How Costly is Collagen?
This article was written by Mattea Kalpakoff, a student in my ENVECON 141 class this semester. One of the class assignments is to write a blog on environmental, climate, or energy challenges related to agriculture. I chose my two favorite submissions to publish here (it was hard to choose only two because there were so many excellent ones among the 156 students).
Mattea is a sophomore studying Environmental Economics and Policy with a minor in Theater, as she is passionate about using storytelling to drive effective climate solutions. She has spent the past year interning at a climate technology venture capital firm, and she plans to continue in climate VC, focusing on innovations that can revolutionize and decarbonize the agricultural sector.
In middle school, following the example of my emerging-environmentalist older sister, I swore off beef. I was told cows had the worst greenhouse gas emissions among livestock, and though I didn’t want to go vegetarian (I loved chicken empanadas too much), I wanted to take action to help our planet. My sister and I have continued not eating beef to this day, and we even roped my mom into our diet shift.
For years, I’ve been proud that my lifetime emissions were reduced, and I’ve loved adoring the cute cows dotting California fields without guilt because I wasn’t the cause of their slaughter. Only a month ago, I realized I may have been complicit in their murder all along.
One of my favorite sweet treats is a chocolate collagen powder that I mix in my non-dairy yogurt bowl every morning. It’s high in protein, low-carb, and delicious! I hooked many friends on it and even my grandpa, and we all agreed it was almost too good to be true. Because it was. I recently discovered that the powder has one simple ingredient: bovine hide collagen peptides. I’ve been eating cow skin every morning for years.
Horrified, I tried to research what percent of the lifetime emissions of cattle went to collagen to understand how much of their methane-riddled emissions I was inadvertently supporting with my collagen consumption. I found conflicting conclusions, revealing a currently debated subject among agricultural economists around how to measure the carbon footprints of livestock products. The emissions of one steer with 341 kg carcass weight are around 6,250 kg of CO₂e. This is equivalent to the emissions from driving 15,916 miles in an average gasoline-powered car.
Cattle produce multiple outputs—such as beef, hides, bones, and collagen—so determining the lifetime emissions of each product requires allocating cattle’s emissions to each product. However, methods of allocation vary, and each produces widely different results.
Collagen, as well as other non-meat carcass products like leather, are sometimes deemed byproducts, meaning they’re a sustainable utilization of otherwise wasted “leftovers” of meat and dairy production. I like that answer! However, these byproducts—encompassed in the non-beef categories of the figure above—account for about 5% of the total economic value per steer head. Given the small profit margins of the ranching competitive market, it’s likely that the revenue from these additional products keeps ranchers in business. Additionally, this recent study found that “neglecting co-product allocation leads to the systematic overestimation of the environmental impact of meat.” Thus, these non-meat products are more accurately co-products and should receive a share of cattle emissions.
But how should emissions be allocated? Using economic allocation based on relative market value, under the downstream assumption that 20% of the hide market is tied to collagen extraction, collagen accounts for over 5% of non-meat value, or 0.26% of total steer value. Allocation based on mass attributes 8% of live weight to hides (far greater than the 5% allocated to all coproducts under economic allocation), so the collagen share is around 1.6%. If you allocate based on protein share, collagen comprises 30% of the total protein mass in mammals.
Depending on the chosen allocation method, the share of beef steer lifecycle emissions attributable to collagen ranges from less than a percent to nearly a third of the total. To paint myself in the best light, I could simply decide that collagen is a byproduct, and my consumption sustainably reduces waste.
Organizations like the International Dairy Federation and OECD are trying to formalize an allocation framework that outlines which allocation method to use for different products. They conclude that revenue-generating co-products, like collagen, should use economic allocation, meaning collagen is only responsible for 0.26% of cattle emissions, or 16.25 CO₂e per cow, equivalent to the emissions from driving 41 miles.
But what about per serving of collagen? Each morning, I consume 20g of collagen, and each 700 kg live weight cow produces 11.2 kg of collagen under my previous assumptions. This leads to only 29 grams of CO₂e per serving attributable to cattle. Over a year, my daily habit results in 10.59 kg CO₂e annually from cattle, which is less than 0.17% of one cow’s lifecycle emissions and equivalent to driving 27 miles per year.
It’s important to note that these figures only include the emissions from cattle. Research on hydrolyzed bovine collagen shows that only 20% of the carbon footprint of collagen comes from agriculture, so the total carbon footprint of collagen is much larger. However, when focusing on the cattle emissions attributable to my collagen consumption, the answer appears to be negligible.
I spent hours researching different allocation frameworks and finding arguments for both my culpability and sainthood. The most disquieting fact is that, during the extensive time required to filter through the barrage of opinions, I grew overwhelmed by choice overload, and I kept eating my collagen. Easily understanding the carbon footprint of consumer products is not currently viable.
In an ideal, sustainable world, farmers would have efficient tools to measure their emissions. Accurate and clear allocation systems would allow every item in a grocery store to have an emissions label, akin to a price sticker. Then, customers could make educated choices, and there could be tax/subsidy systems to support lower-emission products. This would be a critical step in lowering global emissions. But that idyllic world is far from our reality.