The Study
Enhancement of iron, zinc, and calcium bioaccessibility and bioavailability in green gram (Vigna radiata L.) supplemented with buttermilk through phytate reduction: an in vitro dietary evaluation
This study tested what happens to minerals in green gram and buttermilk inside a test tube and a lab-grown cell line — not in a real person’s body. So we can only say it might work that way in humans, but we don’t know for sure.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Green gram (a type of bean) has lots of iron and calcium, but a compound called phytic acid blocks your body from absorbing them. Buttermilk has natural enzymes that break down this blocker.
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 57 / 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.
- 1Yes — this means eating beans with buttermilk could help prevent iron and calcium deficiency, especially in plant-based diets.
- 2Buttermilk cut phytic acid in beans by 40%, boosted iron absorption by 210%, calcium by 133%, and zinc by 23% in lab tests.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Nutrition
Year
2026
Authors
B. Varshanath, Delvin T. Robin, S. Meera, Anusree Dileep, S. Archana, N. Chandran, M. Vandana Rani
Related Content
Claims (6)
In laboratory tests, green gram has high levels of phytate relative to iron, calcium, and zinc, which can block mineral absorption; treating it with buttermilk lowers these phytate-mineral ratios to levels that do not inhibit absorption.
Buttermilk contains an enzyme that breaks down phytic acid in green gram during digestion, resulting in higher availability of minerals.
Cooking green gram reduces phytic acid by 12%, and adding buttermilk while cooking reduces it by another 40% compared to cooking without buttermilk.
When buttermilk was added to cooked green gram in a laboratory setting, the phytic acid content dropped by 40%, from 1.20 grams per 100 grams to 0.54 grams per 100 grams.
When buttermilk is added to cooked green gram in a laboratory digestion model, iron, calcium, and zinc become more accessible and more available for absorption compared to cooked green gram alone, due to chemical changes from organic acids and enzymes in buttermilk.
Lectins, phytates, and oxalates in plant foods reduce the absorption of minerals and cause irritation of the gut lining.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.