This tropical fruit has many names and just as many nutrients. It contains powerful antioxidants, it tastes delicious, and it may speed up the metabolism. Read on to find out whether you should add passion fruit to your diet.
What Is Passion Fruit?
Passion fruit is a purple or yellow tropical fruit that grows on the vine of several members of the Passiflora genus, most notably Passiflora edulis. Besides “passion fruit,” it has many names, including maracuya in Spanish, maracuja in Portuguese, and lilikoi or liliko’i in Hawaiian [1].
Passion fruits have a tart, almost sour flavor. Unsurprisingly, the fruits get sweeter and less tart the riper they are [2].
Passion fruit has a handful of uses in traditional medicine. Among the Kalenjin people of Kenya, pregnant women eat passion fruit in the believe that it will increase their blood volume, help with appetite and digestion, and improve the skin of the baby after birth. In South America, passion fruit is a traditional tonic for anxiety, insomnia, asthma, bronchitis, and urinary tract infection [3, 1].
The edible part of the passion fruit is the juicy, pulpy interior. Somewhat like a pomegranate, passion fruit has many seeds, each surrounded by a casing of sweet flesh. Passion fruit seeds are edible and contain a powerful antioxidant called piceatannol [1, 4].
Passion fruit is healthy, nutritious, and delicious.
Varieties
The most important varieties of passion fruit are the purple (Passiflora edulis f. edulis) and yellow passion fruit (Passiflora edulis f. flavicarpa) [2, 5].
Of these, the yellow passion fruit is larger, hardier, and more often used for juice production, but the purple passion fruit is sweeter and more aromatic. They are both round fruits with thick skins; they contain many seeds encased in sweet flesh [2, 5].
A third type of passion fruit, the so-called banana passion fruit, is long (shaped like a banana or a zucchini) whereas the classic yellow and purple passion fruits are round. Banana passion fruits are actually the fruits of multiple closely related species (including Passiflora tarminiana and Passiflora mollissima) [6, 7].
Snapshot of Passion Fruit
Proponents:
- Delicious, healthy, and very safe
- Peel and seeds may reduce inflammation
- Seeds prevent the formation of new fat tissue
- Seeds lower blood sugar and prevent insulin resistance
- Fruit improves gut flora
- Supports heart, liver & kidney health
- Seed oils soften the skin
Skeptics:
- Limited studies on health benefits in humans
- Peel extract & flour are very difficult to find and buy
- Some people find the smell of the seed oil unpleasant
Passion Flower Nutrition Facts
According to the United States Department of Agriculture, 100 g of purple passion fruit has 97 calories, 11.2 g of total sugars and 10.4 g of dietary fiber. Purple, yellow, and banana passion fruits also contain significant amounts of [8, 6]:
- Vitamin C (up to 46% of the daily recommended value in 100 g)
- Vitamin B3 (niacin)
- Provitamin A
- Phosphorus
- Potassium
- Iron
- Magnesium
The mineral content of passion flower, which produces the fruit, varies based on the mineral content of the soil it grows in. One study found significantly higher calcium and magnesium levels in fruits fertilized with cattle manure as opposed to a synthetic mineral fertilizer [9].
Passion fruit rind and peel have been studied as a potential source of dietary fibers that can be used to enrich other foods. Passion fruit peel can be milled into a flour that contains between 25% and 37% soluble fiber [10, 11].
Active Compounds
The flavonoids found in passion fruit and banana passion fruit include:
- Proanthocyanidins, and
- Flavan-3-ols
These antioxidant phenolics are also abundant in cranberries; they are thought to be the reason why cranberries are good for preventing urinary tract infections (UTIs) [6, 12, 13].
In one review of 24 exotic fruits, banana passion fruits were found to have the most antioxidant activity and the highest concentration of phenolic compounds [7].
Passion fruits contain significant amounts of alpha and beta carotene in both the pulp and peel. Your body uses dietary beta carotene to make vitamin A, an essential nutrient [14].
Purple passion fruit peel and seeds contain considerably more anthocyanins than those of other varieties. Anthocyanins improve the health of many organs and systems, including the heart, brain, eyes, and liver. They may also delay diabetes and reduce inflammation [14, 15].
Passion fruit seeds and seed extract are rich in an antioxidant stilbenoid called piceatannol. Similar to resveratrol, piceatannol improves insulin sensitivity and may reduce blood pressure and heart rate [4, 16].
Passion fruit is also a significant source of bioactive amines (like spermine and spermidine), which scavenge free radicals and reduce oxidative stress [17].
Potential Benefits with Insufficient Evidence
Passion fruit has produced positive results for these benefits in at least one study, but larger and more robust studies are required to confirm or refute its effectiveness. Passion fruit and its products are considered safe to consume as food, but the FDA has not approved it for any medical purpose or health claim, and there is no guarantee of the quality of any given product or supplement.
Passion fruit is often studied as part of a whole fruit or extract, with a mixture of bioactive compounds that carry its overall benefits [18].
1) Arthritis
In a study of 33 people with osteoarthritis of the knee, 150 mg per day of purple passion fruit peel extract significantly improved pain, freedom of movement, and physical function. Unfortunately, the study only tested a single dosage for about two months [19].
2) Asthma
Proanthocyanidins in passion fruit may help people with allergic asthma by reducing inflammation in the airway. Interestingly, some South American traditions used passion fruit to manage asthma and bronchitis [20, 1].
In one human trial, an extract of purple passion fruit peel improved the symptoms of people with asthma. People who took 150 mg per day of the extract had less wheezing, coughing, and shortness of breath compared to no improvement from the placebo. None of the participants suffered any side effects from the extract [21].
3) Diabetes
We can also go slightly off the beaten trail for antidiabetic effects. Yellow passion fruit peel can be milled into a flour that improved insulin sensitivity in people with diabetes [22].
A closely related species of wild passion fruit (Passiflora ligularis) – also known as sweet granadilla – may also be a source of medicinal compounds [23].
In a study of diabetic rats, water extracts from sweet granadilla fruit brought blood sugar and blood protein levels back to near normal. Extracts also boosted antioxidants like glutathione, vitamin C, and vitamin E. The fruit extract was nearly as strong as glibenclamide, a diabetes medication [23].
4) Softens Skin, Nails & Hair
Passion fruit seed oil, often sold under the name “maracuja oil,” is rubbed into the skin, nails, and hair to soften them and prevent breakage. A blend of passion fruit seed, raspberry seed, and peach kernel oils increased the oiliness and hydration of human skin without adverse effects. Maracuja oil also has a strong cultural history of use in curly, coarse hair [24].
Be sure to buy the oil from a trusted company with consistently good reviews to avoid disappointment.
Animal Research (Lacking Evidence)
No clinical evidence supports the use of any passion fruit products for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies listed below should not be interpreted as supportive of any health benefit.
5) Inflammation
The antioxidant cocktail in passion fruit may have a significant anti-inflammatory effect.
In a cell study, piceatannol, most abundant in the seeds, significantly reduced inflammatory cytokines released by white blood cells (macrophages) in fat tissue. Low-grade chronic inflammation caused by these white blood cells in fat tissue can lead to chronic diseases [25, 4].
Some researchers believe that combinations of anthocyanins, such as those in purple passion fruit, may help manage chronic low-grade inflammation in obese people [18, 14].
What’s more, piceatannol in passion fruit increases the activity of an antioxidant protein (HO-1) that blocks inflammatory molecules (TNF-a, IL-6, and NF-κB) [26].
Plus, anthocyanins – found in purple passion fruit peel and seeds – similarly lower inflammatory compounds (IL-6 and other cytokines) [18].
And curiously, these exotic fruits also contain polyamines. We know little about polyamines, but their excessive breakdown has been linked to oxidative stress, aging, and inflammation. Passion fruit (especially unripe fruits) may help restore polyamine levels in the brain, liver, and kidneys [27, 28, 17].
6) Metabolic Health
According to some researchers, different parts of passion fruit may be used to manage metabolic disease and obesity. Piceatannol, found in the fruit seeds, is especially promising: it may prevent the formation of new fat tissue, reduce blood sugar, and prevent insulin resistance [26].
Gut Flora
Proanthocyanidins, such as those in the fruit flesh, improved the composition of gut flora in mice fed a high-fat diet. They might work by preventing harmful bacteria from colonizing the wall of the gut. This effect has not yet been confirmed in humans [29, 30].
Anthocyanins, meanwhile, reduced inflammation in fatty tissues in obese rats [18].
How It Could Work
Passion fruit might disrupt deep-rooted fat-building pathways in the body.
Piceatannol, the major antioxidant in passion fruit seeds, blocks fat production and enhances energy metabolism. It works by blocking several fat growth pathways (including Akt, insulin signaling, ERK, and possibly PI3K). All together, this helps prevent new fat from forming [26].
Piceatannol also activates AMP-activated protein kinase (AMPK), a key fat- and sugar-burning enzyme. AMPK prevents the formation of new fat tissue and speeds up the rate at which sugars and fats are burned. This enzyme also lowers blood sugar, making it an excellent target for diabetes management [26, 31].
7) Supports Heart Health
Passion fruit, and especially the seeds, may support heart health by lowering blood pressure, fats, and oxidative stress.
In animals, the main active compound in passion fruit (piceatannol) relaxed the blood vessels, stabilized the heartbeat, and prevented the growth of unneeded new blood vessels. In rats, it also helped keep the heart muscle healthy despite weight gain [32, 26].
Additionally, large doses of the pulp of yellow passion fruit reduced blood pressure and oxidative stress in rats [33].
8) Supports Liver & Kidney Function
In a very recent rat study, the peel extract of passion fruit protected the liver and kidneys from damage from toxic chemicals. Of three varieties tested, purple passion fruit had the best protective effect [34].
As mentioned above, the peel can also be milled into flour and seems to be good for people with diabetes [22].
Enthusiasm aside, the above rat study was published in 2019. Human trials are still lacking to back up their results. Meanwhile, passion fruit peel extracts or flour are not yet widely available.
Passion Fruit Side Effects
Passion fruit is considered very safe – about as safe, in fact, as other commercial, edible fruits. In rats, doses of up to 8 g per kg of body weight per day were highly beneficial, with no adverse effects reported [33].
People with latex allergies are sometimes also sensitive to other plant-based proteins, including some found in passion fruit. If you have a latex allergy and you’ve never eaten a passion fruit, you may want to avoid them. At the very least, be aware of the risk [35].
The most potentially dangerous compounds in passion fruit are the cyanogenic glycosides. In the body, these compounds release hydrogen cyanide, a highly toxic chemical. Fortunately, passion fruit does not contain enough cyanogenic glycosides to be worrying. Other foods that have far more include bitter almonds and uncooked cassava [36, 37, 38].
Limitations and Caveats
Unfortunately, there are few human studies on the health benefits of the whole passion fruit or fruit extract. While the chemical composition of passion fruit is fairly well established, each of its components is often studied in the context of other fruits and vegetables.
Passion fruit peel has shown the most direct therapeutic potential. In a handful of human studies peel flour and extracts reduced blood sugar and inflammation. However, peel flour and extract are extremely difficult to find and buy, so the usefulness of this research is currently very limited.
How to Eat & Use Passion Fruit
Passion Fruit Juice & Purée
Passion fruits can be eaten raw, juiced, or puréed.
When picking passion fruit, approach it similar as you would other fruits. The darker its color and softer to touch, the riper it is. The color will also depend on the variety (yellow, red, or purple), but green fruits are unripe. The skin should be smooth and free of large wrinkles and bruises.
To eat the fruit, simply wash it and cut in half with a knife. Scoop out the contents with a spoon and eat straight up or add to your smoothie.
The juice and purée found in stores often have sugar or other sweeteners added because of the tart flavor of the unprocessed fruit. But these are the least processed forms of passion fruit available.
The fruit and purée are often added to drink and dessert recipes to give a tropical kick to a sweet treat. These aren’t the healthiest ways to consume passion fruit, but they sure are tasty!
Others like to add passion fruit to savory dishes as well, such as meat or fish. It adds a distinct flavor when mixed into various sauces and dressings.
Tea, Syrup, Jam & Extracts
A few more steps of processing produces tea, syrup, jam, and extracts. Dried fruit can be added to blended tea to give it a fruity, acidic flavor. Sugary passion fruit syrup is added to carbonated water, iced tea, or other drinks. Jams and jellies can also be heavily sweetened.
The more sugar is added to the fruit, the less of a benefit you’re likely to see – especially when it comes to antidiabetic effects.
Passion fruit extracts are rarer, and they tend to be marketed as a flavoring for baked goods and fancy desserts. Passion fruit peel extract and peel flour have been the recent subject of research, but they are very difficult to find.
Maracuja Oil & Butter
Passion fruit seed oil and seed butter are usually sold under the name maracuja, which is the Portuguese name for passion fruit. These forms are marketed as moisturizers for the skin, hair, and nails.
How Much to Take
Research tells us very little about how much passion fruit its best to eat.
Much of the clinical research specifically focused on the peel extract and flour. They have found that:
- 150 mg of peel extract per day reduced symptoms of asthma [21].
- 150 mg of peel extract per day reduced symptoms of osteoarthritis of the knee [19].
- 30 g per day of peel flour per day improved insulin sensitivity in people with type 2 diabetes [22].
Takeaway
Passion fruit may be underused in the world of functional food. The flesh, peel, rind, and seeds all contain many bioactive compounds that may fight obesity, lower blood sugar, reduce inflammation, and support the heart, liver, and kidneys. Plus, it’s low in calories.
You can eat the fruit whole, juiced, or puréed. The dried fruit makes a great addition to black or herbal tea. It is also used to make syrups, jams, sauces, and extracts.
The seed oil, often called maracuja oil, is considered an excellent moisturizer for skin and coarse, curly hair.
