Even though healthy adult men eating legumes instead of meat consume much more plant-based iron, their blood iron levels don’t drop—likely because other foods in their diet help their bodies absorb it better.
Evidence from Studies
No evidence studies found yet.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Whether replacing red meat with legumes consistently maintains iron status across diverse populations, accounting for dietary enhancers (vitamin C) and inhibitors (phytates) in plant-based diets.
A systematic review and meta-analysis of 20+ RCTs measuring ferritin, hemoglobin, and transferrin receptor before and after replacing ≥20% animal protein with legumes, stratifying by vitamin C intake, phytate levels, and baseline iron status.
Whether replacing red meat with legumes for 12 months maintains iron status in men with borderline iron stores.
A double-blind RCT of 200 healthy men aged 25–50 with baseline ferritin 20–40 µg/L, randomized to legume-based or meat-based diets for 12 months, with monthly ferritin, hemoglobin, and dietary vitamin C intake monitoring, and iron absorption tests using stable isotopes.
Whether individuals who replace red meat with legumes over 5–10 years have higher rates of iron deficiency anemia compared to meat consumers.
A prospective cohort study following 12,000 adults for 10 years, collecting dietary data and annual hemoglobin and ferritin measurements, comparing those who replace ≥20% red meat with legumes versus those who do not, with iron deficiency anemia as the primary outcome.
Whether populations with high legume and low meat intake have lower average ferritin levels at a single point in time.
A national survey measuring serum ferritin and dietary intake in 5,000 adult men, comparing those consuming ≥150g/day legumes and ≤100g/week red meat to those consuming ≥300g/week red meat and <50g/day legumes.
Whether an individual develops low ferritin after switching from meat to legumes.
A case series of 10 men with baseline ferritin 30–50 µg/L who switched to a legume-based diet for 6 months, with pre- and post-intervention ferritin measurements.