A review published in BMJ Nutrition Prevention & Health found that drinking guava juice alongside iron supplements improved hemoglobin levels in teenage girls and pregnant women across 17 studies conducted in Indonesia. Participants who consumed guava juice with iron supplements saw an average hemoglobin increase of 1.71 g/dl, with pregnant women gaining 1.84 g/dl and teenage girls 1.52 g/dl.

Researchers analyzed 17 eligible studies published in English since 2000, including 15 quasi-experimental studies and two randomized controlled trials. Six of the studies focused on teenage girls and 11 on pregnant women. In five studies directly comparing groups of 102 participants each, those who took iron supplements with guava juice had hemoglobin levels 1.29 g/dl higher on average than those who took iron alone.

The researchers combined data from 12 of the studies involving 235 participants. They noted that guava contains up to four times more vitamin C per 100 grams than oranges, which may enhance iron absorption. Guava also provides vitamin A, folate, dietary fiber, and small amounts of iron.

"An increase of 1-2 g/dl may shift individuals from mild or moderate anemia to non-anemic categories, improving fatigue, cognitive function, and productivity outcomes," the researchers said. They added that integrating guava juice into school nutrition programs, antenatal care packages, or community health initiatives could represent a feasible approach to address mild-to-moderate anemia, aligning with the United Nations' Decade of Action on Nutrition (2016-2025), which emphasizes dietary diversification and locally sourced nutrient-rich foods.

"Given its nutritional richness, affordability, and cultural acceptance across Asia, guava juice offers a promising low-cost intervention. Strengthening local supply chains, standardizing formulations and embedding such dietary approaches within public health nutrition programs could collectively contribute to more sustainable anemia control," the researchers said.

Professor Sumantra Ray, chief scientist & executive director of the NNEdPro Global Institute for Food, Nutrition and Health, said, "This study builds on the established role of dietary sources high in vitamin C to enhance iron absorption and improve the effectiveness of iron supplementation." He also cautioned, "But quasi-experimental research, the wide variation in study design, small sample sizes, and limited length of follow-up mean that caution is required when interpreting the findings. Without further rigorous research, defining the best therapeutic dose and period of use, guava juice can't be recommended as an alternative to conventional treatment in those at risk of iron deficiency anemia."