Is graviola (or soursop), which comes from a tropical evergreen tree, a cure for cancer? Today we take a closer look at the online rumors.
Graviola is a tropical evergreen tree which grows in parts of Central America, South America, the Caribbean, Southeast Asia, and West Africa. Apparently the fruit, leaves, and stems of the tree have been used to create various traditional/folk medicines. In recent years, there have been some claims that graviola medicine is a potential cure for cancer which is 10,000 times stronger than chemotherapy.
While we can’t completely dismiss claims that graviola may help fight cancer, it is premature at best to spread unverified information about its effectiveness as a cancer fighter in humans.
Graviola Cancer Claims
The excessive claims in relation to graviola’s cancer-battling properties are being shared on social media. Some of these claims have also been perpetuated by vendors selling graviola extract and people with strong beliefs in alternative medicine.
Below are a list of the major claims in question:
- Graviola effectively destroys multiple types of cancer cells without the negative side effects of chemotherapy
- Graviola is 10,000 times stronger than the chemotherapy drug Adriamycin
- Legitimate science studies have shown evidence that graviola fights cancer
- The evidence that graviola cures cancer is being suppressed
Most of the cancer-fighting discussion originated from Purdue University studies that have shown some positive anti-cancer properties of graviola. While it is true that there have been some studies showing possible cancer-fighting properties, these studies have either been in mice or in test tubes – meaning it hasn’t been tested on human subjects yet. Further, there is evidence of potentially serious side effects.
Addressing Graviola Claims
The information below is a collection of reliable sources which attempt to address the above-mentioned claims attributed to graviola.
10,000 Times Stronger Than Chemo – Thanks to a commenter, we were led to a 1996 science study which is where the claims that Graviola is “10,000 times stronger than chemo” originated. Though the study does in fact use the phrase “10,000 times the potency of adriamycin” this was referring to an isolate known as cis-annonacin – a compound which was isolated from Graviola seeds. These were laboratory experiments, and these compounds were not given to human subjects. Eating graviola fruit – unless you were to eat the seeds – would not provide you with this compound. Also note that it wasn’t reported how much of the compound was used or how much of it exists in a single seed. Additionally, graviola seeds are known to be somewhat toxic.
Other Science Studies – The stories in circulation about graviola mentions that studies were done, but they don’t actually cite or link to any. Below are a few examples of science studies focused on graviola research.
- A 2003 study showing showing graviola can cause Parkinson’s-like symptoms.
- In-Vitro study showing “promise” against pancreatic cancer.
- A breast cancer study, in vitro and in mice, showing some promise.
- 2013 science study in which graviola leaf extract inhibited growth of cancer cells by 80%
American Cancer Society – A brief January 2014 article from the Chicago Tribune responded to a reader question about the ability of soursap or soursop to fight cancer. The article claims that the director of nutrition and physical activity for the American Cancer Society, Colleen Doyle, had written an email which made the following statement:
A few lab studies have been conducted that suggest that extracts of the fruit may kill some types of cancer cells, but at this point in time, there is no evidence from human studies that consuming soursop — or supplements made from it — is beneficial for treating cancer.
FTC and FDA – The Federal Trade Commission (FTC) and the United States Food and Administration (FDA) have both issued statements in regards to graviola.
In September of 2008, the FTC issued a press release entitled “FTC Sweep Stops Peddlers of Bogus Cancer Cures“. The release details the law enforcement action taken against several companies selling false cancer cures. One of these companies, Bioque Technologies, Inc., was fined for claiming that their “soursop” or “guanabana tropical fruit tree” could cure melanoma. Lydia Parnes, Director of the FTC’s Bureau of Consumer Protection, was quoted as saying, “There is no credible scientific evidence that any of the products marketed by these companies can prevent, cure, or treat cancer of any kind.”
Similarly, the FDA forbids companies from making claims that are not backed by solid scientific evidence and selling unapproved drugs. In April of 2014, the FDA publicly posted a letter to a company which sold graviola extract as a cancer cure. The letter can be viewed here. Below is a quote directly from the letter:
Your product is not generally recognized as safe and effective for the above referenced uses and, therefore, the product is a “new drug” under section 201(p) of the Act [21 U.S.C. § 321(p)]. New drugs may not be legally introduced or delivered for introduction into interstate commerce without prior approval from FDA, as described in section 505(a) of the Act [21 U.S.C. § 355(a)]; see also section 301(d) of the Act [21 U.S.C. § 331(d)]. FDA approves a new drug on the basis of scientific data submitted by a drug sponsor to demonstrate that the drug is safe and effective.Furthermore, your product Graviola Extract is offered for conditions that are not amenable to self-diagnosis and treatment by individuals who are not medical practitioners; therefore, adequate directions for use cannot be written so that a layperson can use this drug safely for its intended purposes. Thus, this drug is misbranded within the meaning of section 502(f)(1) of the Act, in that its labeling fails to bear adequate directions for use [21 U.S.C. § 352(f)(1)]. The introduction of a misbranded drug into interstate commerce is a violation of section 301(a) of the Act [21 U.S.C. § 331(a)].
WebMD – This popular conventional medical website appears to have a mixed opinion on graviola. First, it is stated that there is “insufficient evidence” that graviola can be used to fight cancer, yet the following sentence claims, “There is evidence that some of the chemicals in graviola may keep cancer cells from removing anticancer drugs. This may help the drugs work better. Some chemicals in graviola may also kill cancer cells directly.”
The website later, however, describes graviola as an unsafe product in a section on side effects, “Graviola is UNSAFE. It can kill nerve cells in the brain and other parts of the body. It may cause movement disorders similar to Parkinson’s disease.”
Dr. Andrew Weil – Dr. Weil, a champion of integrative medicine, combining alternative and traditional practices, wrote about graviola claims in 2007 . He points out that the Purdue study actually used a substance from a related tree, the annona glabra (AKA Pond Apple), and testing was done in vitro (not on human subjects). At the end of the article, he concludes by saying that he does not recommend taking graviola extract. Below is a quote from his writing:
The idea that graviola is an effective cancer fighter comes from research at Purdue University’s School of Pharmacy and Pharmaceutical Sciences on the active components of the tree, unique substances known as annonaceous acetogenins. The Purdue investigators found them to be potent inhibitors of cancer cells while leaving normal cells alone. They also found the compounds to be effective against drug-resistant cancer cells.
But these were in vitro results – that is, the results of adding the annona derivatives to cancer cells growing in test tubes. This is a long way from clinical trials to determine the safety and efficacy of these compounds in people with cancer. In fact, I have found no human studies at all of graviola, for treatment of cancer or anything else. We do not even have basic safety data on graviola extracts. What’s more, there is no way to tell whether commercially available graviola contains any of the compounds studied at Purdue. Indeed, the compounds used in the test tube studies didn’t come from the custard apple tree at all, but from the leaves of annona glabra, a related tree that grows in Florida and produces a fruit called pond apple.
Cancertutor.com – This website is strictly for alternative cures, and it compares graviola to another of its cousins, Paw Paw (Asimina triloba) in which the following is stated: “Paw Paw is clearly more powerful than graviola when treating cancer… ”
This site does suggest that graviola is accepted by the alternative medical community, but only as a weaker cousin to Paw Paw.
Cancer Research UK – We also looked to a non-US cancer center for info and found similar opinions on graviola. Among their findings about graviola, they state, “We know very little about how graviola affects the body. But we do know it can cause nerve changes, causing symptoms similar to Parkinson’s disease… We do not support the use of graviola to treat cancer.”
We could not find glowing endorsements of graviola from conventional, integrative, or alternative medicine.
Claims of graviola’s anti-cancer claims cannot be completely dismissed, though glowing endorsements are also perhaps premature. Further, despite early anti-cancer findings, there are almost equally disturbing results that graviola may do as much harm as it does good, potentially causing Parkinson’s-like symptoms.
Other Names for Graviola
According to WebMD, graviola is also known by the following names:
Annona cherimola, Annona macrocarpa, Annona muricata, Brazilian Cherimoya, Brazilian Paw Paw, Corossol, Corossol Épineux, Corossolier, Durian Benggala, Guanabana, Guanavana, Nangka Blanda, Nangka Londa, Soursop, Sour Sop, Toge-Banreisi.
Updated January 16, 2015
Originally published September 2012