The jackfruit tree (Artocarpus heterophyllus) produces the largest known edible fruit in the world. All parts of the plant (seed, leaf, pulp, root bark, and stems) have been studied extensively for their antioxidant, anti-diabetic, and immune-boosting properties, but the clinical research is scarce. Keep reading to learn about the benefits, nutrition facts, and side effects of jackfruit.
What is Jackfruit?
Jackfruit, also known as jack tree, fenne, or sometimes simply jack, is related to breadfruit and originated in India. It is part of the mulberry or fig family, found in tropical and subtropical regions worldwide including Southeast Asia, Africa, and Brazil [1, 2].
The jackfruit fruit contains fleshy bulbs and starchy seeds, both of which are used as food. This tree produces the highest yield and largest known edible fruit (average weight of 10 kg) than any other fruit tree species [3, 4].
Jackfruit is rich in phytonutrients such as phenols and flavonoids and has been studied for its potential antioxidant, anti-inflammatory, antibacterial, anticancer, and antidiabetic qualities [5, 6, 7, 8, 9, 10].
Snapshot
Proponents:
- Great nutritional value
- Boosts immunity
- Lowers blood sugars
- Combats pathogens
- May reduce inflammation and oxidative stress
Skeptics:
- Clinical evidence is scarce
- Some people may be allergic
- May interact with blood thinners
Components
Jackfruit pulp has many valuable micronutrients including [11]:
Raw jackfruit flesh is a good source of carbohydrates. A 100 g portion has 94 calories, 23 g carbohydrate, and 1.5 g fiber. This fiber content is believed to contribute to the jackfruits’ relatively low blood sugar response when compared to sugar and other tropical fruits [4, 11, 12].
One 100 g portion of jackfruit flesh can provide up to 25% of the recommended daily amount of niacin (vitamin B3), a key vitamin in energy production, nerve function, and hormone production [11].
The jackfruit seed can be boiled or roasted and preserved in syrup like chestnuts, or ground into a meal and blended with wheat flour. The pulp and seed are often ground together into a meal commonly eaten in Sri Lanka [11, 4].
Health Benefits
1) Improves Blood Sugar Control
In a pilot trial, jackfruit leaf extracts taken as a tea (20g/kg body weight) improved blood sugar tolerance in normal and diabetic patients [13].
Treatment of healthy and diabetic rats with jackfruit leaf or stem bark extracts lowered fasting blood sugar levels, improved tolerance to sugar, and/or increased blood insulin levels. This antidiabetic activity was due to the high flavonoid content in the jackfruit extracts [10, 14, 15, 16].
Plant flavonoids, like quercetin, are present in large amounts in both the jackfruit leaf and seed and are likely responsible for the fruit’s antidiabetic activity [17].
2) Boosts the Immune System
Phenols, flavonoids, and lectins in the jackfruit are the most promising compounds to strengthen the immune system and suppress cancer cells. These phytochemicals are produced in the jackfruit fruit, peel, seeds, and wood [18, 19, 20].
Jackfruit seed lectins increased white blood cells (mast cells) in the bone marrow of rats, suggesting a role for this extract in stimulating immune response [21].
They activated an immune response against introduced pathogens by stimulating white blood cell production (mast cells and neutrophils) and increasing inflammatory cytokines (IL-17) in the lab and in rats [22, 21, 23].
Jacalin, a lectin extracted from jackfruit seeds, reduced precancerous lesions in mice with early stages of colon cancer [19].
Phenol-rich extracts from different parts of jack tree or fruit suppressed different types of cancer cells in test tubes, but this doesn’t tell us anything about their actual anticancer effects in living organisms [1, 18, 24, 25, 26, 20, 27, 28].
Despite the promising preclinical research, we can’t make any conclusions in the lack of clinical evidence.
3) Combats Pathogens
Bacteria
Extracts from the root bark, pulp, leaves, and stems of jackfruit have broad-spectrum antibacterial activity against numerous gram-positive and gram-negative bacteria.
They include the strains causing tooth decay (Streptococcus mutans, Porphyromonas gingivalis) and strep throat (Streptococcus pyogenes), as well as foodborne pathogens (Listeria and Salmonella species, Escherichia coli) [29, 7, 30, 31, 32].
Flavonoids from jackfruit wood (artocarpin) slowed the growth of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli bacteria in the lab. They also enhanced the antimicrobial activities of several synthetic antibiotics (tetracycline, ampicillin, and norfloxacin) likely by altering the membrane permeability of the bacteria [33, 34].
In the lab, extracts from jackfruit latex slowed the growth of Pseudomonas aeruginosa, a bacteria associated with antibiotic resistance [35].
Viruses
Jacalin, a jackfruit lectin, blocked human immunodeficiency virus (HIV) infection of immune system cells by binding to the surface of CD4, an immune cell and known receptor for the HIV [36, 37].
In test tubes, jackfruit extracts suppressed 2 herpes viruses (herpes simplex 2 and varicella-zoster) and cytomegalovirus [38].
Fungi
In the lab, lectins extracted from jackfruit seeds slowed the growth of three fungi (Fusarium moniliforme, Saccharomyces cerevisiae, and Paracoccidioides brasiliensis). The lectins stimulated an immune response by increasing inflammatory cytokines (IL-12), which killed the invading fungus [29, 39].
Purified enzymes extracted from jackfruit inhibited the growth of Candida albicans, a harmful yeast common in the human gut [35].
Parasites
Jackfruit lectins increased the elimination of the parasite Leishmania major from human white blood cells (neutrophils). The lectins increased mediators of cell inflammation (TNF-α and IL-1β), pancreatic enzymes (elastase), and elevated antimicrobial activity in the cells [40].
Truth be told, researchers tested antimicrobial effects of jackfruit components in test tubes only, and these results may not translate to human beings and other living organisms.
4) Has Antioxidant Effects
Three flavonoid antioxidants extracted from jackfruit reduced fat breakdown in rat brains by scavenging free radicals [41].
The antioxidant activity of jackfruit is linked to its phenolic and flavonoid content. These compounds are high in the jackfruit peel but also present in the fruit pulp, roots, twigs, and leaves [42, 43, 5, 44, 14, 28, 45, 46].
According to several studies, the high vitamin C, phenol, and flavonoid content of the jackfruit are correlated with its protective effects against free radicals involved in the development of diseases such as cancer [11, 47, 48].
5) May Reduce Inflammation
Jackfruit peel extracts inhibited the COX-1 inflammatory mediator in rats in a way that was comparable to the standard anti-inflammatory drug, diclofenac [49].
In test tubes, jackfruit peel extracts and isolated flavonoids inhibited mediators (COX-1 and 2, nitric oxide, IL-1β, IL-6, TNF-α) associated with inflammation and septic shock [49, 6, 50, 42].
6) Supports Wound Healing
Jackfruit leaf extracts had the same wound healing activity as a pharmaceutical-grade antiseptic cream (Betadine) in healthy mice [51].
Out of 98 plant extracts tested in the lab, jackfruit showed the greatest potential for wound healing activity as measured by its ability to increase prostaglandin-2 levels, an important molecule that accelerates wound healing [52].
7) May Improve Digestion
The high fiber content in jackfruit pulp may help prevent constipation and support healthy bowel movements [11].
Jackfruit seed contains prebiotic fiber that may support the growth and activity of beneficial bacteria in the digestive system [11].
8) May Support Heart Health
Jackfruit leaf extracts decreased total cholesterol, LDL cholesterol, and triglycerides, and increased HDL cholesterol in type 2 diabetic mice. This was likely due to the high content of antioxidant flavonoid in the extracts, specifically quercetin [14].
Limitations and Caveats
Most of the benefits of jackfruit were only studied in animals and cells. While the findings are significant, they may or may not apply to humans, and these extracts need to be further evaluated for effects, optimal dose, long-term safety, and potential side effects.
Jackfruit Side Effects & Precautions
There may be a higher likelihood of a jackfruit allergy if a birch pollen or latex allergy is present. This is because of the similarity of allergens present in jackfruit, natural latex, and pollen [53, 54, 55].
Lectins extracted from jackfruit seeds can stimulate the immune system. This could negatively impact patients with tissue transplants or immunosuppression therapy [56].
Although not well studied in humans, jackfruit may impact blood coagulation and should be used with caution in people with blood disorders [57].
How to Eat Jackfruit
Ripe jackfruit fruit is sweet and eaten raw. It can be added to smoothies or mixed with yogurt or ice cream. Seeds can be roasted or boiled like chestnuts or turned into flour.
Unripe jackfruit is eaten more like a vegetable or meat substitute and is canned in water, brine, or pre-made sauces found at your local grocery store or online. It is commonly used in curries and vegan dishes like pulled ‘pork’ and tacos.
Jackfruit leaf tea made from the leaves is readily available. A tea preparation of jackfruit leaves equivalent to 20 g/kg body weight lowered blood sugar levels in both healthy and diabetic adults [13].
User Experiences
Several users found canned, unripe jackfruit to be a versatile, plant-based substitute for meats due to its chewy and sinewy texture. However, one user found jackfruit as a pulled ‘pork’ substitute lacked the fattiness of the animal meat.
One user was happy not only with the consistency but also with the ease of use of jackfruit flesh. They also loved how fast it took to make a vegan version of pulled pork.
Some users found the flavor of jackfruit to be similar to mushrooms and artichokes.
