Food for Thought
This is the first post in a series I’m calling Food for Thought where we’ll focus on how cultured meat will change the ways we grow, eat, and live together. In this series I’m less concerned about how cultured meat may come to be, if at all. Together we’ll explore just how our lives may change when cultured meat comes to market, for better or for worse. And we’ll come to conclusions about what we’ll need to do to shape the future we want, whether it includes cultured meat or not.
The year is 2025. You walk into your local supermarket. Fluorescent lights shine down on your cart, with its squeaky front wheel. Your eyes dart across shelves lined with brightly colored cereals and freshly misted produce, landing on the gleaming meat slicer behind the deli counter. But you’re not headed for the deli. Not today.
Instead you head to the back of the store, where the packaged cuts of meat call the chill of open refrigerated shelves home. Hermetically sealed in plastic, cuts of beef sit side by side in neat rows of juicy red muscle. Ground beef. Rib-eye. Filet mignon. You notice the standard labels: weight, price, manufacturer. Some labels read grass-fed, some hormone-free.
As you move down the fleshy fridge, your eyes dance between beef burgers and the plant-based alternatives on offer. Chickpea, soy, and pea protein. And near the end, you see something you’ve never seen before--a label that reads “Cultured meat.” What does it mean? They look just like all the other steaks on the shelf, you think to yourself. However, these steaks weren’t cut from a cow raised in a field or a factory. These steaks were grown in a lab.
Well, that’s not exactly true. They’ve been grown in specially outfitted food production plants, similar to those that ferment and brew beer. At least, that’s the goal many cellular agriculture start-ups have in mind. At the moment though, their operations are primarily still small ventures located in laboratories or pilot-scale food manufacturing facilities. For most of these cellular agriculture start-ups (companies growing products like milk, meat, and eggs without animals), their research is still focused on figuring out just how to turn a handful of animal cells into the meats we all know and love. That includes figuring out how to do that at large, industrial scales.
This may be the first time you’ve heard the words “Cultured meat.” Some of you may have heard people talk or write about “tissue engineered meat” or “clean meat” or “no kill meat” or “lab-grown meat” or even the dreaded “fake meat.” Some of these are more accurate descriptors than others. But generally, “cultured meat,” “cell-based meat,” or “cultivated meat” are the most appropriate terms to use for reasons you can find here and here.
But how does this even happen? How can you “grow” meat if you don’t first raise an animal?
1. Choosing the right type of cells to harvest
Before we can grow meat, we first need to collect cells. The hard part can be choosing just what kind of cells to harvest. Scientists can choose to extract primary cells, like muscle cells, directly from an animal’s mature tissue (a process that can be similar in many ways to how doctors take biopsies of warts, growths, or cancers from their human patients). These cells are great because we know what types of tissue they produce, and that gives us a better chance of controlling how that tissue develops. However, primary cells typically don’t survive long when removed from an animal’s body. At some point they just stop dividing. The aging cells have had enough, quit, and die. To avoid this problem, many scientists choose to harvest an animal’s stem cells.
Stem cells can be embryonic (collected from embryonic animal tissue) or mesenchymal (collected from an animal’s bone marrow or fat). Embryonic stem cells are wonderful because they can turn into any type of cell. They can be used for all types of applications, from regenerating hearts to regrowing neurons, and can theoretically live in culture forever. However, they are notoriously hard to stabilize and maintain. On the other hand, mesenchymal stem cells are much easier to culture and grow, but they differentiate into a much more limited array of cells: predominantly bone, cartilage, and fat. That’s just not enough to grow a steak.
Stem cells can also be created by “reprogramming” primary cells. This reprogramming restores their ability to divide and grow, turning them into embryonic-like cells. While induced pluripotent stem cells offer a promising alternative to obtaining stem cells that behave like embryonic cells without the need to destroy an embryo to get them, their use faces many challenges. Pluripotent stem cells are often unstable and difficult to reproducibly create. And a lack of reproducibility doesn’t particularly bode well for a cell-based meat company that wants to create high-quality food over and over again.
If you’re so inclined, you can read more about the benefits and challenges of using different cell types for cultured meat in this great summary created by the Good Food Institute. The good thing for animal lovers though: The majority of these extractions (barring the collection of embryonic stem cells) can happen while an animal is still alive.
Although cultured meat creators have many types of cells to choose from, the general process after each cell collection is relatively similar. Once removed from an animal, these cells are taken into the lab to screen and develop.
2. Screening and modifying cells in the lab
In the first stage of growing cultured meat, researchers allow their collected cells to grow and divide in the controlled environment of an incubator. They can test how the cells respond to guidance from chemical signals. They can characterize how different biomaterials impact whole meat tissue development. Researchers can subject their cells to group aerobics classes in the form of mechanical loading. These workouts are critical in guiding cells to mature into functional muscle cells. Just like people need to find out what type of exercise works best for the development of their bodies, scientists need to figure out what types of loading work best for the development of their cells’ tissues.
Cultured meat producers can see which cell lines grow the most efficiently across many different animals, and they can subsequently select those best for cultured meat production. Scientists can even insert new genes into their cells so that they produce their own growth factors, flavors, or other molecules that will help them grow into meat more successfully.
These cells will turn into meat by differentiating into the muscle, fat, and endothelial cells (the cells that form the walls of your blood vessels) that make up the combination of tissues we call meat. As it turns out though, trying to do this outside of a body is an extremely difficult process.
3. Growing meat tissues
Cell-based meat laboratories and start-ups have chosen many different strategies to overcome these challenges. Some companies create scaffolds that support the development of cells into full tissues, while others use their cells to grow individual food components that get combined later on. The former might be better suited for making entire pieces of meat, like cultured steaks, while the latter has been used to make products that have a less sophisticated structure, like chicken nuggets. For example, Eat Just’s chicken nugget is approximately “70% cultured chicken cells, with plant protein added for structure and flavour.” These chicken cells can be grown by themselves without developing the fat-muscle relationships seen in more complicated types of meat products.
To create tissue with more structure, researchers use a variety of materials and fabrication techniques. They build houses for cells to do their best work. Support structures, if you will, that allow cells to happily grow, manufacture proteins, and secrete extracellular matrix that will become the meat we eat. A handful of labs are using 3D-printing to fabricate tissue engineered constructs. The Parker Lab at Harvard electrospins tiny gelatin fibers, a process similar to the weaving of fine strands in a cotton candy machine. Some scientists have even grown muscle cells on cellulose scaffolds made from celery! From biodegradable polymers to animal-derived extracellular matrix, spinach to alginate hydrogels, the list of materials used to grow tissue goes on and on. I’ll leave it here for now, but you can learn more about tissue engineering in a more expansive article I wrote earlier this year.
So should you grab the package of “cultured meat” from the supermarket shelf instead of the beef you’ve been buying for years? Proponents of cellular agriculture argue you should for three reasons. They say cultured meat is better for the planet, better for animals, and, oftentimes, better for people. Made in efficient, closed-loop manufacturing facilities by skilled professionals in your own city, without the need to slaughter animals, cell-based meat has the potential to create an industry that will unload the burden modern livestock places on our environment while also making food production more ethical and more transparent.
The year is 2025. You’re standing in the supermarket, a package of shrink-wrapped cultured meat sitting in front of you, just within reach. You can imagine the cells turning into the full-bodied steak before your eyes, weaving muscle fibers, wrapping around the mouth-watering biosynthesized fat. One choice can wipe away the consequences of eating a food linked to so much animal suffering and environmental destruction. The choice seems so tantalizingly easy.
But what if cultured meat isn’t as sustainable as we hope it will be? More on that next time.
As always, check out more at my website, feel free to reach out with any comments or suggestions, and please share this with anyone who might enjoy it!