Dr. Christopher Winter Medical Director and neurology specialist at Martha Jefferson Hospital Sleep Medicine Center, asks, “Is soursop the Caribbean secret for perfect sleep?” He says that many Caribbean people claim to get a good night’s sleep with soursop. [My grandmother swore it—guanábana—worked, so it must.] Here are excerpts:

Soursop — what’s soursop? It turns out that soursop (Annona muricata) is a fruit mainly grown in tropical climates. It has many other names, including guanábana, graviola, anona, and sirsak. As a member of the Annona genus of flowering plants, its most recognizable relative for Americans is the pawpaw. Soursop is a strange-looking fruit; imagine a Granny Smith apple crossed with a pineapple… on steroids. This should give you a mental image of the spiky fruit, which can weigh up to 15 pounds. Cutting open the green rind reveals a white pulp with a consistency similar to that of cooked fish, and rows of dark, inedible seeds.

[. . .] In the West Indies, soursop leaves are commonly used as a sedative. In the Netherlands Antilles, the leaves are brewed to make a beverage that enhances sleep. The leaves can also be put into one’s pillowcase to enhance sleep. While anecdotal material about soursop as a sleep aid is easy to find, scientific studies are not. [. . .]  While researching soursop’s soporific properties, the aforementioned seeds of the plant kept popping up because of a unique chemical they contain called annonacin.[. . .] While I was unsuccessful finding a connection between annonacin and sleep, I was shocked to find another significant connection. On the Caribbean island of Guadeloupe, within the French West Indies, there is a rare form of Parkinson’s disease that is seen with an unusually high frequency. A body of articles link soursop consumption to this atypical form of Parkinson’s disease that does not respond well to medical treatment. [. . .]

Amazingly, the soursop intrigue did not end there. While there were articles looking at soursop as a treatment of herpes and other lesser disease states, it was the soursop/cancer link that really put this fruit over the top.[12] Numerous in vivo studies seemed to show at least some promise in terms of annonacin being a potential anticancer agent. [. . .] As a physician and researcher, I consider myself fairly evidence-based in my approach to sleep. However, I also subscribe to the philosophy of if it works and it is not harmful, go for it. I wanted to see for myself if soursop was the cure for sleeplessness that many though it might be. It was time to try some soursop.

It turns out, soursop is not so easy to acquire. [. . .] Elsewhere would eventually be St. Thomas in the U.S. Virgin Islands. Arriving in the capital city of Charlotte Amalie, I could not wait to get my hands on soursop. As my skill at driving on the other side of the road improved, I began to find soursop sources throughout the island. Having scoured St. Thomas, I eventually took my red Hyundai to St. John, where I found the best soursop of my trip. On the corner across from the post office in Cruz Bay was a colorful shack with the sign Market Smoothie on top and a chalkboard proclaiming “fresh Soursop.” Paydirt!

Thomas, the friendly “drink specialist,” was happy to show me a genuine soursop fruit (or guanábana). He then produced a knife and swiftly cut out the heart of the fruit, removed its seeds, and blended chunks of the fruit with lemon and lime juice to produce a cold, tart, but tasty beverage on a very hot day. As I stretched out in the shade looking over Hawksnest Bay, I have to admit I felt pretty relaxed. Could it be the soursop? I would say my study was inconclusive, but if I ever come across some funding, this would be a study I would be happy to oversee!

For full article, see http://www.huffingtonpost.com/dr-christopher-winter/soursop-sleep_b_2674521.html