Updated: Jan 11, 2020
I went on a cruise to the Bahamas last Thanksgiving and did a tour of the beautiful city of Nassau. Our first stop was at a local tea shop where we were briefed before going in on the types of teas they carried along with their associated health benefits. One tea called “soursop,” whose benefits ranged from hypertension to cancer prevention and treatment. I bought the package and came home and started drinking it. It’s a bland tea whose name can be misleading as it is not sour at all. This tea was made from the leaves of the Annona muricata tree which produces soursop, is a tropical fruit grown in African, Caribbean, Southeast Asian, and Latin American countries.
When I got home, I found a study in the Journal of Human Hypertension showing that adults in Indonesia with elevated blood pressure or stage 1 hypertension were able to lower their blood pressure significantly by eating 100 grams of soursop fruit twice a day for 3 months. The study included 143 adults randomly assigned to soursop consumption or to a nontreatment control and proper measures were implemented to ensure the results were valid and reproducible like taking all measurements in the mornings and “blinding” the researchers to the participants’ study group assignment.
Blood pressure decreased more in the group that ate the soursop fruit twice per day than in the control group with systolic (the higher number) decreasing from 134 to 118 and diastolic decreasing from 85 to 73. Not only were these results statistically significant, but also clinically relevant as a decrease in systolic blood pressure of just 2 can decrease the risk heart disease and death from all causes according to the INTERSALT study. In fact, many participants who started the study with elevated blood pressure had normal blood pressure by the end of the 3 months.
Hypertension can result from high-salt diets, stress and people with a family history of high blood pressure are at higher risk. Hypertension can wreak havoc on the human body and like many other conditions, most people with hypertension don't have symptoms. This must make it difficult for healthcare workers and public health professionals to convince people of the dangers of this disease. In most people with hypertension, their daily lives aren't being affected by it until a catastrophic event takes place like a stroke. This could be reflected by the fact that 31 of the 143 study participants dropped out before the end of the 12 weeks.
Hypertension increases the risk of stroke, heart attack, kidney disease, aneurysm, heart disease and death and tends to be more prevalent among black and Latin American than white men and women. It is the leading risk factor for heart disease and over 100 million adults in the U.S. alone are affected. Hypertension subjects the blood vessel walls to high forces which over time can damage their inner lining decreasing the ability of this protective layer to slow or prevent plaque buildup. Over the course of years and decades, this leads to an accelerated buildup of plaque which can result in sometimes fatal heart attacks.
This information might sound scary but take comfort in the fact that most cases of hypertension are lifestyle-related and thus, preventable. Optimal blood pressure is less than 120 for systolic and less than 80 for diastolic which might be surprising as 120/80 is often thought of as ideal.
According to the American College of Cardiology and the American Heart Association, blood pressure is elevated if the systolic is between 120 and 129 and hypertension starts at a systolic of 130 and a diastolic of 80. Thus, 120/80, although years ago would have been ideal, is now considered “hypertensive.” These new threshold values were published in 2017 and have not been adopted outside the U.S. as other countries still consider at least 140/90 to be hypertensive.
Soursop could be effective in preventing or treating hypertension but may be hard to find if you don't live in a tropical environment. If you can’t find the fruit, soursop tea could be a good alternative as soursop leaf extract also reduced blood pressure in animal studies. Other ways of lowering blood pressure include reducing the stress in your life, exercising regularly, practicing yoga, and reducing your sodium and increasing your potassium intake.
A few study points for your consideration:
1. Participants in the study were at risk for or in the early stages of hypertension and didn't have blood pressure high enough to be prescribed medications. Those with hypertension, particularly those who've had the disease for years or decades may need to use this supplement longer than 12 weeks in order to see results.
2. Study authors didn't make it clear whether participant's diets and exercise habits were maintained throughout the study. This is important because decreasing sodium intake or exercising at a moderate intensity can lower blood pressure.