Anemia (iron defficient) is still a problem for millions of people around the globe. It’s particularly common in girls and women, causing fatigue, brain fog, and a number of other symptoms. The usual response is iron supplementation. But iron pills can be hard to tolerate, hard to access, and hard to stick with.

So, researchers asked a surprisingly simple question: could a glass of guava juice help?

It sounds silly, but the answer is surprisingly promising. After pooling data from 17 different studies the authors found that guava juice consumption was associated with a significant rise in hemoglobin, the protein in red blood cells that carries oxygen through the body.

The study focused on Indonesia, where anemia is particularly common: 48.9% among pregnant women and 32% among adolescent girls. That makes Indonesian females a high-priority population for testing practical anemia interventions.

They used guava because the fruit is rich in vitamin C. It has up to four times more vitamin C than oranges. This helps the body absorb non-heme iron, the form of iron found in plant foods and many supplements. Basically, vitamin C changes iron into a form that the intestine can take up more easily. Guava also contains vitamin A, folate, and small amounts of iron.

Researchers looked at 17 studies which collectively enrolled 726 female participants. The studies varied widely. Some used red guava juice; one used crystal guava juice. Some gave juice alone, while others combined it with iron tablets. Doses ranged from preparations made with 100 grams of guava to 300 milliliters of juice per day, and interventions lasted from five days to three months.

That variety makes the results harder to interpret. If hemoglobin rises, was it because of the guava, the iron tablets, the duration of the intervention, or other dietary changes not fully tracked?

The authors tried to address this by looking separately at studies that compared guava plus iron with iron alone. In that comparison, guava still appeared to add something. Across five studies, participants receiving guava juice plus iron had hemoglobin levels 1.29 grams per deciliter higher than those receiving iron alone.

This value is enough to get a lot of people out of the anemia range, the researchers say.

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,” suggest the researchers.

For someone worried about iron deficiency, the guava study offers an encouraging idea that could help. No one is saying you should drop the idea of pills. In fact, quite the opposite: guava juice can help complement pills.

Anemia programs often focus on distribution: get iron tablets into schools, clinics, and antenatal care programs. But distribution is only half the battle. People have to take the tablets and their bodies have to absorb the iron. The intervention has to fit daily life.

Guava juice checks several of those boxes. It’s widely grown and consumed across tropical and subtropical Asia, but guava juice is also common and relatively affordable in many supermarkets in Western countries.

Ultimately, guava juice shouldn’t be seen as a substitute for diagnosis or treatment. If iron deficiency is suspected, the practical first step is a blood test, often including hemoglobin and ferritin. This is especially important for women with heavy periods, pregnancy, recent childbirth, gastrointestinal symptoms, vegan or vegetarian diets, endurance training, or a history of bleeding.

Iron deficiency can creep up quietly, often beginning with unusual tiredness, weakness, dizziness, headaches or trouble concentrating. As it worsens into iron deficiency anemia, people may feel short of breath, notice a racing heartbeat, look paler than usual or feel unusually cold, especially in the hands and feet. Some develop brittle nails, hair shedding, restless legs or cravings for non-food substances such as ice, clay or dirt, a symptom known as pica. Because these signs can have many causes, symptoms alone cannot confirm iron deficiency; blood tests are needed to check hemoglobin and iron stores.

The World Health Organization notes that anemia can affect school performance, productivity and quality of life, and in pregnancy it is linked to poor maternal and birth outcomes.

Journal Reference: Mansoor et al. Effect of guava juice intake on haemoglobin levels in Indonesian females: a systematic review and meta-analysis. BMJ Nutrition, Prevention, 2026; e001466 DOI: 10.1136/bmjnph-2025-001466