Ask a Scientist

Courtesy of The University of Tennessee, Knoxville.

Ah, meat in a jar. One day you’ve got basically nothing worth eating - just some cells and nutrients scattered randomly throughout a matrix of proteins, carbohydrates, cellulose, or other flavorless macromolecules - and the next you have a perfected crafted matrix of tissues that is virtually indistinguishable from the real deal. 

Basically, instead of raising and killing animals for food, we can just grow meat. You know, in a jar. Or a container of your choice really. No need to painstakingly raise and kill our buddies out in the pastures anymore. Sounds appetizing, right?

Well, probably not at first. A lot of the foods that we eat are the product of microbial activity, from breads, sauces, and beverages (beer!), but most people don’t usually equate “made in a lab” with “tasty” or “safe.” Naturally, the idea of growing meat in a jar isn’t going to resonate with everyone immediately. So, is this really a thing – and if it is, why would anyone want to eat this instead of the real deal right from the animal?

Well, the answer is that livestock are an incredibly inefficient food source. Growing animals for food takes up a bunch of resources, most notably because they need their own food. One study conducted in 2013 found that36% of all crops grown around the globe are used for feeding animals and only 12% was used for human consumption. In the US, the numbers are even more skewed, as even more of the crops produced here are used for animal raising than in other parts of the world. Regardless of the ethical dilemma, the results are pretty clear: animals eat a lot of food – food that we could be eating instead; that whole process wastes energy.

So, how much energy are we talking about? Well, the Institute of Electrical and Electronics Engineers (IEEE) published a recent diagram illustrating just how much net energy a variety of foods require to go from farm to table, and the results might surprise you.Beef, for instance, was almost nine times more energy intensive to create than apples or soy beans.However, plants weren’t always low-energy foods either, as tropical fruit allegedly required more energy than every category, including beef. It’s not a perfect figure – it’s missing some key crops like wheat and corn. However, if that isn’t convincing enough, a recent study published in Science analyzed the energy and mitigation strategies of various agricultural products across tens of thousands of farms. What did the results show? The first author of the study, Joseph Poore, was quoted in an article written in The Guardianin reflection of the findings, and suggested that, “A vegan diet is probably the single biggest way to reduce your impact on planet Earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use.” Nothing sugar-coated about that, huh?

Okay, so, if we want to curb their appetite for energy (pun intended), we should just stop eating animals, right? Well, if you’re like most Americans, that idea sends you running for the hills. But we could make a synthetic substitute – one that has all of the properties of real meat, but is grown in a more energy-efficient way. Like in a jar or a container of your choice. Behold: Meat in a jar, more technically known as cultured meat.

This seems like a great solution at first. We get to keep all of the benefits of eating meat without the environmental impacts and energy consumption, great! But hold on, where are we on the technology? Are we actually growing this stuff commercially? Well, sort of. The first cultured meat product, a burger patty, wasdemoed in 2013to a panel with pretty decent commentary. Notably, commentators suggested that the product lacked the fat traditionally associated with a burger.

Which really opens a can of worms on how complex this whole growing meat in a jar thing really is. Meat as we know it isn’t just an arbitrary cluster of “meat” cells. There are all sorts of different cells in meat. Nerve, muscle, connective, and epithelium are the four types of tissues found in all meat products, and you need all of them to really replicate the good stuff. For ground beef, that might be less challenging, as the organization of these tissues isn’t super important, you just need the right proportions. But what about non-ground products? Whole chicken breast or strip steaks for instance? Now the layers and organization of the tissues become important to texture and flavor. Constructing that tissue is much harder to do.

But scientists have made some great progress, so all is not lost. How are they growing meat right now? Well, cultured meat borrows a lot of elements from the more general field of “tissue engineering.” Tissue engineering isn’t limited to food products, many of its desired applications are for creating tissues for medical reasons. Skin grafts, tissue grafts for organs, perhaps entirely new organs for transplants all benefit from the knowledge and research done in tissue engineering.

The premise for it is simple, even if there’s a lot to uncover in the details. First, you need starter cells that can transform into the right cells when activated. Stem cells immediately come to mind, and those cells could also be used for cultured meat. To get cells to grow, you need food for them as well. The culture is fed a host of different nutrients like proteins, vitamins, minerals, etc. in a growth medium to keep them alive and multiplying. Then, you need the cells to link up with one another. Growing a bunch of cells won’t provide any structure, so a structure has to be created. This scaffold, as it’s called in tissue engineering,can be made of a ton of different materials and can be made many different ways. Some are borrowed from other organisms, others can even be printed; ultimately the application dictates what scaffold is best.

So how close is this stuff to your grocery store? Well, it’s hard to tell for sure, but probably pretty close. Cultured meat is not available to consumers yet, but one report suggested that the cultured meat industry is slated to take off at any moment, gaining as much value as$20 million by 2027, with products being ready to roll out as early as this year. When this actually happens is still tentative, none of us at Ask a Scientist have a crystal ball. And there are some companies that are putting all of their effort into making cultured meat products. Ultimately, the evidence seems clear, this food should be on supermarket shelves within the decade. And we can’t wait to try it!

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