The Study
Thermal-induced interactions between soy protein isolate and malondialdehyde: Effects on protein digestibility, structure, and formation of advanced lipoxidation end products.
This study looked at what happens when soy protein and a chemical from burnt fats are heated in a test tube. It found that they change and form new substances, but it didn't test this in people or animals — so we can't say it affects our health.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
When soy protein is heated with a chemical from burnt fats, it changes shape and becomes harder for the body to break down.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 53 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This suggests that high-heat cooking of soy-based foods with fatty ingredients might reduce their nutritional value by making protein harder to digest.
- 2Heating soy protein with malondialdehyde at 100–180°C for up to 60 minutes reduced digestibility and created 9 types of harmful chemical byproducts (7 non-crosslinked, 2 crosslinked).
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Food research international
Year
2024
Authors
Yazhou Ji, Ruican Wang, Yuanyifei Wang, Dongfei Tan, Yaya Wang, Yuekun Wu, Haoxin Cui, Yan Zhang, Shuo Wang
Related Content
Claims (4)
Tofu contains all essential amino acids in better proportions than most plant proteins, but the body absorbs fewer of those amino acids from tofu than from eggs, meat, or dairy.
When soy protein isolate is heated, higher levels of malondialdehyde lead to the formation of advanced lipoxidation end products, including both non-crosslinked and crosslinked types.
When soy protein is heated, chemical byproducts from acrolein react with the protein to form rigid crosslinks that cause protein units to clump together.
Heating soy protein with malondialdehyde between 100°C and 180°C for up to 60 minutes decreases its digestibility and causes chemical changes in the protein structure, including oxidation and aggregation, which coincide with the formation of advanced lipoxidation end products.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.