The Claim

Soya milk has a higher digestible indispensable amino acid score (DIAAS) than tofu when consumed by adults, due to greater digestibility of sulphur-containing amino acids in soya milk compared to tofu, with measured DIAAS values of 117% and 97%, respectively.

Source: True ileal amino acid digestibility and digestible indispensable amino acid scores (DIAASs) of plant-based protein foods.

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
18score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Quantitative
1 study reviewed
In plain English

Soya milk provides more usable essential amino acids than tofu, even though both are made from the same soy source, because the body absorbs sulphur-containing amino acids more efficiently from soya milk than from tofu.

See the scientific wording

Soya milk has a higher digestible indispensable amino acid score (DIAAS) than tofu despite identical protein sources, due to lower digestibility of sulphur-containing amino acids in tofu, with DIAAS values of 117% and 97% respectively in adults.

Why this might work

When soy is turned into tofu, the proteins clump together in a way that traps sulphur-containing amino acids inside tight structures. These trapped amino acids cannot be reached by digestive enzymes, so they pass through the small intestine undigested. The body responds by releasing more mucus and other substances into the intestine, which further reduces the amount of these amino acids that can be absorbed. As a result, tofu provides fewer usable sulphur-containing amino acids than soya milk, even though both come from the same soybeans.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: True ileal amino acid digestibility and digestible indispensable amino acid scores (DIAASs) of plant-based protein foods.

    Even though soya milk and tofu come from the same soybeans, the way tofu is made makes it harder for your body to use certain important amino acids, so soya milk gives you more usable protein.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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