Guava: Nutrients, What Research Shows and Safety

Guava is the fruit of the small tree Psidium guajava, in the myrtle family (Myrtaceae). The soft pink or white flesh, with its many small seeds, is eaten fresh, as juice or in drinks and sweets; the rind is often eaten too. People eat it for its taste, vitamin C and fiber. This page keeps the whole fruit apart from leaf teas, extracts and hype, and says what the research does and does not show.

Read this first

• Guava is an everyday food. The sources we read did not describe a guava-specific allergy, but any food can cause one. For trouble breathing or swelling of the face, lips or throat, call 911. See food allergy basics and emergency signs.
• Guava is very high in vitamin C: USDA lists about 228 mg per 100 g, more than twice the FDA Daily Value in 100 g. [1] This is a normal food amount; the NHS warnings about stomach upset refer to vitamin C supplements above 1,000 mg a day. [2]
• Guava also has natural sugar (about 15 g in one cup, USDA) and potassium. People with diabetes, kidney disease or on potassium-affecting medicines should ask their care team how fruit fits their diet. [1][3]
• Evidence summary: guava is a rich source of vitamin C and fiber. Trials in children suggest guava helps the body use iron from a meal. Claims for blood pressure, cholesterol and blood sugar come from small or old trials, and leaf-extract claims come mostly from the lab.

What is in it (USDA values)

Source: USDA FoodData Central, "Guavas, common, raw" (SR Legacy) [1]. Household portions in USDA: 1 cup (165 g); 1 fruit without refuse (55 g). % Daily Value uses the FDA 2016 Daily Values; values vary with variety, ripeness and storage.

USDA also lists lycopene (5,204 µg per 100 g) and beta-carotene (374 µg per 100 g), plant pigments. [1] USDA measures them but does not say what they do in the body; for lycopene and beta-carotene from this fruit we did not find human trials, so we make no health claim. Guava leaves contain other compounds (such as quercetin and gallic acid) studied for blood sugar, mostly in the lab and animals. [16]

What research says

Observational findings and a nutrient being present in a food are not proof that eating the food prevents or treats a disease. We did not find a regulator statement or a large modern trial supporting a disease claim for guava fruit: Proper evidence not found in the sources we read.

Eaten as food vs taken as a supplement or extract. The iron and gum trials used fresh fruit or juice. The diarrhoea and blood-sugar findings above used leaf decoctions or a lab-made fruit extract. Leaf teas, extracts and capsules are different products, and results for one form do not carry over to another. The extract paper also noted that storage and freeze-thawing seemed to weaken its effect. [11]

How much is a normal serving

• The USDA household portion in our data is 1 cup (165 g), or one fruit without refuse (55 g). [1] This is information, not a prescription.
• In the UK, the NHS counts 80 g of fresh, tinned or frozen fruit as one portion, 30 g of dried fruit as one portion, and fruit juice or smoothies as at most one portion a day (150 ml). [14]
• We did not find a source we read comparing fresh, frozen and canned guava for health outcomes. Juice has less fiber than the whole fruit; see fruit juice vs whole fruit and fresh, frozen and canned produce. Check labels of guava drinks and pastes for added sugar.

Safety, allergy and medicines

• Allergy. We did not find a source we could read describing guava allergy or a link between guava and latex-fruit allergy. That is a gap, not proof of safety. Stop eating and seek care if you get swelling, hives or breathing trouble; see when to seek medical help after a food reaction.
• Vitamin C amount. The NHS says taking more than 1,000 mg a day of vitamin C as supplements can cause stomach pain, diarrhoea and wind, which settle when stopping the supplements. [2] One cup of guava gives about 377 mg (USDA). [1] We did not find a source describing these effects from guava fruit itself.
• Potassium and kidneys. One cup gives about 15% of the Daily Value of potassium. [1] The NHS says older people may be more at risk of harm from potassium supplements because their kidneys may remove it less well. [3] People with kidney disease, or who take medicines that raise potassium, should ask a clinician or pharmacist about fruit; see foods and kidney disease: potassium and oxalates. We did not find a guava-specific medicine warning.
• Diabetes and sugar. Guava has about 15 g of sugar per cup (USDA). [1] The trials of guava and blood sugar are small, and one found fasting glucose rose when guava was eaten with the peel. [10] People on diabetes medicines should not use guava or guava leaf products to replace treatment; see foods for blood sugar control.
• Leaf teas and extracts. These are not covered by food-safety knowledge about the fruit. The leaf trials we read reported no adverse events, but they were small and short. [12] We did not find long-term safety data.
• Pregnancy. We did not find a guava-specific statement; see foods in pregnancy: what official bodies advise.
• Seeds. We did not find a source on guava seeds and choking or bowel problems, so we make no claim.

Choosing, storing and food safety

• Wash fresh guavas under running water before cutting, even if you will peel them. Do not use soap, detergent or commercial produce wash. [15]
• Cut away damaged or bruised areas and throw away produce that looks rotten. [15]
• Use clean boards and knives, and keep fresh produce apart from raw meat. [15] See food storage, leftovers and food safety basics.

Related pages

• Fruit juice vs whole fruit
• Fresh, frozen and canned produce
• Citrus fruits
• Foods, kidney disease, potassium and oxalates
• Foods and medicine interactions
• Foods for blood sugar control