Red meat or plant-based mince? In a 10-week trial, heart markers didn't budge either way

Whether to eat red meat or switch to plant-based alternatives is often argued, rarely tested head to head. A randomised dietary trial published in The American Journal of Clinical Nutrition on 1 October 2026, from the University of Auckland, gave healthy adults one of two healthy eating patterns for 10 weeks at home: a flexitarian diet with moderate amounts of pasture-raised red meat (3.3 serves a week by week 10) or a vegetarian diet with plant-based meat alternatives.

Seventy-eight people completed the study. The researchers looked mainly at blood fatty acids. One omega-3 fat, docosapentaenoic acid (DPA), fell in the vegetarian group during the first five weeks compared with the flexitarian group, then recovered between weeks 5 and 10. There were no differences between the diets in cardiometabolic markers. Of 259 blood fat species measured, only one differed after correcting for multiple tests.

The authors conclude that moderate pasture-raised red meat within a healthy diet did not harm cardiometabolic markers and kept DPA steady. Ten weeks is short, the participants were healthy, and blood markers are not the same as heart attacks or cancer, so this does not settle the long-term question. It does suggest that, over a few weeks, the overall quality of the diet matters more than which of these two protein sources is on the plate.