Protein is essential for maintaining muscle throughout life.
As we age, preserving muscle becomes increasingly important for strength, mobility and independence.
Animal foods are often considered the most obvious sources of protein. But plant foods can also make an important contribution to muscle health.
Plant protein can support muscle
Plant protein comes from many different foods.
Soy foods, beans, lentils, peas, nuts, seeds and whole grains all contribute protein to the diet.
Research comparing plant and animal protein shows that plant protein can support muscle mass.
Importantly, in randomized trials involving adults aged 60 and older, researchers found no significant difference in muscle mass between plant and animal protein.
This does not mean that every protein source has exactly the same nutritional properties.
It means that a healthy diet does not have to depend primarily on animal protein to support muscle.
Protein quality matters
Proteins are made from amino acids.
Some amino acids are called essential amino acids because the body cannot make them and must obtain them from food.
Different protein sources contain different amounts and proportions of these amino acids. They can also differ in how well their protein is digested.
Soy is one of the most extensively studied plant proteins. In randomized trials, soy protein produced similar results to milk protein for muscle mass.
Evidence for other individual plant proteins is still more limited.
Think about the whole diet
For someone eating more plant-based foods, the practical goal is not to find one plant food that replaces every animal protein.
Instead, include different protein-rich foods across the day.
Beans and lentils can be combined with whole grains. Soy foods such as tofu, tempeh and edamame provide substantial amounts of protein. Nuts and seeds can contribute additional protein alongside other nutrients.
A varied diet makes it easier to obtain the range of essential amino acids the body needs.
And protein should not be considered in isolation.
Regular resistance exercise provides an important stimulus for maintaining muscle. Protein supplies the nutritional building blocks needed to support that process.
