 102; we just didn’t hear from the 99.9% of people who smoke and die early)
• Being unaware of illness is not being absent of illness. Anyone who’s had an alarming diagnosis of something that started a while ago will know this, of course. It’s also possible to be “low-level ill” often and get used to it as a baseline for health. It doesn’t mean it’s not harmful for you.

Stay safe!