U.S. And Canadian food labeling regulations may be poised for an update, potentially easing restrictions on protein claims for plant-based foods. A new article published in Current Developments in Nutrition argues that the current requirement to measure protein digestibility in rats to substantiate protein content claims disadvantages plant-based protein sources and raises ethical concerns.
The issue stems from inherent differences in how easily the human body breaks down plant versus animal proteins. Plant cell walls can physically impede digestive enzymes, and naturally occurring compounds within plant cells, known as antiproteases, can further hinder protein breakdown. Plant proteins often exhibit lower digestibility scores in laboratory settings compared to their animal-based counterparts.
Currently, in both the U.S. And Canada, manufacturers seeking to label a food as a “good source of protein” must not only report the total protein content but also calculate the “% Daily Value” based on both the amino acid profile and the protein’s digestibility. When digestibility data is unavailable – a common scenario for many plant proteins – regulations mandate testing in rats. This requirement, according to researchers at the Physicians Committee for Responsible Medicine (PCRM), creates an uneven playing field.
“Protein claims influence consumers’ choices at the point of purchase, but the current regulatory framework makes it less likely they will choose plant-based protein sources,” explains Joseph Manuppello, a research analyst at PCRM and lead author of the article. “It also raises ethical concerns for consumers who avoid both animal-based foods and products tested on animals.”
The authors contend that for most individuals, who generally consume adequate protein from a variety of sources, the sheer amount of protein per serving should be sufficient for labeling purposes. They propose that focusing on total protein content, rather than a potentially misleading digestibility score, would better align with current nutritional guidance and encourage the consumption of healthy plant-based protein sources like legumes, nuts, and seeds.
The article highlights the potential for alternative, animal-free methods to assess protein digestibility. Researchers identified two promising in vitro (test tube) methods that estimate digestibility by measuring pH changes as proteins are broken down by enzymes. The PCRM is planning to sponsor one of these methods through the U.S. Food and Drug Administration’s qualification program, aiming to establish it as an accepted alternative to animal testing.
This move towards in vitro testing could significantly reduce animal use. The authors note that thousands of foods with protein claims have entered the Canadian market in recent years alone, each potentially requiring rat-based digestibility testing under current regulations.
Beyond the ethical considerations, the PCRM argues that prioritizing protein quantity over digestibility is consistent with broader public health goals. “Protein deficiency is not a significant concern in North America, but diets high in saturated fat and low in fiber are,” says co-author Anna Herby, DHSc, RD, CDE, a nutrition education specialist at the Physicians Committee. “Removing barriers to plant-based foods making protein claims can help align consumer choices with a dietary pattern that supports health and reduces risks of chronic disease, like cardiovascular disease and type 2 diabetes.”
The current regulations aren’t universal. The article points out that Australia, New Zealand, the European Union, China, and South Korea primarily rely on protein amount to substantiate claims – an approach the authors believe better reflects modern nutrition science and fosters innovation in the plant-based protein sector.
The Physicians Committee for Responsible Medicine, founded in by Neal Barnard, MD, currently boasts nearly one million members, including over 17,000 physicians. The organization’s mission centers on promoting preventive medicine, conducting clinical research, and advocating for higher standards in research effectiveness, with a particular emphasis on non-animal research methods. According to their mission statement, the PCRM is dedicated to saving and improving human and animal lives through plant-based diets and ethical scientific research.
The proposed changes to protein labeling regulations represent a potential shift towards a more inclusive and scientifically sound approach, one that could encourage consumers to embrace the health benefits of plant-based protein sources without unnecessary ethical or regulatory hurdles.
