There is renewed interest in a little-known green, fleshy fruit native to South and Central America that has long been used in traditional medicine to prevent bacterial infections and even prevent and treat many types of cancer. But what exactly is it?
Annonamuricata is a flowering tree native to Central and South America but can now be found in the Pacific Islands, West Africa, and Southeast Asia. It goes by many names, but the most famous is probably soursop, and it's often taken in supplement form. Practitioners of traditional medicine have used the prickly green fruit, bark and leaves for hundreds of years to treat a variety of ailments, from managing diabetes to treating infections and cancer.
But in the last year, there has been renewed interest in the plant—and especially its fruit—particularly from the Western health community, which seeks alternative medicines rooted in traditional healing practices. However, the scientific community remains divided on its benefits. One thing most experts agree on is that more research is needed.
"Of all previous studies on this plant, the most promising activities were its anticancer, antiparasitic and insecticidal activities," the researchers noted in a 2015 review paper published in the International Journal of Molecular Sciences. "Further investigation into the biochemical and physiological functions of active compounds and the detailed mechanisms behind these activities is critical for the development of pharmaceuticals and agricultural products."
Soursop in particular contains bioactive compounds—acetyl coenzymes, alkaloids, flavonoids, and vitamins—that are often viewed as beneficial, particularly because of their cytotoxic effects, or how they kill cancer cells. These acetyl-coenzymes are not only associated with stopping cancer growth, but also with cancer prevention. However, a key acetyl coenzyme, antonin, has also been linked to Parkinson's disease and neurodegenerative diseases.
In 2012, researchers discovered that “the main bioactive compound found in soursop is classified as acetyl-coenzyme from the Annonaceae family, which inhibits mitochondrial complex I, leading to reduced ATP production. Overall, the compounds naturally occurring in soursop extract Inhibition of multiple signaling pathways regulating pancreatic cell metabolism, cell cycle, survival and metastatic properties. Overall, alterations in these parameters resulted in reduced tumorigenicity and metastasis of orthotopically implanted pancreatic tumors, indicating that this natural product has favorable properties against this fatal disease."
Plant biologists will recognize "Annonaceae" as referring to the Annonaceae family, which also includes more common fruit trees such as Annonareticulata. The two species share some characteristics, such as the fruit's milky white flesh and unattractive appearance, but have very different nutritional profiles. One cup of soursop fruit contains 148 calories, 7.42 grams of fiber, 37.8 grams of carbohydrates, and 30.5 grams of sugar, despite its low glycemic index. This fruit is rich in vitamin C, potassium, magnesium as well as antioxidants and potassium. Despite its appearance, soursop actually tastes pretty good, somewhere between strawberry and banana.
While it has been used as an adjuvant treatment for cancer patients for some time, there is currently insufficient scientific data to draw clinical conclusions. Another 2024 review paper found that existing research suggests there's a reason soursop has long been part of traditional medicine.
The researchers noted: "This systematic review found that soursop extract has beneficial effects on cancer, exhibiting cytotoxic effects through inhibition, apoptosis and selective killing of cancer cells without affecting normal cells. In addition, it also has anti-inflammatory effects by activating anti-inflammatory pathways through the prostaglandin synthesis pathway."
In addition to its potential antimicrobial, antioxidant, and anti-inflammatory effects, it has been identified as a neurotoxin that may contribute to neurological disorders. So far, researchers believe this is the result of overconsumption.
"High doses of acetyl-CoA may be neurotoxic and may lead to neurodegenerative diseases," scientists noted in a 2022 study published in the journal Molecules. "Some of the alkaloids present in soursop are thought to also affect nerve cells. However, studies on the neurotoxicity of soursop have shown that neurodegenerative diseases caused by these compounds occur as a result of continued exposure or consumption. Further studies on their toxicity and clinical trials testing pure compounds are needed to fully elucidate their pharmacological activities and ensure the safety of soursop as a potential drug for various diseases."
Although it has been touted as preventing or "curing" cancer, there is little strong scientific evidence to date to support these claims. Still, it's a healthy addition to a salad or smoothie—that is, if you can find this exotic fruit.