Vegetarianism has been on the rise for years; in 2024, 2.3 million Canadians self-identified as vegetarian, a 176 per cent increase from 2015. Several factors contribute to the marked rise, including vegetarianism’s perceived benefits for both individual consumers and the environment. But how beneficial is it really? McGill Professor of Animal Science, Surgio Burgos, and his former PhD student, Olivia Auclair—a postdoctoral researcher at Oxford University’s Environmental Change Institute—worked to determine the benefits of transitioning towards, or entirely to, a vegetarian diet.

“First, we looked at the contribution of important foods, which we call ‘livestock produce products,’ whether that be meat, red meat, white meat, or dairy foods, and the contribution to nutrients,” Burgos said in an interview with The Tribune. “[We] then looked at the environmental impact [of these foods] through greenhouse gas emissions [….] [Then we] put the information that we had gained for Canada in the context of other countries.”

In their recent review paper, Burgos and Auclair aimed to further elucidate the consequences of switching from animal-based protein to plant-based protein, analyzing nutritional, environmental, and health impacts of complete and partial dietary substitutions.

“Basically, we found that there were co-benefits of substituting red and processed meat with plant protein foods across all three of the dimensions that we looked at, so nutrition, environment and also health,” Auclair said in an interview with The Tribune. “So that’s good news, and we saw that for total replacements, where 100 per cent of red and processed meat was substituted. But we also saw, obviously smaller, but similar co-benefits when simulations were partial substitutions, so 50 per cent of red and processed meat.”

Their study found that substituting animal-based protein with plant-based protein sources led to average increases in calcium, iron, fibre, and potassium intake, as well as decreased levels of saturated fats. They, however, noted that their results were highly influenced by governmental policy. 

“For example, in the Netherlands, they don’t supplement [cow] milk with vitamin D, but we do [in Canada], it is mandatory. In the U.S., it is optional. So that vitamin D outcome changes because of [those policies],” Burgos said.

This illustrates the impact of policy on nutritional levels; the nutritional benefits of switching from animal to plant-based products are dependent upon which sources are fortified. Fortifying plant-based protein alternatives is critical to cementing the benefits of transitioning towards a plant-based diet.

Along with vitamin D, vitamin A, calcium, and iodine levels appear to have been particularly dependent on fortification policy.

“So for me, the goal of the study is to inform public policy in dietary guidance [and plant-based alternative fortification],” Burgos said. “Some countries include environmental impact as part of the considerations that they have to guide dietary guidance [….] But food fortification is another aspect of it.”

Another key finding of the study is that substituting meat with plant-based alternatives yields greater benefits than dairy substitutions.

“We’re sort of seeing there’s no clear co-benefits from substituting dairy. You get trade-offs with certain nutrients, you don’t see as big of reductions to diet-related greenhouse gas emissions, and the health gains that we saw in the dairy scenarios were only because of this increase in plant-based foods that accompany the reduction in dairy,” Auclair said. 

The research highlights the importance of choice in dietary substitutions. While the study shows that opting for plant-based alternatives can have positive environmental, nutritional, and health-based impacts, policy plays a huge role in the nutritional benefits of these substitutions. Their findings also reveal that changes don’t need to be extreme to have a real impact; substituting meat with plant-based alternatives, even just once a week, can benefit both your health and the environment.

“I think, for me, it’s not so much like telling people to eat a specific way, like ‘You should do this dietary pattern, or this dietary pattern,’ it’s really about just making more conscious food choices,” Auclair said. “And like Sergio said, like a few nights a week, integrating [plants], instead of cooking something with red meat, just try a new recipe [….] It’s about those individual choices that you make every day.”