Star Fruit: The Vitamin C Powerhouse that Supports Immunity & Digestion

June 25, 2018
Star fruit - Dr. Axe

by Rachael Link, MS, RD

Sometimes used as little more than a garnish due to its vibrant color and interesting star-like appearance, the star fruit is actually packed with important nutrients and health benefits that make it well worth adding to your plate. It’s high in antioxidants, fiber and vitamin C and has been recognized for its health-promoting properties in a range of recent studies.

Besides its nutrient profile, it’s also incredibly versatile. While many enjoy chowing down on this sweet, juicy fruit as is, it can also be used to add flavor to many different dishes and works well in everything from main dishes to snacks and desserts. And of course, it works on just about any diet, including a fruitarian diet. Hungry for more? Keep reading to learn more about this delicious and nutritious fruit.


What Is Star Fruit?

Star fruit, sometimes called carambola or starfruit, is a type of fruit that comes from Averrhoa carambola, a type of star fruit tree native to Vietnam, India, Indonesia, Nepal, Malaysia and the Philippines.

The flesh of the fruit can range in color from translucent to bright yellow, and it is surrounded by five ridges that resemble a star when cut in a cross section, hence its name. Both the wax-like skin and the juicy flesh of the fruit are edible and are typically consumed raw, but they are sometimes also enjoyed in main dishes and desserts alike. It’s available in both sour and sweet varieties, which are differentiated by their size; sour star fruits tend to be smaller while sweeter types are usually larger.

In addition to being delicious and full of flavor, star fruit is also loaded with many essential nutrients and boasts a long list of health benefits. While research is still ongoing, some in vitro and animal studies show that it may help fight cancer cells, lower cholesterol levels, keep your digestive system running smoothly and reduce inflammation.


Star Fruit Benefits

  1. High in Antioxidants
  2. May Have Anticancer Properties
  3. Lowers Cholesterol
  4. Boosts Immunity
  5. Supports Digestive Health
  6. Reduces Inflammation

1. High in Antioxidants

Star fruit is an awesome source of antioxidants, which are compounds that fight free radicals and help enhance health. Studies show that antioxidants may come with a long list of health benefits and can help protect against chronic conditions, including heart disease, diabetes and cancer. (1)

In particular, star fruit is high in several specific plant compounds and polyphenols with powerful antioxidant properties, including quercetin and rutin. (2) In vitro and animal models have found that quercetin may help boost physical and mental performance while rutin is believed to benefit both brain and heart health. (3, 4)

2. May Have Anticancer Properties

Jam-packed with antioxidants, it should come as no surprise that some studies have reported that this nutrient-dense fruit may have powerful anticancer properties.

Although current research is limited, one 2014animal model from the Radiation & Cancer Biology Laboratory at the University of Rajasthan’s Department of Zoology in India found that administering an extract of star fruit helped protect against liver cancer in rats. (5) Some of the specific compounds found in the fruit have also been shown to be effective against cancer, such as quercetin, which has been shown to block cancer cell progression in some in vitro studies. (6) More research is still needed, however, to determine the potential effects of star fruit on cancer in humans.

3. Lowers Cholesterol

Although cholesterol is a vital part of health, having too much can cause it to build up in your bloodstream, hardening your arteries and upping your risk of heart disease. Interestingly, preliminary in vitro and animal studies have found that some of the compounds found in star fruit could help reduce cholesterol levels to keep your heart healthy and strong.

It’s well-established that fiber can help lower levels of bad LDL cholesterol, which can help reduce the risk of coronary heart disease. (7) In fact, one study published in the International Journal of Food Sciences and Nutrition out of Mexico found that insoluble fiber extracted from star fruit helped reduce high triglycerides and cholesterol levels in mice. (8)

4. Boosts Immunity

Just one medium star fruit can knock out up to 52 percent of your vitamin C requirement, putting it right on par with foods like oranges, lemons and limes when it comes to enhancing immune health.

According to one study out of Switzerland published in the Annals of Nutrition & Metabolism, getting enough vitamin C in your diet could help shorten the duration of respiratory tract infections like the common cold while also reducing the severity of symptoms. Vitamin C may also help protect against other conditions, including malaria, pneumonia and diarrhea infections. (9)

Not only that, but this fruit is also rich in antioxidants, which can protect the cells against oxidative damage to reduce the risk of inflammation, infections and chronic disease.

5. Supports Digestive Health

Star fruit is loaded with fiber, which can help give your digestive system a healthy boost. Add just one star fruit into your diet and you’re already meeting up to 10 percent of your daily fiber needs in one shot.

Fiber moves slowly through the body undigested and helps to increase stool bulk and prevent constipation. (10) In addition to supporting regularity, fiber has also been shown to play a central role in other aspects of digestive health as well. It helps promote the health of the gut microbiome and may be beneficial in the treatment and prevention of conditions like diverticulitis, hemorrhoids, intestinal ulcers and acid reflux. (11, 12)

6. Reduces Inflammation

While acute inflammation is an important immune process designed to help protect the body against foreign invaders, chronic inflammation can actually be harmful to health. Sustaining inflammation over the long term has been connected to many chronic diseases, including heart disease and autoimmune disorders. (13)

Star fruit is rich in antioxidants that work to reduce oxidative stress and relieve inflammation. A 2016 animal model out of Brazil and published in the International Journal of Biological Macromolecules also showed that extracts of star fruit helped reduce inflammation in mice, which could potentially help to decrease inflammatory-related pain caused by conditions like rheumatoid arthritis. (14)

 

Star fruit - Dr. Axe

 


Star Fruit Nutrition

Star fruit is low in calories but loaded with vitamin C and fiber along with an array of other select vitamins and minerals.

One medium star fruit contains approximately: (15)

  • 28 calories
  • 6.2 grams carbohydrates
  • 0.9 gram protein
  • 0.3 gram fat
  • 2.5 grams dietary fiber
  • 31.3 milligrams vitamin C (52 percent DV)
  • 0.1 milligram copper (6 percent DV)
  • 0.4 milligram pantothenic acid (4 percent DV)
  • 121 milligrams potassium (3 percent DV)
  • 10.9 micrograms folate (3 percent DV)

In addition to the nutrients listed above, star fruit also contains a small amount of niacin, manganese and magnesium.


Star Fruit in Ayurveda and TCM

With its wide array of nutrients and antioxidants, the health-promoting properties of star fruit can be easily incorporated into both Traditional Chinese Medicine and Ayurveda.

In Traditional Chinese Medicine, it is considered a cooling fruit along with other foods, such as grapefruit, seaweed, tomato, watermelon and chestnut. This means that it has a cooling effect, which can help provide balance to the body. Foods with a cooling effect are sometimes used to alleviate symptoms like chronic thirst, constipation, headaches, cold sores and heartburn.

Meanwhile, on the Ayurvedic diet, star fruit is believed to help treat conditions like cold and cough as well as digestive disorders like irritable bowel syndrome. It’s considered light and easy to digest, making it a great fit for kapha and vata doshas in particular.


Star Fruit vs. Kiwi

Kiwi fruit and star fruit definitely share some similarities in several different aspects. They’re both considered tropical fruits, they’re both native to different parts of Asia, and they’re both equally delicious and nutritious.

That being said, there are also some definite differences that set them apart. First of all, they each belong to entirely different plant families, and kiwi fruit actually grows on woody vines rather than trees like the star fruit. While star fruit stands out for its star-like shape and vibrant yellow hue, kiwi fruit is small and round with brown skin, bright green flesh and small black seeds.

In terms of nutrition, kiwi packs in more calories but also provides a greater wealth of nutrients. Gram for gram, kiwi supplies more fiber, vitamin K, vitamin E, folate and potassium than star fruit, plus contains nearly triple the amount of vitamin C. However, both are a great source of antioxidants and can be healthy additions to a nutritious and well-rounded diet.


Where to Find and How to Eat Star Fruit

Finding star fruit can be tricky, especially if you live in an area where it’s not commonly grown. You may be able to find it in the produce section of your local grocery store alongside other tropical fruits, such as dragon fruit, mangoes and coconuts. You may also need to look a little further and search in your nearest farmers market or specialty store if you’re having trouble finding it.

When purchasing this fruit, look for one that’s firm with an even color free of brown spots. Picking a fruit that is bright yellow ensures that it has reached peak ripeness and is ready to enjoy.

At first glance, many people are unsure about how to cut star fruit. Fortunately, it’s easier than it looks. Simply wash it thoroughly to remove extra dirt, and then use a knife or vegetable peeler to cut off the green or brown edges of the fruit. Cut the two ends, and then slice along the widest side of the fruit to create thin, star-like slices that are approximately half an inch thick. Although the seeds are edible, you can also pop them out while cutting your the fruit if you’d prefer.

Wondering how to eat a star fruit? Because of the unique star fruit taste, it can be enjoyed raw or added to a variety of dishes. It’s sometimes cooked like a vegetable, dried or even pickled. It’s also used in recipes to make everything from salsa to smoothies or seafood dishes, all based on your personal preference.


Star Fruit Recipes

Although it’s often enjoyed all on its own, there are plenty of other interesting ways to enjoy this delicious fruit as well. From adding it to juices or smoothies to including it as part of a nutritious snack or main course, the options are limitless with just a little creativity. Here are a few simple recipes to get started:


History

Although it’s been cultivated for centuries in Southeast Asia, it’s unclear exactly where or when the star fruit originated. According to some sources, Sri Lanka, Indonesia or Malaysia are a few of the most likely sources of origin. Like other fruits native to Asia, such as monk fruit or jujube fruit, star fruit has long been recognized for its health-promoting properties.

In recent years, it has gained widespread popularity and is now known by many names around the world. Star fruit in Spanish, for example, is often called tamarindo chino, tamarindo culi and fruta china. Meanwhile, it’s known as belimbing in Indonesian, saranate in Tagalog, sternfrucht in German and stjärnfrukt in Swedish.

Today, some of the top producers of this fruit include countries like Australia, India, Malaysia, Israel, the Philippines, Taiwan and the United States. However, star fruit is enjoyed and appreciated for its unique flavor and impressive health benefits all over the globe.


Precautions

Despite the many impressive benefits of star fruit, it may not be a great dietary addition for everyone. While it can be a great way to amp up your intake of vitamin C and fiber, there are certain groups of people who should avoid this fruit altogether.

Star fruit, and sour varieties in particular, are high in oxalates, compounds found in certain foods that can increase the risk of kidney stones for some individuals. Consuming large amounts of star fruit has also been linked to kidney damage in some case reports. (16) Plus, one review out of Brazil even noted that eating star fruit can cause neurotoxicity in patients with chronic kidney disease, thanks to the presence of a specific toxin found in the fruit. (17) Therefore, if you have any kidney problems, it’s best to steer clear of star fruit until consulting with your doctor.

Additionally, star fruit can alter the way that certain drugs are metabolized in the body by inhibiting the activity of several key enzymes. If you’re taking any prescription medications, check with your health care provider to ensure that eating star fruit is safe for you.


Final Thoughts

  • Star fruit, also known as carambola or starfruit, is a type of fruit native to Vietnam, India, Indonesia, Nepal, Malaysia and the Philippines.
  • It stands out for its bright yellow flesh and distinct star shape as well as its unique sweet and sour flavor varieties.
  • Star fruit is low in calories but loaded with fiber, antioxidants and vitamin C. It also contains a small amount of copper, pantothenic acid, potassium and folate.
  • While human studies on the effects of star fruit are limited, some research suggests that it may help lower cholesterol levels, improve digestive health, fight inflammation and boost immunity. It may also contain anticancer properties thanks to its high antioxidant content.
  • Star fruit is full of flavor, easy to prepare and can be enjoyed in a variety of different recipes, making it an excellent addition to a well-rounded and balanced diet.

Read Next: Persimmon Fruit: The Vitamin A Fruit that Benefits Cholesterol Levels


From the sound of it, you might think leaky gut only affects the digestive system, but in reality it can affect more. Because Leaky Gut is so common, and such an enigma, I’m offering a free webinar on all things leaky gut. Click here to learn more about the webinar.

Josh Axe

Get FREE Access!

Dr. Josh Axe is on a mission to provide you and your family with the highest quality nutrition tips and healthy recipes in the world...Sign up to get VIP access to his eBooks and valuable weekly health tips for FREE!

Free eBook to boost
metabolism & healing

30 Gluten-Free Recipes
& detox juicing guide

Shopping Guide &
premium newsletter

More Foods

Sponsored