Meat diets vs. vegetarianism

[Laird]

A dietary swap that could lengthen your life? Study finds replacing butter with plant-based oils cuts premature death risk by 17 percent by Ryan Jaslow for Mass General Brigham Communications on March 6, 2025.

The researchers examined diet and health data from 200,000 people followed for more than 30 years and found that higher consumption of plant-based oils — especially soybean, canola, and olive oil — was associated with lower total, cancer, and cardiovascular disease mortality, whereas butter use was linked with increased risk of total and cancer mortality. The results are published in JAMA Internal Medicine.

Using statistics to compare death rates across different diet intake levels, the researchers found that participants who ate the most butter had a 15 percent higher risk of dying than those who ate the least. In contrast, those who ate the most plant-based oils had a 16 percent lower risk of death than those who ate the least.

The researchers also did a substitution analysis, which mimics how swapping butter for plant oils would impact health in a feeding trial. They found that substituting 10 grams of butter a day (less than a tablespoon) with equivalent calories of plant-based oils could lower cancer deaths and overall mortality by 17 percent.