A glass or two of orange juice daily could do wonders for our blood pressure, according to a pilot study conducted at the Cleveland Clinic in the United States.
Presenting the findings at the annual Scientific Session of the American College of Cardiology in Atlanta this week, Dennis Sprecher from the Cleveland Clinic claimed that the JUICE (Juice Utilisation Improves Cardiovascular Endpoints) study is the first research to indicate that an everyday food or beverage can lower blood pressure.
"Previous studies have suggested that many of the nutrients found naturally in orange juice, such as potassium, vitamin C and other antioxidants have a beneficial effect on blood pressure,'' said Dr Sprecher. "The next logical step was to find out whether orange juice itself could provide a measurable improvement.''
In this study, Dr Sprecher tested four different beverages, including three 100 per cent orange juices, for two weeks each. There were 24 subjects who had partial blockage in the arteries leading to their heart but whose hypertension and serum cholesterol were then under control. The beverages tested were a vitamin C-fortified juice drink, a not-from-concentrate orange juice,a not-from-concentrate orange juice fortified with vitamin C; and a not-from-concentrate orange juice fortified with vitamins C and E.
During the trial period, all medications were discontinued immediately before each clinic visit. Patients drank two glasses (16 ounces) of the test beverage daily. At the end of each two-week period, measurements were taken of blood pressure and "brachial artery reactivity'' or BART, an indicator of vessel flexibility.
"After adjusting for age, gender and baseline blood pressure, we found that orange juice produced on average about a 10mm/Hg or 7 per cent reduction in systolic blood pressure and about a 3.5 mm/Hg or 4.6 per cent reduction in diastolic blood pressure,'' Dr Sprecher said. None of the patients in the study gained weight.
The researchers concluded that "orange juice appears to positively influence vascular regulation and may have implications for public health strategies toward blood pressure control.''
Hypertension is the most common cardiovascular problem in the United States and is a major risk factor for coronary artery disease.
Although the causes of hypertension are unknown in 95 per cent of cases, diet and lifestyle factors are known to play a key role. Factors that have been found to reduce risk include maintaining a healthy weight, having a physically active lifestyle and following a diet high in fruits and vegetables, whole grains, lean meats and fish, legumes, seeds and nuts.
"The findings from this pilot study are consistent with the results of research on the impact of the DASH programme,'' Dr Sprecher said. DASH stands for Dietary Approaches to Stop Hypertension and is a programme that was clinically proven to lower systolic blood pressure.
"As a next step, we plan to repeat our experiment in a larger number of people,'' Dr Sprecher said. "The potential public health impact could be very exciting,'' he concluded.