Star fruit, known locally as มะเฟือง, is a staple in Thai markets and home gardens. Its tart-sweet flavor, star-shaped slices, and refreshing crunch make it a beloved treat. The fruit has attracted global attention for its nutrition and potential health benefits, but there are also important risks for certain groups. This balanced view helps Thai readers enjoy star fruit safely.
Star fruit is low in calories yet rich in nutrients. A medium fruit (about 91 grams) provides around 28 calories, 3 grams of fiber, and 1 gram of protein. It also delivers a significant portion of the daily vitamin C requirement, along with smaller amounts of folate, vitamin B5, copper, potassium, and magnesium. Its antioxidant compounds—such as vitamin C, gallic acid, epicatechin, and quercetin—help fight free radicals and may support heart and liver health. While animal studies hint at anti-inflammatory and cholesterol‑improving effects, robust human evidence is still needed to confirm these benefits.
In Thai and broader Asian traditional medicine, star fruit has long been used to ease sore throats, fevers, and coughs, and to aid digestion. Scientific reviews confirm that extracts from the fruit, leaves, and roots contain saponins, flavonoids, alkaloids, and tannins that contribute to anti-inflammatory, antimicrobial, antiulcer, and antioxidant properties. Animal studies have shown reduced skin inflammation with star fruit extract, and some laboratory work suggests activity against common bacteria, including Staphylococcus aureus and Escherichia coli. Data from Thai and international research supports these traditional uses, while noting the need for more human studies to confirm efficacy and safety.
A study involving elderly adults in northern Thailand found that drinking star fruit juice (about 100 grams twice daily for a month) improved antioxidant status and lipid profiles, with higher HDL and lower LDL. Participants also showed reduced markers of oxidative stress and inflammation, factors linked to aging and chronic diseases such as hypertension and diabetes. Importantly, the study reported no short-term liver or kidney harm in healthy older adults, though researchers cautioned that long-term safety and oxalate levels were not assessed.
However, star fruit carries a notable health risk for kidney patients. The fruit is high in oxalates, especially the sour varieties. In susceptible individuals, oxalate can accumulate and damage kidney function. People with kidney disease or reduced kidney function may experience acute kidney injury after consuming even small amounts of star fruit, with symptoms like vomiting, hiccups, confusion, seizures, or even coma. In healthy individuals, excessive consumption can also lead to oxalate nephropathy requiring hospitalization or dialysis. While most people recover fully, these cases underscore the importance of moderation.
The risk is heightened when star fruit is used as a home remedy for blood sugar control in diabetes, a group already at higher risk of kidney issues. There have been regional reports linking kidney injury to frequent star fruit consumption. Medical professionals advise that individuals with diabetes, kidney disease, or those on dialysis should avoid star fruit and its juice. Public health messaging should emphasize this guidance for Thai communities.
Beyond oxalates, star fruit can interact with certain medications. Some compounds may inhibit liver enzymes that metabolize drugs, potentially altering drug levels and effects. If you take prescription medications—especially for chronic conditions—consult your healthcare provider before adding star fruit to your diet.
For healthy individuals, moderation is key. Thai and international guidelines suggest enjoying star fruit as part of a varied, balanced diet—one or two fruits per day, accompanied by other fruits and vegetables. Pregnant or breastfeeding women, children, people with a history of kidney stones, and older adults should exercise extra caution or seek medical advice. Avoid undiluted sour juice in large quantities or on an empty stomach, which can increase oxalate absorption. Thorough washing before consumption helps reduce pesticide residues and bacteria. Given stories of home preparations using large quantities, public education on safe preparation and moderation remains important.
Star fruit is deeply embedded in Thai culture—featured in seasonal celebrations, home gardens, and folklore. Yet as Thailand faces rising rates of chronic disease, it is essential to pair traditional knowledge with current medical guidance. Health authorities and educators should continue outreach to high-risk groups, ensuring that star fruit’s benefits are enjoyed safely.
Future research offers hope that star fruit’s therapeutic potential could be enhanced through selective breeding or processing to reduce oxalate and caramboxin content. Advances in biotechnology and deeper study of its antioxidant and anti-inflammatory properties may broaden its role in preventive nutrition, not only in Thailand but across tropical regions.
In conclusion, star fruit can contribute to a nutritious diet for healthy individuals, supporting immunity and metabolism when enjoyed in moderation. However, it poses serious risks for those with kidney disease, kidney stones, or reduced kidney function, and may interact with certain medications. Thai consumers should prioritize moderation, variety, and informed decisions—consult a healthcare provider if you have underlying health issues, avoid unverified online health advice, and share knowledge with family and friends to keep star fruit a safe and cherished part of Thailand’s dietary culture.
Notes on context and attribution:
- Nutritional and antioxidant profiles reflect current nutrition science and Thai dietary context.
- Traditional uses and animal studies support plausible benefits, with clear calls for more human research.
- Kidney toxicity risk is supported by clinical observations and nephrology literature.
- Drug interaction potential aligns with known enzyme-inhibition effects observed in related food research.
- Guidelines align with Thai and international nutrition recommendations for fruit consumption.