What the evidence says. Early or small human trials; promising but not yet conclusive.
Nutrition per serving 1 medium (85 g)
Water79 g93%
Sugars4 g5%
Other carbs0.8 g1%
Protein0.5 g1%
Fat0.3 g0%
What's in one serving, by weight — average composition (USDA).One serving as % of the adult daily requirement (FDA Daily Values). The bold outer ring = 100% of a day's needs.
Wax Apple (Syzygium samarangense) is a fruit used for hydration with a very low calorie load (high water content, ~25 kcal/100 g). NutriDex grades the human evidence as Preliminary. Wax apple (Syzygium samarangense), also called java/rose apple or jambu air, is a very watery, low-calorie tropical fruit (~25 kcal/100 g) valued more as a refreshing, hydrating snack than as a dense nutrient source. Laboratory and rodent studies show its leaf and fruit polyphenols (flavonols such as myricetin/myricitrin, C-methylated chalcones, and condensed/ellagitannins) have antioxidant, antihyperglycemic, anti-inflammatory and cytotoxic activities, including protection of pancreatic beta-cells in streptozotocin-diabetic rats and chalcones cytotoxic to colon cancer cells in vitro. Crucially, however, the great majority of evidence is preclinical (in vitro, in silico and animal), and most bioactivity studies use concentrated leaf or seed extracts rather than the edible flesh. There are essentially no controlled human trials confirming clinical benefit from eating the fruit, so health claims remain unproven in people. Nutritionally the fruit provides modest vitamin C (about 22 mg/100 g) and potassium with little protein, fat or sugar. It is a sensible hydrating, lower-sugar fruit choice, but its medicinal reputation rests on early-stage research. Overall weight of human evidence is preliminary.
Purported Benefits
✓Hydration with a very low calorie load (high water content, ~25 kcal/100 g)
✓Antioxidant / free-radical scavenging activity from polyphenols (preclinical)
✓Antihyperglycemic effects and pancreatic beta-cell protection (preclinical, leaf/fruit extracts)
✓Anti-inflammatory activity (preclinical)
✓Source of vitamin C, which supports normal immune function
✓Cytotoxic chalcones with anticancer activity in cell models (preclinical, isolated seed compounds)
Dosing & Compounds
Typical Dose
1-2 fresh fruits (~85-170 g); eaten raw, skin-on
Active Compounds
Flavonols (myricetin, myricitrin, quercetin glycosides such as guaijaverin, kaempferol)C-methylated chalcones (e.g. 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone, cardamonin)Phenolic acids and ellagitannins (incl. ellagic acid derivatives)Flavan-3-ols / proanthocyanidins ((epi)catechin, (epi)gallocatechin gallate)Vitamin C (ascorbic acid)Potassium, with some calciumTriterpenoids and sterols (betulinic/oleanolic-type)Volatile terpenes contributing aroma
Safety & Cautions
⚠
Generally recognized as safe as a food and well tolerated when eaten fresh. No established drug interactions from culinary amounts, but the concentrated leaf and seed extracts used in research are not validated for human use and should not be assumed safe at those doses. There is a theoretical additive risk with antidiabetic medication (hypoglycemia) given preclinical glucose-lowering activity, so monitor if consuming large amounts of extract. As with any fruit, wash before eating; people with known Myrtaceae (clove, guava, eucalyptus) sensitivities should be cautious. It is not a treatment for diabetes or cancer despite folk claims. Educational only — always check with your doctor or pharmacist before combining Wax Apple with any medicine.
Wax Apple is most often taken for Hydration with a very low calorie load (high water content, ~25 kcal/100 g), Antioxidant / free-radical scavenging activity from polyphenols (preclinical), Antihyperglycemic effects and pancreatic beta-cell protection (preclinical, leaf/fruit extracts), Anti-inflammatory activity (preclinical). Crisp, watery tropical fruit rich in polyphenols
Does Wax Apple work — what does the evidence say?
Preliminary evidence. Early or small human trials; promising but not yet conclusive. Wax apple (Syzygium samarangense), also called java/rose apple or jambu air, is a very watery, low-calorie tropical fruit (~25 kcal/100 g) valued more as a refreshing, hydrating snack than as a dense nutrient source. Laboratory and rodent studies show its leaf and fruit polyphenols (flavonols such as myricetin/myricitrin, C-methylated chalcones, and condensed/ellagitannins) have antioxidant, antihyperglycemic, anti-inflammatory and cytotoxic activities, including protection of pancreatic beta-cells in streptozotocin-diabetic rats and chalcones cytotoxic to colon cancer cells in vitro. Crucially, however, the great majority of evidence is preclinical (in vitro, in silico and animal), and most bioactivity studies use concentrated leaf or seed extracts rather than the edible flesh. There are essentially no controlled human trials confirming clinical benefit from eating the fruit, so health claims remain unproven in people. Nutritionally the fruit provides modest vitamin C (about 22 mg/100 g) and potassium with little protein, fat or sugar. It is a sensible hydrating, lower-sugar fruit choice, but its medicinal reputation rests on early-stage research. Overall weight of human evidence is preliminary.
What is the typical dose of Wax Apple?
1-2 fresh fruits (~85-170 g); eaten raw, skin-on
Is Wax Apple safe? Any cautions or side effects?
Generally recognized as safe as a food and well tolerated when eaten fresh. No established drug interactions from culinary amounts, but the concentrated leaf and seed extracts used in research are not validated for human use and should not be assumed safe at those doses. There is a theoretical additive risk with antidiabetic medication (hypoglycemia) given preclinical glucose-lowering activity, so monitor if consuming large amounts of extract. As with any fruit, wash before eating; people with known Myrtaceae (clove, guava, eucalyptus) sensitivities should be cautious. It is not a treatment for diabetes or cancer despite folk claims.
How many studies support Wax Apple?
NutriDex cites 8 sources for Wax Apple, graded "Preliminary".
Cite this page
APA
Peh, D. (2026). Wax Apple (Syzygium samarangense): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 16 Sept 2026, from https://nutridex.info/s/wax-apple
BibTeX
@misc{nutridex_wax_apple,
author = {Peh, Daryl},
title = {Wax Apple (Syzygium samarangense): Benefits, Dosage, Side Effects \& Evidence},
year = {2026},
howpublished = {NutriDex --- The Supplement Research Compendium},
url = {https://nutridex.info/s/wax-apple},
note = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-09-16}
}
For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.