Guyabano—a ‘miracle fruit’?
Every now and then, patients with all sorts of imaginable medical problems ask me if commercially prepared guyabano (soursop fruit) products can help cure them.
Usually promoted through direct marketing, guyabano extracts in capsules, juices and tea preparations are claimed to have protective effects from all sorts of cancers. One product brochure that a patient showed me said guyabano extract is supposed to be “a miraculous natural cancer cell killer 10,000 times stronger than standard chemotherapy.”
The direct marketers claim that the products are also good for diabetes, cholesterol problems, Alzheimer’s disease, infertility, impotence, asthma, arthritis, liver and kidney diseases. This also reportedly lowers blood pressure, strengthens the immune system, improves energy levels, heals wounds, eliminates worms, relieves diarrhea and fever, and treats gonorrhea and herpes.
My wife and I love fresh guyabano and we eat a slice of the fruit once or twice a week. We’re sure it is a rich source of antioxidants and enzymes just like many of our local fruits, but expecting it to be a cure-all is simply too much. Any medicinal product which is promoted to be a cure for every ailment known to man is just too good to be true. And in all probability, it’s not true. Someone is just out there to make a fast buck at our expense.
The guyabano capsules, juices and teas are apparently also more expensive than eating the fresh fruit. I would rather enjoy the succulent taste of a freshly sliced guyabano fruit than pop any commercial pills supposed to have the fruit extract.
I reviewed the scientific literatures recently to see if there are any new research findings demonstrating the anticancer and other health benefits of guyabano in humans. The same old data showing some potential benefits in experimental or animal models are all that I could find.
So from the medical or scientific standpoint, that’s how it stands for now. There is some suggestion that the fruit extract might have the property to inhibit the growth of some cancer cells, but this has only been shown in the laboratory—or at most, in experimental animals—but never in humans. It’s a long way from being declared an anticancer fruit with truly clinically meaningful effects. Testimonials from celebrities or even anecdotal reports from doctors of their patients who were supposed to be cured by guyabano extracts don’t really count.
The danger is when some believe these testimonials saying that guyabano is all they need to be cured and discontinue taking standard medicines prescribed by their physicians. One stands the risk of suffering from the worsening of his/her illness without the benefit of treatments which have been tried and tested in humans.
I would not mind so much if the prescribed medicines are taken together with the guyabano supplements. If one has sufficient finances, I don’t see a problem with taking both. But if one has average means, it’s better to prioritize the medicines that have been prescribed rather than the guyabano supplement. But like I said, incorporating fresh guyabano and other nutritious fruits in one’s regular diet is highly recommended.
Having said that, let me quickly add that the potential anticancer benefits of guyabano are promising and I could only wish there would be well-designed studies that our researchers could undertake to show its real benefits in humans. The experimental studies actually started in 1976 yet when the National Cancer Institute in the United States conducted the first study on the fruit’s supposed cancer-fighting properties.
This was followed by 20 more tests conducted in various laboratories worldwide. They all came out with unanimous results: Guyabano tree extracts, indeed, proved to be effective against the growth of malignant cells in 12 cancer types including some of the deadliest cancer forms which have taken the lives of many around the globe, like pancreatic, colon, lung, prostate and breast cancers.
According to the Catholic University of South Korea and Purdue University in Indiana, United States, guyabano tree extracts acted in a way that prevented them from harming normal cells, while successfully targeting the dangerous ones, unlike chemotherapy, which destroys all cells that multiply.
But, it has to be emphasized that all of these trials were conducted in the laboratory only using nonliving models, or what is called as in vitro experiments. Absolutely no research in humans, so far.
So my previous advice stays. One should not rely too much on marketed guyabano products to take care of whatever medical problems one has, especially if it’s cancer. But that advice should not prevent us from enjoying the fresh fruit.
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