The most recent version of Canada’s Food Guide represents a paradigm shift in dietary recommendations, emphasizing the value of plant-based proteins while eliminating traditional food groups like dairy and meat. The complete effects of substituting plant-based foods for animal protein in Canadian diets are unknown, though.

There is strong evidence from recently conducted study at McGill University and the London School of Hygiene & Tropical Medicine that eating a diet largely composed of plant protein instead of animal protein can extend life and reduce greenhouse gas emissions. Crucially, it also implies that the advantages vary according to the kind of animal protein substituted.

The study, which was published in Nature Food, examined Canadians’ food records using information from a national nutrition survey. The study examined the effects of partially replacing (25% and 50%) red and processed meat or dairy with plant-based protein meals such as legumes, nuts, seeds, tofu, and fortified soy drinks on a range of outcomes related to climate change, health, and nutrition.

Tiny Dietary Adjustments Have a Significant Influence On Carbon Footprint

A recent study found that the main sources of diet-related greenhouse gas emissions in Canada are dairy and red and processed meat. This study indicated that substituting half of a person’s intake of plant-based protein meals for red and processed meats reduces that person’s diet-related carbon footprint by a staggering 25%. Dairy substitutes, however, exhibited less significant reductions of up to 5%.

Olivia Auclair, first author and recent PhD graduate of McGill’s Department of Animal Science, says, “We show that co-benefits for human and planetary health do not necessarily require wholesale changes to diets, such as adopting restrictive dietary patterns or excluding certain food groups altogether but can be achieved by making simple partial substitutions of red and processed meat, in particular, with plant protein foods.”

Plant-Based Health Benefits: A Gender Disparity

It is well recognized that diets heavy in animal products raise the risk of diabetes, heart disease, and some types of cancer. According to this study, a person may live an average of almost nine months longer if they substituted half of their diet’s red and processed meat with meals high in plant protein due to a lower risk of chronic illness.

When it comes to life expectancy, males stand to gain more from the changeover than females do, with the gain being double for males. On the other hand, there was a trade-off when substituting meals high in plant protein for dairy, such as an increase in calcium insufficiency of up to 14%, which resulted in lower benefits in life expectancy.

As senior author and an associate professor in the department of animal science at McGill University, as well as a scientist at the Research Institute of McGill University Health Centre, Sergio Burgos says, “I hope our findings will help consumers make healthier and more sustainable food choices and inform future food policy in Canada.”

The study’s conclusions provide direction as more people look for healthy, sustainable diets, enabling them to make decisions that are good for the environment and their own health.

The majority of Canadians’ diets would only need to be slightly altered to increase the intake of plant-based foods while reducing the consumption of red and processed meat, according to Patricia Eustachio Colombo, co-author and Honorary Research Fellow at the London School of Hygiene & Tropical Medicine’s Centre on Climate Change & Planetary Health.

Citation: Olivia Auclair, Patricia Eustachio Colombo, James Milner, and Sergio A. Burgos, “Partial substitutions of animal with plant protein foods in Canadian diets have synergies and trade-offs among nutrition, health, and climate outcomes,” Nature Food, February 16, 2024.