The next time you sit down to a steak dinner or savor a juicy burger, take a moment to ponder the thought that the meat on your plate may have helped you to become the modern human you are today. While obtaining meat during prehistoric times may not have been as convenient as going to the neighborhood supermarket, meat has been a key part of human diets since we were hunter-gatherers.Before the development of agriculture, early humans scavenged carcasses and hunted wild animals. More calorie and nutrient rich than plants, meat is also a major source of protein and B vitamins. There is evidence that consuming meat and marrow from animals may have provided early humans with the resources to evolve a large brain. Yet despite all of its seeming benefits, more and more people are avoiding meat as a dietary staple.

The trouble with meat

There are several ethical, health, and environmental costs associated with modern agricultural practices and excessive meat consumption. Cattle reared for meat and dairy are often confined in cramped pens while battery farm chickens are kept in cages so small that they can barely spread their wings. Cattle are major contributors of methane — a greenhouse gas about 30 times more potent than CO2. Seafood may be tainted by heavy metals, while beef may be contaminated with harmful bacteria like E. coli during the slaughter process.Run-off and discharge containing antibiotics used to treat disease or bulk up farm animals also leads to the emergence of antibiotic resistant bacterial pathogens in the environment. According to Matt Ball, senior media relations specialist for The Good Food Institute (a global nonprofit working to advance the fields of plant-based and cell-based meat, eggs, and dairy), this widespread use of antibiotics on factory farms is leading to increasing numbers of antibiotic-resistant superbugs that already kill between 500,000 and 700,000 people a year.Increased consumption of red meat has also been linked to increased incidence of colorectal cancer and heart disease. Some religious groups also abstain from meat, as they support non-violence toward animals. More and more people are naming one -- or more -- of these reasons for abstaining from meat consumption. Yet many miss the feel and taste of meat, blowing the market for meat alternatives wide open. Enter “cultured meat.”

Cultured meat – healthier, ethically produced meat?

Cultured meat is, most simply, meat grown from animal cells rather than obtained from animals farmed with a single purpose: eventual death and arrival on someone’s dinner plate. To “grow” meat, stem cells are collected from animal muscle tissue and incubated in bioreactors, where they differentiate into muscle fibers that form tissue. In the case of steaks, the tissue is grown into the correct 3-D structure; in the case of other “meats,” like patties and nuggets, the tissue is harvested and molded into the correct shape.But -- since it comes from an animal, it’s still meat, right?Technically, yes -- but cultured meat (a.k.a., cell-based meat) has several important advantages over current animal agricultural practices.For example, one tissue sample from a cow can yield enough muscle tissue to make 80,000 quarter-pounder burgers. The number of whole cows needed for the equivalent number of patties is 80 -- and considering the environmental impact (land usage, water, methane release) associated with nearly 100 cows, it is easy to see how cultured meat is more sustainable.And while meat from animals poses several health risks, many if not all of those risks can be mitigated through cell-based meat. In a carefully controlled sterile facility, the need for antibiotics is reduced or eliminated, reducing the release of antibiotics into the environment. Says Ball, “Cell-based meat won’t require antibiotics, given that it will be produced in clean facilities. This is important because the vast majority of all antibiotics produced today are used by industrial animal agriculture.”Cell-based meat also does not come into direct contact with animals, eliminating contamination by pathogens found in the gut. “Cell-based meat has no intestines, so there are no feces and no fecal contamination,” explains Matt, “In their last test, Consumer Reports found bacterial contamination on 97% of chicken. We are told to handle raw chicken as though it was toxic waste, because, in a way, it is. Cell-based meat will change that.”By adjusting culture conditions, cultured meat can also be engineered to be healthier, with lower saturated fat and higher omega-3 fatty acid contents – which may help to reduce the risk of heart disease and certain cancers.

Will cultured meat bring change what it means to be vegetarian or vegan?

With greater consumer awareness of animal welfare, the toll that rearing animals for meat takes on the environment, and the demand for clean meat free from contaminants, cultured meat may become a widely accepted method of producing meat in the future. Healthier, friendlier, and more sustainable, could cell-based meat allow vegetarians and vegans to once again enjoy consuming meat?Responses from vegetarians and vegans reveal mixed reactions. Much of a person’s opinion about cell-based meat depends on their motivation for not consuming meat or animal-based products in the first place. Vegetarians may be more likely to embrace cultured meat than vegans, who avoid all animal-based products. Healthier versions of cell-based meat may encourage individuals who adopt a plant-based diet for health benefits to start eating meat. Cell-based meat could also be a welcome arrival for those who struggle to maintain a full nutritional profile on a vegetarian or vegan diet.But what about the issue of animal cruelty? Is cultured meat really friendlier to animals? The cells used to grow meat must be obtained from animals after all. Is the process painful to the animals? And what about Fetal Bovine Serum (FBS), a crucial component of the culture broth that typically comes from the blood of calf fetuses excised from slaughtered pregnant cows? The notion that cultured meat is not entirely “slaughter-free” or “cruelty-free” may be unacceptable to some.To address these issues, the clean meat industry is looking for non-animal alternatives. Memphis Meats has produced cell-based meat without FBS, and other clean meat companies have committed to producing cultured meat without FBS. Companies are also working to minimize animal suffering by establishing immortalized cell lines and developing sampling methods which do not cause significant pain to the animals.“It is important to note that every single clean meat company that we’ve worked with is motivated in part by a desire to end the use of animals for food,” says Ball. “I am confident they are working to make sure any animal involved is treated well, lives a good life, and experiences minimal discomfort from any cell sampling.”But cell-based meat isn’t the only solution to the issues associated with traditional animal agriculture. Several plant-based alternatives that mimic the mouthfeel, look, and taste of meat have already hit the shelves. You can get plant-based burgers that “bleed” like real meat from Impossible Foods or Beyond Meat, which recently saw one of the most successful IPOs of 2019. With plenty of plant-based options, why would vegetarians who miss or are curious about the experience of eating meat choose to consume cell-based meat, especially if enjoying these alternatives contradicts their vegetarian diet -- and the beliefs and values behind their dietary choices?

There is no straightforward answer

Cell-based meat has the potential to increase the benefits while concurrently minimizing the costs and harmful effects of meat consumption. However, our taste buds are ultimately shaped by a complex mixture of personal preferences, social norms, and belief and value systems. As the technology of producing cell-based meat evolves, so will our taste for it. There is no consensus as to whether vegans and vegetarians will sink their teeth into a cultured meat burger. It is up to the individual to decide if he or she will swap their usual tofu steak for one made of animal cells harvested from a bioreactor.When it comes to what we put in our mouths, we vote with our forks -- and only time will decide the ultimate winner. With the considerable number of non-vegetarians who are also interested in reducing animal cruelty and environmental impacts, it is possible that in the voting of the forks, cell-based meat and plant-based alternatives will both come out on top.Learn more about synthetic biology solutions to alternate proteins -- and other food and beverage needs -- at SynBioBeta 2019, October 1-3 in San Francisco, CA.