Greater consumption of plant-based proteins — like those found in cereals and legumes — is associated with lower mortality risk, according to an observational study in JAMA Internal Medicine.

Roughly 70,000 people aged 40 to 69 in Japan completed food frequency questionnaires. Higher intake of plant protein was associated with lower mortality risk. A similar pattern was seen for cardiovascular mortality, but not cancer-related mortality. In contrast, increasing intake of total or animal-based protein was not associated with mortality.

Swapping out 3% of energy from animal protein with plant protein resulted in lower risk for total, cardiovascular, and cancer-related mortality. Risk reductions were even greater when substituting plants for processed meats.

The authors say that the lack of an association between animal protein and mortality might be because animal consumption is generally lower in Japan, and the main animal protein is fish. They conclude: "Our study suggests that encouraging diets with higher plant-based protein intake may contribute to long-term health and longevity."