An inexpensive tropical fruit may help tackle one of the world's most common nutritional deficiencies, with researchers finding that guava juice can significantly improve hemoglobin levels in women and girls.
Study: Effect of guava juice intake on haemoglobin levels in Indonesian females: a systematic review and meta-analysis. Image credit: New Africa/Shutterstock.com
A systematic review from Indonesia, published in the journal BMJ Nutrition, Prevention & Health, indicates that adding guava juice to the diet could boost hemoglobin levels in adolescent girls and pregnant women. This could potentially offer a low-cost dietary complement to iron supplementation, given the high prevalence of iron-deficiency anemia among females, especially in low- and middle-income countries (LMICs).
Iron deficiency anemia among young women
In 2021, anemia was estimated to affect about 45 % of pregnant women and 39.5 % of non-pregnant women worldwide. Indonesia had similar figures: 48.9 % among pregnant women and 32 % among adolescent girls. Women with severe anemia are twice as likely to die during pregnancy and postpartum, compared to those with mild anemia.
Iron deficiency is the primary cause of anemia, especially in LMICs. The reasons include poor dietary intake, high prevalence of infection, heavy bleeding during periods, frequent pregnancies, and low healthcare access.
Iron deficiency anemia is conventionally treated with iron supplementation, but oral iron can cause symptoms such as diarrhea or constipation, other gut symptoms, an unpleasant taste, and may be inaccessible to some women. Pregnancy can further complicate treatment, as physiological changes may decrease iron absorption during this period.
This has resulted in persistently low use of iron supplements, even with national nutritional programs like the Gerakan Nasional Aksi Bergizi or iron supplementation programs targeting pregnant women and adolescent girls.
Nutritional benefits of guava
Guava is a locally cultivated and inexpensive fruit. Its juice is rich in vitamin C, folate, antioxidants, flavonoids, and polyphenols, and other micronutrients. The current study aimed to examine the potential of guava juice as a natural adjunct to iron therapy.
Guava juice and iron supplements
This systematic review and meta-analysis included 17 Indonesian studies published between 2019 and 2024, with a total of 726 participants. Most studies were quasi-experimental, while two were randomized controlled trials (RCTs). The participants were pregnant women or adolescent girls, with numbers ranging from 15 to 230.
While the findings were encouraging, most of the evidence came from relatively small quasi-experimental studies rather than randomized trials.
Most studies evaluated guava juice alongside iron supplementation, while a few used it alone or in combination with carrot or red spinach juice. Intervention periods ranged from five days to three months.
Eight studies compared guava juice plus iron supplementation with iron supplementation alone, although only five of these provided extractable data for the direct comparative meta-analysis. One study used papaya juice and another dragon fruit juice as comparators. The remaining seven studies had no control group.
The meta-analysis was limited to 12 studies because the others lacked usable data. The results were promising, consistently indicating a significant average increase of 1.7 g/dL in hemoglobin among pooled participants who consumed guava juice.
When stratified by participant type, adolescents had a mean improvement in hemoglobin levels of 1.5 g/dL, versus 1.8 g/dL among pregnant women.
Across five studies that directly compared guava juice interventions with iron-only controls, hemoglobin levels increased by an additional 1.3 g/dL on average in the guava juice groups. This was confirmed to be robust by sensitivity analyses, with little evidence of publication bias.
Possible physiological pathways
The degree of improvement in hemoglobin observed by the researchers is substantial enough to potentially move some individuals with mild or moderate anemia into non-anemic categories. Other experimental studies involving male athletes, anemic schoolchildren, and postpartum women have shown similar positive effects from both guava juice and guava fruit consumption.
This suggests the beneficial impact of guava’s high vitamin C and polyphenol content, irrespective of the form of consumption. Vitamin C improves the absorption of iron from non-heme sources, including iron supplements, by converting ferric iron into its more absorbable ferrous form.
Guava also contains folate, antioxidants, flavonoids, and polyphenols that may support red blood cell survival by reducing oxidative stress. The researchers suggest that juice preparation may improve compliance and could enhance nutrient availability, while promoting more consistent intake.
Study limitations
Despite the promising results, the review also noted limitations. All studies were conducted in Indonesia, limiting generalizability to other populations. Many studies had a moderate risk of bias, sample sizes were relatively small, and most were non-randomized designs. Missing data also reduced the size of the meta-analysis. The studies showed high heterogeneity due to differences in guava dosage, preparation, and duration.
Future follow-up research should include larger, well-designed RCTs across multiple countries with standardized reporting, including regimens and outcomes. These should include not only hemoglobin but also parameters such as transferrin and ferritin that reflect broader health impacts and long-term effectiveness. This would help identify the optimal dosage, dosing frequency, and duration of use.
Implementation research is also required to understand how far such an intervention could be embedded into existing programs, supporting its real-world relevance.
Conclusion
Overall, the study concludes that guava juice significantly improves hemoglobin levels in women and adolescent girls. The authors highlight the potential of guava juice as an affordable, culturally acceptable, and locally available dietary adjunct to iron supplementation and anemia prevention programs in resource-limited settings.
It is particularly relevant in tropical countries with high guava production, such as India and Indonesia. The authors suggest integrating guava juice into school nutrition programs, antenatal care packages, and community health initiatives.
This could be a sustainable, complementary strategy to prevent and treat mild-to-moderate anemia, aligning with the United Nations’ Decade of Action on Nutrition (2016–2025) and its dietary emphasis on local foods.
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