Grilled cheese sandwiches of death

new report in PNAS Nexus claims that making a grilled cheese sandwich exposes you to more tiny particles than a car exhaust. I know of no one who stands over a stove inhaling the aroma of burning cheese (or, for that matter, car exhaust); the study seems to be another way of destroying what little enjoyment we humans still have by inventing another reason to ban gas stoves.

“Combustion-related nanocluster aerosols”, or NCAs, is their term for whatever is produced when twelve public health officials, civil engineers, and chemists try to cook a grilled cheese sandwich. At least, that's what turned up in their brand-new high-resolution particle size magnifier-scanning mobility particle sizer, or PSMPS.^[1] Therefore, they reason, gas stoves must be banned.

Fig. 1. First attempt at reproducing their results. I'm beginning to see the problem here . . . .

These deadly NCAs are not “soot.” They are 10 to 100 times smaller than the average-sized virus (≈100 nm), and 250 times smaller than PM2.5 particles (2500 nm) thought to create problems from air pollution. These NCAs are even 20 times smaller than the particles in cigarette smoke that scatter blue light. They're roughly the size of a protein molecule. The authors say particles this small aren't routinely measured due to the deposition losses in measuring instruments and the low counting accuracy in counting particles smaller than 10 nanometers. Not surprisingly, their error terms are enormous.

Particles this small are more accurately called ultrafine smoke particles, which is great because you can report astro­nom­ic­ally large numbers of particles, which makes them sound really scary, and indeed the authors speculate freely about their possible health risk.

Whether they really believe this or whether it was just needed to get published is unknown. Since there were no controls for oven type, the study is useless for determing the risk, if any, from gas stoves. The authors' problem is that nobody would care about their main finding: burning toast on an electric stove creates fine smoke. (The sandwich in my experiment was cooked in an electric one. I can attest that it can produce copious amounts of smoke.)

I don't want to pick on these authors. I would have rejected any paper that doesn't do controls. It seems that they're becoming optional these days, especially for papers on controversial topics like microplastics and global warming. What they have in common is that they promote findings that the editors, and the peer reviewers they select, agree with.

To confirm their results, I tried making a grilled cheese sandwich myself following a recipe I found on the internet. Fig. 1 shows the result. My dead body, found next to the broken pieces of my smoke alarm—those things really need an Off switch—has been cropped from the photo.

Today it's toasty cheese sandwiches. Tomorrow, it'll be chocolate chip cookies. So far, people have tolerated it, but all bets are off if they try to ban bacon.

The purpose of the experiment seems to be to add more fuel to the phony furor about children supposedly 12.7% more likely to develop asthma when put in the same room with a gas stove, which I and many others have thoroughly debunked. But what it really shows is that cooking food without releasing clouds of smoke is an acquired skill.

The authors claim that buttermilk pancakes produce bigger but fewer particles that settled out quickly. Even so, it's probably best to turn on your exhaust fan and wear your gas mask when cooking them, just to be safe.

Other cheese-related food problems

This paper gets a "D−" on the Fippler scale, which means if I were a peer reviewer it would just scrape by with a recommendation for “Major Revision” (which is science jargon for “Do it over”). That's the same grade as the PNAS paper by environmentalists from the University of Oxford who created a table of 57,000 food products and reported that cheese has a “high impact“ on global warming.^[2] This result was based on a computer model that predicted the Global Warming Potential of various foods from a grocery store based on the ingredients list printed on the label. Unfortunately, their error bars showed the accuracy of their results to be so low as to make the results practically meaningless. Ironically, plant-based cheese alternatives were just as bad for global warming as real cheese.

According to Ayşe Erkmen et al.,^[3] deaths and illnesses from bad cheese were a big problem in the Ottoman Empire. Food poisoning tends to begin between 30 min and 72 hours after eating spoiled cheese, and about 420,000 people die from food poisoning each year. It was claimed in 1901 that producing cheese in tinned copper containers prevented cheese from going bad.

Over 92% of Chinese are lactose intolerant.^[4] So it's not surprising that many Chinese people think cheese is absolutely disgusting. Or at least, that's the impression they give when they find out that cheese is made by the action of bacteria (lactococci). Blue cheese is caused not by bacteria, but by a mold known as penicillium roqueforti. But the existence of Chinese rushan cheese, naizha cheese, and Tibetan yak cheese dispels the myth that Asians dislike cheese.

Animal rights activists think cheese not only causes global warming but is an animal product like eggs, so many of them would like to ban it. Unfortunately, the latest study on the microbiological aspects and rheological behavior of cheese—and something called cheese analogues ^[5]—is not really helping the reputation of fake cheese substitutes. Researchers are still struggling to make “soy cheese” ^[6] appear palatable. The problem seems to be that lipoxygenases (enzymes that oxidize polyun­sat­urat­ed fatty acids) in soy milk cause rancidity, and carrots have to be added to make the cheese-like product look more like cheese. Even so, as far as giving them a taste and structure. . . that is to say cheese-like sensory attributes . . . let's just say more research is needed.

Update (Mar 15, 2024): The New York Post has a scare article on this paper today. They quote the lead researcher as saying “After observing such high concentrations of nano-cluster aerosol during gas cooking, we can't ignore these nano-sized particles anymore.”

Did the reporter think to ask why the researcher didn't do any controls with another kind of oven? Did he ask whether the supposed particles were burned toast or something else? This study was junk science, but even the allegedly conservative press can't tell the difference.

mar 01 2024, 10:32 am. last updated mar 15, 2024, 4:07 pm