Effects of consuming an iron supplement with a meal containing animal or plant-based meat on indicators of iron status and anemia in women of reproductive age with iron deficiency: a randomized, controlled study.

BACKGROUND

Animal meat contains heme iron, which is more bioavailable and better absorbed than nonheme iron found in plants. Animal meat also contains a "meat factor" that stimulates absorption of nonheme iron.

OBJECTIVE

The objectives of this study were to determine whether consuming an iron supplement, a source of nonheme iron, with a meal containing animal meat once a day for 8 wk leads to improvements in iron status in females with iron deficiency compared with those consuming the same iron supplement with a meal containing plant-based meat.

METHODS

In a randomized, double-blinded, parallel-arm study, nonpregnant females of reproductive age (n = 52; 24 ± 7 y; body mass index 22.9 ± 3.0 kg/m2) with low iron stores (serum ferritin concentration <25 μg/L) were randomly assigned to consume an iron supplement containing 32 mg elemental iron (from ferrous sulfate) with a lunch meal containing either 4 oz. (113 g) of 1) beef (Animal) or 2) Beyond Meat (Plant) once a day for 8 wk. Meals were identical except for the addition of Animal or Plant. The primary outcomes were biochemical indicators of iron status and anemia. Data are presented as means ± standard deviation.

RESULTS

Baseline indicators of iron status and anemia did not differ between groups. Daily consumption of an iron supplement with a lunch meal for 8 wk improved serum ferritin concentrations (main time effect: +10.7 ± 9.6 μg/L, P < 0.0001), transferrin saturation (main time effect: +5.1% ± 18.7%, P = 0.048), soluble transferrin receptor (main time effect: -0.6 ± 1.0 mg/L, P < 0.001), body iron stores (main time effect: +2.8 ± 3.1 mg/kg, P < 0.0001), and hemoglobin (main time effect: +0.5 ± 0.9 g/dL, P = 0.0002) regardless of whether the meals contained Animal or Plant (treatment-by-time interaction: P > 0.05 for all indicators).

CONCLUSIONS

Findings suggest that the "meat factor" does not contribute substantially to improvements in iron status in women of reproductive age with iron deficiency when consumed with an iron supplement for 8 wk. This trial was registered at clinicaltrials.gov as NCT04793906.