There are superfoods, and there are superfood fads. They come, and sometimes they go. One of the latest? Cockroach milk. Sound delish, doesn't it? It must be a hoax, or gimmick, or play on words, right?
Well, look at some of the most prestigious science news sources and you'll see it's no joke. In fact, there are those who assert that cockroach milk — yup, from the "brood sac" of the female Pacific beetle cockroach — may even be among the most nutritious substances on Earth. According to NPR's The Salt, cockroach milk is:
"Three times richer in calories than buffalo milk (the previous top contender for the most protein- and calorie-rich milk) ... So could a competitive health-food market that already stocks cow, goat, almond, soy, cashew, hemp, rice and coconut milk now see cockroach milk as the next superfood?"1
Apparently no other insect species is like this one. Scientifically designated as Diploptera punctate, this genus of cockroach is the only one known to be viviparous, i.e., to give birth to live young that developed in her body (as opposed to laying eggs), or to nurse her offspring. CNN notes:
"Like other viviparous creatures, this species of roach nourishes its growing embryos with a protein-rich liquid secreted by its brood sac — the roach version of a uterus. Soon after the embryo ingests the liquid, protein crystals develop within its midgut."2
The pale golden liquid from the crystals can, if one were interested, actually be extracted from the little beasts.
How Scientists Discovered You Really Can Milk a Cockroach
You may be wondering how this intriguing data first came available. It happened in a lab at the University of Iowa.
Professor emerita Barbara Stay had been studying the little critters and discovered that cockroach embryos, after a certain progression of development, were not only able to drink, but what they were drinking was nourishment from their female parental unit.
As the embryos' development advanced, the liquid they drank concentrated inside their guts and formed tiny crystals. On this nectar, cockroach babies of this species grow much larger than their ordinary cockroach counterparts.
The interesting thing is that if you dissect one of these creatures you'll find thousands of shimmering milk crystals, which under a microscope look like miniscule, gunmetal-hued shards of glass, vaguely shaped like squares. Fascinating.
In Stay's lab, the milk extraction process is pretty straightforward. According to Stay: "You substitute a filter paper in the brood sac for the embryos and you leave it there." Later, "you take it out and you get the milk."
Naturally, the protein crystals had to be studied, because the precise scientific makeup of cockroach milk and its potential nutritional attributes would be a fascinating thing to investigate.
In clinical studies, researchers found the milk crystal content rivaled some of the most nutritional attributes known to man. Leonard Chavas was one of the scientists as well as a co-author of the study, which was recently published in the journal International Union of Crystallography (IUCr).
"The protein crystals are milk for the cockroach infant. It is important for its growth and development," Chavas told CNN. "The interest here was, what's it really made of?"
Does Cockroach Milk Have Potential for Humans?
As The Salt conjectured, you could conceivably use cockroach milk as a milk substitute, just for the nutritional value.
It's hard to say whether this is good news or bad news, but as one of the researchers revealed (who lost a drinking game with fellow researchers and was required to give the brew a taste), cockroach crystal milk protein doesn't have that much flavor.
Subramanian Ramaswamy, Ph.D., a biochemist at the Institute for Stem Cell Biology and Regenerative Medicine in Bangalore, India, assessed the cockroach milk and observed, "In principle, it should be fine. But today we have no evidence that it is actually safe for human consumption."
Good to know. Research team member Sanchari Banerjee told the Times of India, "The crystals are like a complete food; they have proteins, fats and sugars. If you look into the protein sequences, they have all the essential amino acids."
A rich source of nutrients and calories, cockroach milk offers another promising advantage, according to Science Alert:
"Not only is the milk a dense source of calories and nutrients, it's also time released. As the protein in the milk is digested, the crystal releases more protein at an equivalent rate to continue the digestion.
'It's time-released food,' Ramaswamy said. 'If you need food that is calorifically high, that is time released and food that is complete. This is it.'"3
Cockroach Milk and Its Bioengineered Equal Could Potentially Feed the World
One of the reasons scientists are finding cockroach milk such a scintillating substance isn't just because it's unconventional (to say the least). Because a single one of those protein crystals has quadruple the nutrition value compared to cow's milk, it may in the future be tapped to feed the world.
Conjecture began in earnest when this possibility came to light. Ramaswamy's next project was to concoct a formula from genetically engineered (GE) yeast with a comparable nutritional profile to that of the protein crystals. Science Alert followed the process:
"An international team of scientists headed by researchers from the Institute of Stem Cell Biology and Regenerative Medicine in India decided to sequence the genes responsible for producing the milk protein crystals to see if they could somehow replicate them in the lab."4
One of the points researchers made regarding the potential boon to feeding the hungry with this protein source was that it won't likely be used for weight loss because of its density.
It probably wouldn't be useful in most industrialized areas of the world, either, as the average calorie intake, in the U.S. for example, is already too high.
However, as a food source for people without access to the food they need, cockroach milk and/or its GE yeast-derived equivalent could be tapped to relieve looming agricultural challenges globally. The long-term effects of this, of course, are completely unknown.
Liquid Harvest: Cockroach Crystal Milk Protein Extract
One interesting item to note is that cockroaches purportedly are so hardy, they've shown themselves to be impervious even to nuclear disaster, so the research might come in handy for future sustenance.
As a supplement, cockroach milk may very well find a place in the world, especially since researchers have nailed down the gene sequence to produce the milk protein crystals.
Currently, cockroach milk crystals are not being marketed, but Chavas and his team are working on how to extract it from the guts of the Diploptera punctuate embryos in order to reverse-bioengineer it and, as Chavas sees it, bring it to mass production.
Chavas, the scientist who found himself the taste-tester of the cockroach crystal infusion, said he could envision some sort of ice cream as a food variety. It wouldn't be much different from chocolate-covered grasshoppers and would have far more nutritional heft behind it.
First, though, as CNN notes, "they need to understand the exact biological and chemical mechanisms underlying the process."
Cockroaches Are Already Considered Food in Some Parts of the World
An adventurous traveler wrote of his visit to a cockroach farm in Jijan, China, where he met Wang, whose vision of changing the world to make it a better place involved a cockroach on every plate.
Wang farms (read: breeds) millions of American cockroaches — 10 million before harvest time — and sells them by the ton to Chinese pharmaceutical companies. According to CNN:
"They are usually ground and stuffed into pills and advertised as a cure for all manner of stomach, heart and liver ailments. In recent years, they have become a staple in Chinese medicine shops … promising wondrous results. Cockroach medicine is having something of a boom."5
Wang likes his fresh, though, although he also enjoys them fried, a crunchy fare that reportedly brings to mind an overcooked French fry with a not-so-pleasant aftertaste. The cockroach farmer declares they're easier to eat once their wings come off, and that he always feels better after he's started eating them. As just about anyone would surmise, it's probably all the protein.