Biofortified Yellow-Fleshed Potatoes Provide More Absorbable Zinc than a Commonly Consumed Variety: A Randomized Trial Using Stable Isotopes in Women in the Peruvian Highlands.

BACKGROUND: Zinc-biofortified potatoes have considerable potential to reduce zinc deficiency because of their low levels of phytate, an inhibitor of zinc absorption, and their high consumption, especially in the Andean region of Peru. OBJECTIVES: The purpose of this study was to measure fractional and total zinc absorption from a test meal of biofortified compared with regular potatoes. METHODS: We undertook a single-blinded randomized crossover study (using 67Zn and 70Zn stable isotopes) in which 37 women consumed 500-g biofortified or regular potatoes twice a day. Urine samples were collected to determine fractional and total zinc absorption. RESULTS: The zinc content of the biofortified potato and regular potato was 0.48 (standard deviation [SD]: 0.02) and 0.32 (SD: 0.03) mg/100 g fresh weight, respectively. Mean fractional zinc absorption (FZA) from the biofortified potatoes was lower than from the regular potatoes, 20.8% (SD: 5.4%) and 25.5% (SD: 7.0%), respectively (P < 0.01). However, total zinc absorbed was significantly higher (0.49; SD: 0.13 and 0.40; SD: 0.11 mg/500 g, P < 0.01, respectively). CONCLUSIONS: The results of this study demonstrate that biofortified potatoes provide more absorbable zinc than regular potatoes. Zinc-biofortified potatoes could contribute toward reducing zinc deficiency in populations where potatoes are a staple food. This trial was registered at clinicaltrials.gov as NCT05154500.

Total Iron Absorbed from Iron-Biofortified Potatoes Is Higher than that from Nonbiofortified Potatoes: A Randomized Trial Using Stable Iron Isotopes in Women from the Peruvian Highlands.

BACKGROUND: Yellow-fleshed potatoes biofortified with iron have been developed through conventional breeding, but the bioavailability of iron is unknown. OBJECTIVES: Our objective was to measure iron absorption from an iron-biofortified yellow-fleshed potato clone in comparison with a nonbiofortified yellow-fleshed potato variety. METHODS: We conducted a single-blinded, randomized, crossover, multiple-meal intervention study. Women (n = 28; mean ± SD plasma ferritin 21.3 ± 3.3 µg/L) consumed 10 meals (460 g) of both potatoes, each meal extrinsically labeled with either 58Fe sulfate (biofortified) or 57Fe sulfate (nonfortified), on consecutive days. Iron absorption was estimated from iron isotopic composition in erythrocytes 14 d after administration of the final meal. RESULTS: Mean ± SD iron, phytic acid, and ascorbic acid concentrations in iron-biofortified and the nonfortified potato meals (mg/per 100 mg) were 0.63 ± 0.01 and 0.31 ± 0.01, 39.34 ± 3.04 and 3.10 ± 1.72, and 7.65 ± 0.34 and 3.74 ± 0.39, respectively (P < 0.01), whereas chlorogenic acid concentrations were 15.14 ± 1.72 and 22.52 ± 3.98, respectively (P < 0.05). Geometric mean (95% CI) fractional iron absorption from the iron-biofortified clone and the nonbiofortified variety were 12.1% (10.3%-14.2%) and 16.6% (14.0%-19.6%), respectively (P < 0.001). Total iron absorption from the iron-biofortified clone and the nonbiofortified variety were 0.35 mg (0.30-0.41 mg) and 0.24 mg (0.20-0.28 mg) per 460 g meal, respectively (P < 0.001). CONCLUSIONS: TIA from iron-biofortified potato meals was 45.8% higher than that from nonbiofortified potato meals, suggesting that iron biofortification of potatoes through conventional breeding is a promising approach to improve iron intake in iron-deficient women. The study was registered at www. CLINICALTRIALS: gov as Identifier number NCT05154500.