Mush: cornmeal porridge, studied mostly as a carrier

The one systematic review that touches mush is a Cochrane review, and on this question it rests on a single study of 38 pregnant women. Those given folic acid fortified maize porridge had higher red cell folate (mean difference 238.9 nmol/L, 95% CI 149.4 to 328.4), with the certainty rated very low. The porridge was fortified for the purpose. Most research on mush treats it as a vehicle for something else. In a randomized crossover study of 55 Kenyan infants aged 8 to 12 months, adding 3 g of galacto-oligosaccharides to iron-fortified maize porridge raised iron absorption from 12.5 to 22.2 percent in single test meals. In a 16-week randomized trial of 279 Kenyan children aged 12 to 59 months, a maize and amaranth porridge carrying 23 mg of iron a meal did not improve iron status. The authors put that down to phytate, a reason they inferred without measuring absorption. Navajo blue corn mush made with juniper ash has 96 mg of calcium and 2.9 mg of iron per 3.5 oz (100 g) at 54 calories, by a single USDA record. The calcium comes from the ash, so it depends on how much ash is stirred in.

The numbers, per 3.5 oz (100 g)

How much is actually in it

• Navajo blue corn mush made with juniper ash carries 96 mg calcium and 2.9 mg iron per 3.5 oz (100 g) at only 54 calories, by a single USDA record. — USDA SR Legacy record for Mush, blue corn with ash (Navajo) (n = 1 record) Evidence E source
  Per 100 g: calcium 96 mg, iron 2.92 mg, zinc 0.76 mg, energy 54 calories, water 86.67 g

What a real portion looks like

• A cup of cooked cornmeal mush weighs about 8.5 oz (240 g), and one ounce of dry cornmeal swells to about 6.7 oz (190 g) of mush. — USDA FNDDS portion weights for cornmeal mush, no added fat Evidence E source
  1 cup cooked 240 g; 1 oz dry yields 190 g; 1 strip or slice 50 g; 1 cup dry yields 955 g

What your body absorbs

• In a 16-week randomized trial of 279 Kenyan preschool children, maize porridge with added amaranth raised iron to 23 mg a meal without improving iron status, while low-dose NaFeEDTA powder cut anemia by 46%. — 279 Kenyan children aged 12-59 months, 16 weeks (n = 279) Evidence B source
  Micronutrient powder: anemia -46% (95% CI -67 to -12), iron deficiency -70% (-89 to -16); amaranth porridge: no significant change in Hb or iron status
• In a randomized crossover study of 55 Kenyan infants, adding 3 g of galacto-oligosaccharides to iron-fortified maize porridge raised iron absorption from 12.5% to 22.2%. — 55 partially breastfed Kenyan infants aged 8-12 months, single test meals (n = 55) Evidence B source
  Fractional iron absorption median 22.2% (IQR 16.5-25.9) with GOS vs 12.5% (9.5-20.9) without, P = 0.005; HMO no effect (13.3%)

What cooking and storage change

• In a randomized study of 40 adults in Soweto, nixtamalization (alkaline cooking) of moldy maize cut fumonisin B1 by 95%, leaving urinary exposure no different from clean maize. — 40 healthy adult volunteers, Kliptown, Soweto, South Africa (n = 40) Evidence B source
  Fumonisin B1 and B2 -95%, zearalenone -89% in maize; urinary FB1 and ZEN not different between groups (p > 0.05)
• In 5 women, calcium absorption from tortillas made with low-phytate maize was 50% against 35% from ordinary maize, because nixtamalization adds calcium but only modestly removes phytate. — 5 healthy adult women, two test meals of about 140 g tortillas one month apart (n = 5) Evidence C source
  Fractional calcium absorption 0.50 +/- 0.03 (low-phytate) vs 0.35 +/- 0.07 (control), P = 0.003

What it does to your health

• A Cochrane review found pregnant women given folic acid fortified maize porridge had higher red cell folate (MD 238.9 nmol/L), but from one study of 38 women with very low certainty. — Pregnant women receiving folic acid-fortified maize porridge vs no intervention (n = 38) Evidence B source
  Erythrocyte folate MD 238.90 nmol/L (95% CI 149.40 to 328.40); very low-certainty evidence

Safety, limits and interactions

• In a randomized study of 33 Ugandan children under 5 with malaria, lumefantrine taken with oil-fortified maize porridge was absorbed as well as with milk (AUC 6.26 vs 6.01 hr*ug/mL). — Ugandan children under 5 with uncomplicated falciparum malaria, 6-dose artemether-lumefantrine (n = 33) Evidence B source
  AUC0-8 hr geometric mean 6.26 (95% CI 4.5-8.43) with porridge plus oil vs 6.01 (3.26-11.1) with milk, p = 0.9

The bottom line

A cup of cooked cornmeal mush weighs about 8.5 oz (240 g), and one ounce of dry cornmeal swells to about 190 g. Cooking maize with alkali changes two things. In a randomized study of 40 adults in Soweto, nixtamalization, cooking with lime, cut fumonisin B1 in visibly moldy maize by 95 percent, and urinary exposure afterward was no different from clean maize. Juniper ash is a related alkaline method, and we found no test of it. The second change is calcium. In 5 women, tortillas made from low-phytate maize gave 50 percent calcium absorption against 35 percent from ordinary maize, because nixtamalization adds calcium while removing only a little of the phytate. Five people in a non-randomized comparison is a hint, and it was measured on tortillas. Who should be careful. The mold finding above shows that lime cooking lowered toxins in one small study. It does not show that moldy maize is safe to eat, and plain or ash-cooked mush was not tested. The one medicine study is narrow: in 33 Ugandan children under 5 with malaria, the drug lumefantrine was absorbed as well with oil-fortified maize porridge as with milk (AUC 6.26 against 6.01 hr*ug/mL, p = 0.9). Plain mush without the oil was not tested. We found no data on mush in allergy or with other medicines, and no study of how much of the ash calcium the body takes up.

Sources

1. mshc-r2-01 · USDA FoodData Central SR Legacy, dataset
   Mush, blue corn with ash (Navajo) (FDC 167627, SR Legacy, American Indian/Alaska Native Foods): energy 54 kcal, calcium 96 mg, iron 2.92 mg, zinc 0.76 mg, water 86.67 g per 100 g; Foundation samples 0, CoFID match none
   USDA FoodData Central, SR Legacy, FDC 167627 · checked 2026-09-29
2. mshc-r2-02 · USDA FNDDS portion weights, dataset
   Cornmeal mush, no added fat (FNDDS 56201516, fdc 2708374): 1 cup, cooked = 240 g; 1 oz, dry, yields = 190 g; 1 strip or slice = 50 g; 1 cup, dry, yields = 955 g
   USDA FNDDS 2021-2023, food code 56201516 · checked 2026-09-29
3. mshc-r2-03 · RCT
   children (n = 279; 12-59 mo) were randomly assigned to: unrefined maize porridge (control; 4.1 mg of iron/meal; phytate:iron molar ratio 5:1); unrefined maize (30%) and amaranth grain (70%) porridge (amaranth group; 23 mg of iron/meal; phytate:iron molar ratio 3:1) ... Consumption of MNP reduced the prevalence of anemia [-46% (95% CI: -67, -12)], iron deficiency [-70% (95% CI: -89, -16)], and IDA [-75% (95% CI: -92, -20)]. ... There was no significant change in Hb or iron status in the amaranth group.
   J Nutr, 2012 · checked 2026-09-29
4. mshc-r2-04 · RCT, crossover
   In a randomized, prospective crossover study, 55 infants (aged 8-12 mo) were fed test meals fortified with 1 of the following ... FIA from the FeFum+GOS group [median (IQR) 22.2% (16.5%-25.9%)] was higher than that from the FeFum group [12.5% (9.5%-20.9%)] (P = 0.005).
   Am J Clin Nutr, 2023 · checked 2026-09-29
5. mshc-r2-05 · RCT
   Forty adult healthy volunteers from an informal settlement in Kliptown, Soweto (South Africa), were randomly assigned to consume control maize or visibly moldy maize subjected to nixtamalization. Nixtamalization achieved a reduction in fumonisin B3 and deoxynivalenol (DON) to unquantifiable or undetectable levels in maize, while reducing fumonisin B1 (FB1), fumonisin B2, and zearalenone (ZEN) by 95%, 95%, and 89%, respectively.
   Toxins (Basel), 2025 · checked 2026-09-29
6. mshc-r2-06 · clinical trial, non-randomized
   Calcium fortification of maize has been achieved for millennia in Central America by the process of nixtamalization. Bioavailability of calcium is, however, compromised by phytate, which is present in large quantities in maize kernels and is only modestly reduced by nixtamalization. ... Mean fractional absorption of calcium from tortillas prepared from the low-phytate maize (0.50 +/- 0.03) was significantly (P = 0.003) greater than that from tortillas prepared from the control maize (0.35 +/- 0.07).
   Am J Clin Nutr, 2005 · checked 2026-09-29
7. mshc-r2-08 · Cochrane systematic review
   pregnant women who received folic acid-fortified maize porridge had significantly higher erythrocyte folate concentrations (mean difference (MD) 238.90 nmol/L, 95% CI 149.40 to 328.40); 1 study, 38 participants; very low-certainty evidence)
   Cochrane Database Syst Rev, 2019 · checked 2026-09-29
8. mshc-r2-07 · RCT
   Evaluable children (n = 33) included 16 in arm A and 17 in arm B. The AUC0-8 hr was comparable between A and B [geometric mean (95% CI): 6.01 (3.26-11.1) versus 6.26 (4.5-8.43) hr*μg/mL, p = 0.9].
   Basic Clin Pharmacol Toxicol, 2017 · checked 2026-09-29