Feeding Our Future: A New Sustainable Option for Diversifying Our Diets

Sustainability Issue

By Gina Wynn

With the planet’s population at 7.7+ billion and growing, giving everyone access to a nutritious, protein-rich diet will only become more difficult in the years to come. Our current method of growing and distributing food is already taking a tremendous toll on the environment. And beef and other protein sources are often priced out of the reach of lower-income communities.

A team of Tufts University researchers have set out to tackle these problems. They’ve been working to develop a new alternative meat source with a low environmental impact that can be easily grown and distributed. It’s based on cultured caterpillar cells.

Natalie Rubio is leading the study with the help of team members Kyle D. Fish and David Kaplan, PhD, from the Biomedical Engineering Department and Barry A. Trimmer, PhD, from the Biology Department. The team received funding for the project through a New Harvest Cultured Tissue Fellowship.

As a long-time vegetarian, Rubio hopes her work with cultured cells will make an impact on the food system. “We’re producing food in a more efficient, more straightforward manner,” she said. “Because we don’t use animals, it’s also a lot better for the environment, it can have great impact on public health and food safety, and it has great benefits for animal welfare.”

Improvements to Agriculture

Rubio’s team is trying to improve upon both animal-based and plant-based food systems. In addition to compromising animal welfare, livestock farming produces significant global greenhouse gas emissions of methane and nitrous oxide from animal waste. Caring for cattle and providing land for herds to graze on depletes natural land and water resources. And rearing livestock uses valuable cropland to grow animal feed instead of food for humans.

There are more practical considerations as well, according to Rubio. “Conventional animal agriculture is very resource intensive because you are creating entire animals that are really complex … and then harvesting only specific parts, just their muscle and fat tissue.”

Plant-Based Boom

While plant-based alternatives to meat are less harmful to the environment, some argue that they lack the quality, complete proteins that humans need to build muscle and stay satiated. And one of those alternatives, the commonly used high-quality protein soy, has raised concerns about its potential side effects.

Impossible Foods, which uses soy in its Impossible Burger, addresses those concerns directly.

In the article “Soy: facts, myths and why it’s in our new recipe” on the company’s website, author Sue Klapholz, MD, PhD, vice president of nutrition and health, disputes assertions that “soy causes breast cancer, decreases male fertility, and interferes with thyroid function.”

Nevertheless, the market for plant-based food alternatives is certainly a strong one. The Impossible Burger that launched in 2016 already released a 2.0 version in 2019 that is now available in over 15,000 restaurants in the United States, Hong Kong, Macau, and Singapore, and in grocery stores in eight states.

Rubio agrees that plant-based products meet the needs of many people, but she believes in giving people options. “This isn’t a problem that needs one solution. I think having many alternatives for people to choose from that have different benefits is really important,” she said.

For some die-hard meat lovers, plant-based alternatives just don’t cut the mustard. According to Rubio, “Going plant based is a good solution, but most people still eat meat. It doesn’t satiate the desire for meat.”

A Fatty, Juicy Alternative

Rubio believes that with cultured caterpillar and other insect cells, she and her team have a good chance of being able to reproduce the savory, juicy taste and firm texture of meat that people enjoy. They’ve already had some success at manipulating the nutrition and texture of insect meat to mimic the muscular consistency of beef.

“What’s lacking is the less processed products. A lot of plant-based alternatives are ground meat substitutes, but there aren’t really any substitutes for steak or ‘natural’ whole cuts of meat,” said Rubio. “That’s something we see as being more achievable with cultured meat. Since it is actual skeletal muscle, it should look, taste, and feel exactly like whole cuts of meat from an animal.”

The key, according to Rubio, is fat. So far, her team has focused on cultured muscle cells, but now they are going to incorporate cultured fat cells into the research. The fat should bolster nutrition and add different properties to the products, the most important being juiciness.

Caterpillar Versus Cow Cells

Buy why not manipulate cow cells instead of caterpillar cells to achieve this goal? A team of scientists in the Netherlands led by Professor Mark Post of Maastricht University has already made progress in this area. In 2013, they created the first lab-grown hamburger made from stem cells — at a cost £215,000. But the price would decrease significantly once demand was established, Post told reporter Pallab Ghosh in the BBC News article “Team wants to sell lab grown meat in five years.”

“The number one challenge with cultured meat production right now is it’s difficult to produce large amounts of it and it’s very expensive to produce,” said Rubio. “Mammalian cells like cow, pig, and chicken cells are pretty picky about the environment they grow in. They need a specific temperature, a specific pH, and the right balance of nutrients and oxygen to grow really well.”

Rubio and her team find insect cells more suited to growth in a lab because they have different growth properties than mammalian cells. “They are more tolerant of their environment and can survive in a larger range of temperatures and pHs and with fewer nutrients,” said Rubio. “By using a different cell source, we can make the technology easier and cheaper to do.”

Scaling Up Locally

And scaling up caterpillar meat production would be more affordable as well. You just need a small colony of caterpillars to get started, according to Rubio, whose team harvests their colony’s eggs to isolate the embryonic cells. They then culture the cells to turn them into muscle and fat. They can keep them cultivated in the lab for a long time.

“The focus of scaling is inducing those cells to multiply in the right environment,” said Rubio. “Right now in the lab we do that on a pretty small scale — on the scale of milliliters of growth media, which is what we feed the cells.”

She envisions the process to be similar to the pharmaceutical industry’s use of cell cultures to produce therapeutics or beer breweries’ use of giant fermenters to produce alcohol from yeast. Large bioreactors or fermenters would enable cells to multiply in controlled environments. When the cells reached a sufficient density, they would collect the cells and process them into food products.

“It would be a huge savings of land and water in terms of environmental impact,” said Rubio. And such a process could be easily managed on a local level to provide low-cost meat alternatives to underserved communities.

Edible and Nutritious

But the team’s research isn’t quite at the stage where a product has been developed and is ready to go to market. As the only group focusing on culturing insect cells for food applications, they understand there is still much to learn. Rubio doesn’t know what challenges or regulatory hurdles her cultured meat product might face and if consumers would even be on board with it.

She speculates, however, that if people tried it, they would find her meat substitute “nothing too foreign.” When its cells are not manipulated, caterpillar meat is said to have a similar taste and texture to seafood like lobster and crab. But that is not the end goal. Rubio and team are working on the cellular level to influence the flavor and texture, so the finished product will be indistinguishable from meat.

“We’re not trying to introduce a new product [category],” said Rubio. “We’re looking to produce food items that look just like burgers, steaks, bacon, or chicken breasts.”

Essentially, the research team is just using a different cell source to produce the meat that people are already familiar with, just like how people use artificial crab instead of real crab in recipes to cut costs. Rubio explained that the species the meat comes from would be different, but it would still be edible, nutritious food — healthy for us, and vastly better for the health of our planet.