Not All Plant-Based Foods Protect Your Heart—Here's Why Processing Matters

A new study has found that not all plant cell-based foods are equally good for heart health. Researchers tracked the diets of over 60,000 French adults for more than nine years. The findings show that heavily processed indoor plants may not lower cardiovascular risk—even if they seem healthy at first glance.

The study, published in The Lancet Regional Health – Europe, analysed data from 63,835 adults in the NutriNet-Santé cohort. Participants were monitored for an average of 9.1 years, with researchers assessing both the nutritional quality and processing level of their diets.

Those who ate mostly low-quality, ultra-processed plant foods—such as refined bread, cereals, and veggie burgers—faced a 40% higher risk of cardiovascular disease. In contrast, people who chose high-quality, minimally processed plants saw their risk drop by about 40%.

The research also compared these foods to animal products. While some ultra-processed plant options (like meat alternatives) did not raise the risk of cancer, heart disease, or diabetes, they did not reduce it either. Whole grains, however, were linked to lower type-2 diabetes risk and overall mortality in separate analyses of nearly 200,000 and over 300,000 U.S. participants.

Scientists stressed that the study does not dismiss plant-based eating. Instead, it highlights the need to focus on whole, nutrient-dense plants rather than relying on processed substitutes.

The findings suggest that simply choosing plant-based foods is not enough to protect heart health. The level of processing and overall nutritional quality play key roles in determining cardiovascular risk. Researchers recommend prioritising minimally processed plants for the greatest benefit.