I slip out of my rain jacket as I enter Maria Cordoba’s small apartment in Montreal’s Côte-des-Neiges neighborhood. The kettle whistles in her galley kitchen while she arranges a plate of homemade empanadas on her dining table. At 43, Maria works two jobs and raises her teenage son alone, leaving little time for cooking the traditional Colombian meals she grew up with.
“Most days I just grab something quick from the freezer section,” she tells me, gesturing toward her kitchen. “I know it’s not the best, but what choice do I have?”
What Maria doesn’t realize is that her reliance on ready-made meals might be affecting more than just her physical health. A groundbreaking study from McGill University has found a concerning link between ultra-processed foods and depression rates in Quebec, particularly among working parents and young adults.
The research, published last month in the Canadian Medical Association Journal, followed 4,300 Quebec residents over five years and discovered that those who consumed ultra-processed foods for more than 60% of their daily calories were 41% more likely to experience depression symptoms than those who ate less than 20%.
Dr. Elise Montpetit, the study’s lead author and a nutritional psychiatrist at McGill, explains the connection: “We’re seeing a clear relationship between what Quebecers eat and their mental health. The industrial processing of foods strips away nutrients while adding substances our bodies weren’t designed to handle in such quantities.”
When I visited Dr. Montpetit’s lab in early spring, her team was analyzing food samples for compounds they believe may disrupt the gut microbiome—the complex ecosystem of bacteria in our digestive system that increasingly appears connected to brain function and mood regulation.
“The gut-brain axis is revolutionary in how we understand mental health,” Dr. Montpetit says, holding up a petri dish. “What we’re finding is that excessive consumption of emulsifiers, artificial sweeteners, and certain preservatives may contribute to inflammation that affects neurotransmitter production.”
The findings are particularly troubling for Quebec, where ultra-processed food consumption has risen by 26% in the past decade according to Statistics Canada data. Nearly half of all calories consumed by Quebecers now come from foods that have been substantially altered from their original state through industrial processing.
Jean-Michel Trudeau, a 29-year-old software developer I met at a downtown Montreal café, represents the demographic most affected by these trends. “I’ve been on antidepressants for two years now,” he shares, stirring his coffee. “Never once did my doctor ask about my diet. I basically live on energy drinks and microwaveable meals.”
The correlation between diet and mental health isn’t entirely new. The Mental Health Commission of Canada has previously highlighted nutrition as an overlooked factor in mental health treatment. What’s novel about the McGill study is the specific connection to ultra-processed foods and its focus on Quebec’s unique food landscape.
Quebec has historically enjoyed a rich culinary tradition, but changing work patterns and family structures have eroded traditional mealtime practices. The province’s food security organization, Moisson Montréal, reports that food bank usage has increased 35% since 2019, with many clients citing lack of time and energy to prepare meals as factors in their food choices.
“We can’t talk about this issue without addressing the socioeconomic factors,” says community nutritionist Véronique Parent, who works with low-income families in Montreal’s east end. “Many of the parents I counsel understand that processed foods aren’t ideal, but they’re exhausted, working multiple jobs, and these products are designed to be convenient and affordable.”
Parent shows me a price
