Health Benefits of Star Fruit

Medically reviewed by Simone Harounian, MS

Star fruit (Averrhoa carambola) is a tropical fruits that is known for its star-like shape. Averrhoa carambola trees are native to Southeast Asia and are also grown in other tropical areas of the world, such as South America and southern Florida.

Star fruit is known for its unique, star-like shape and sweet, slightly tart flavor. They’re a rich source of antioxidants, vitamins, minerals, and fiber, and may benefit health in several ways when enjoyed as part of a well-rounded diet.

Here’s everything you need to know about star fruit, including potential health benefits, nutrition, and how to include star fruit in your diet.

A Source of Anti-Inflammatory and Antioxidant Compounds

Star fruit contains a variety of plant compounds that have powerful antioxidant and anti-inflammatory properties, such as flavonoids, proanthocyanidins,  β‐carotene, and gallic acid.

Consuming foods rich in antioxidants may help improve the body’s natural antioxidant defenses and reduce markers of inflammation, which could improve overall health and lower disease risk.

A 2016 study that included 29 older adults found that drinking 100 grams (g) of fresh star fruit juice twice per day after meals for four weeks led to significant reductions in the inflammatory markers tumor necrosis factor-alpha (TNF‐alpha), interleukin-23 (IL‐23), and nitric oxide (NO)  compared to baseline levels.

In addition to lowering inflammation in the body, consuming star fruit may help boost the body’s antioxidant status. Another 2016 study of 27 older adults demonstrated that consumption of 100 g of fresh star fruit juice twice per day after meals for four weeks resulted in a significant improvement of antioxidant status compared to baseline, including increased total antioxidant capacity, increased levels of the antioxidant nutrients vitamin A and vitamin C,  and reduced levels of oxidative stress markers including malondialdehyde.

Boosting the body’s antioxidant defenses and reducing markers of inflammation and oxidative stress can help lower the risk of diseases associated with oxidative damage, such as heart disease and neurodegenerative diseases.

High in Vitamin C

Vitamin C is a nutrient that has powerful antioxidant properties, meaning it helps protect against cellular damage. Research shows that diets high in vitamin C may help protect against a number of health conditions, including heart disease and several types of cancer.

A 2022 umbrella review that included 57 meta-analyses found that vitamin C consumption was associated with a lower incidence of multiple cancers, including bladder, breast, esophageal, gastric, lung, pancreatic, and prostate cancer. The researchers noted that vitamin C can protect against cancers by reducing oxidative damage to cells and protecting tissues from carcinogens.

Currently, the Institute of Medicine recommends that adult women and men take in 75 and 90 milligrams (mg) of vitamin C per day, respectively. However, the researchers of the review mentioned above argue that this amount is only enough to prevent vitamin C deficiency and isn’t enough to support optimal health. Based on their findings, the researchers suggested that people take in at least 200 mg of vitamin C per day to reduce their risk of chronic diseases, like cancer, and promote overall health.

A large 124-gram star fruit provides 42.7 mg of vitamin C, which covers 50% of the current Daily Value (DV) for vitamin C and 24% of the 200 mg per day expert recommendation.

Beneficial for Heart and Digestive Health

Star fruit is a good source of vitamins, minerals, and fiber, all of which can benefit the health and functioning of the heart and gastrointestinal system.

A large star fruit contains 3.5 g of fiber, which is important for digestive health. Fiber adds bulk to stool and helps promote comfortable and regular bowel movements. Fiber also acts as fuel for beneficial bacteria that reside in the intestinal tract, which helps promote a balanced microbiome and a healthy intestinal lining. Additionally, following a fiber-rich diet could help protect against digestive conditions, such as colon cancer and inflammatory bowel disease (IBD).

Eating fiber-rich foods is also critical for protecting heart health as fiber helps lower blood lipid, blood pressure, and blood sugar levels, all of which can lower your risk of heart disease.

In addition to fiber, star fruit also provides nutrients and phytochemicals that offer protection from heart disease, including vitamin C and flavonoid antioxidants. For example, studies show that increasing your dietary intake of flavonoid antioxidants, such as those found in star fruit, could help lower your risk of coronary heart disease, the most common type of heart disease in the U.S.

Nutritional Facts of Star Fruit

Star fruit is low in calories yet are high in several essential nutrients, such as vitamin C and copper.

Here’s the nutrition information for a large 124-gram (g) star fruit:

• Calories: 38.4

• Fat: <1 g

• Protein: 1.29 g

• Carbohydrates: 8.34 g

• Fiber: 3.47 g

• Copper: 0.17 milligrams (mg) or 19% of the Daily Value (DV)

• Pantothenic acid (B5): 0.485 mg or 10% of the DV

• Vitamin C: 42.7 mg or 50% of the DV

Star fruit is very low in calories but are a good source of fiber, which is important for digestive health, as well as several vitamins and minerals.

Star fruit is an excellent source of vitamin C, with a large star fruit covering 50% of the current DV. Vitamin C functions as a powerful antioxidant in the body and is also necessary for immune function, collagen production, and many other critical processes.

Star fruit also provides copper, which is needed for energy and red blood cell production, and pantothenic acid, a B vitamin that’s necessary for converting food into energy and the production of coenzymes or specialized proteins needed for fatty acid synthesis.

In addition to vitamin C, copper, and pantothenic acid, star fruit also provide smaller amounts of essential nutrients such as folate, potassium, and magnesium.

Risks of Star Fruit

Like most fresh fruits, star fruit is safe to enjoy in moderation. However, certain people should avoid consuming large amounts of star fruit or star fruit juice.

Star fruit contains oxalates, which are naturally occurring compounds found in many plant foods. While small amounts of oxalates aren't harmful to health, consuming high amounts can inhibit nutrient absorption and harm the kidneys. Ingesting large amounts of oxalates can cause calcium oxalate crystals to deposit in the renal tubules, which are parts of the kidneys that are responsible for removing waste and returning important substances to your blood. This can lead to kidney damage and even kidney failure.

A 2022 case study reported that a 78-year-old male with pre-existing diabetes, high blood pressure, and high blood lipid levels suffered acute kidney injury after ingesting three bottles of   concentrated, homemade star fruit juice over one week.

Ingesting too much star fruit or star fruit juice can cause star fruit toxicity, which is characterized by symptoms such as nausea, vomiting, and abdominal discomfort. These symptoms may be followed by decreased urination, which is a sign of kidney damage.

Because star fruit contains oxalates that could harm health when consumed in large amounts, it’s important to enjoy star fruit in moderation and avoid drinking large amounts of homemade star fruit juice.

Tips for Consuming Star Fruit

True to its name, cut star fruit has a star-like shape, which makes it an eye-catching addition to fruit salads, cheese plates, and yogurt parfaits. Ripe star fruit has a sweet, slightly tart taste and a grape-like texture. The entire fruit, including the skin, is edible.

Here are a few ways to enjoy star fruit:

• Use cut star fruit to top yogurt, acai bowls, and oatmeal

• Add cut star fruit to cheese boards and fruit salads

• Add star fruit juice to cocktails and smoothies

• Enjoy it as a snack with nuts or cheese

• Use it as a garnish for cocktails and salads

• Add star fruit juice in marinades, salad dressings, and sauces

Because they’re unique tropical fruits, star fruit may be hard to find in your local grocery store. You may be able to purchase star fruit from specialty grocery stores or order them online.

Ripe star fruit has a short shelf life and should be stored in the refrigerator and enjoyed within a few days of purchase.

A Quick Review

Star fruit is a tropical fruit that has a star-like shape when cut. It has a sweet, slightly tart taste and is rich in several essential nutrients, including vitamin C and copper.

Eating star fruit may benefit health by improving the body’s antioxidant defenses, reducing inflammatory markers, and promoting the health of the digestive system and heart.

However, consuming large amounts of star fruit or star fruit juice can have toxic effects on the body, so they're best enjoyed in moderation.

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