March 22, 2002 -- Two glasses of orange juice a day lowers blood pressure, a new study suggests. It doesn't mean that OJ is the cure for what ails you. It does mean that a good diet is crucial -- especially for heart patients.
A Cleveland Clinic research team led by Dennis L. Sprecher, MD -- and funded by Tropicana -- tested whether orange juice should be part of this diet. The 25 study patients all had heart disease with partly clogged arteries. All were being treated for high blood pressure with drugs, but it was still too high.
For the first two weeks of the study, they drank two glasses a day of an orange-flavored drink fortified with vitamin C. Their blood pressure dropped a bit. During the next two weeks, they drank plain, not-from-concentrate orange juice. Blood pressure dropped a little more. For the next two weeks they drank OJ fortified with vitamin C and for the two weeks after that they drank OJ fortified with both vitamin C and vitamin E. At the end of the final two weeks, most patients had blood pressure within the normal range.
"The blood-pressure decrease we saw is definitely clinically relevant," says Carla McGill, PhD, RD, a nutrition scientist at Tropicana. "If we could reduce blood pressure by this much it would be very good for all patients."
At the end of the study, the patients stopped drinking orange juice for two weeks. Their blood pressure started to go back up again.
The blood pressure decreases seen in the study were significant. Still, they seem rather small: a decrease of 6.9% in systolic blood pressure (the "top" number that measures pressure when the heart pumps) and a decrease of 3.5% in diastolic blood pressure (the "bottom" number that measures pressure when the heart relaxes).
Would this really matter? Laurence Sperling, MD, director of preventive cardiology at Atlanta's Emory University, says the study is too small to know for sure. But the findings do add weight to overwhelming evidence that a good diet is the most important factor in heart disease.
"This study is intriguing and thought-provoking but it doesn't mean we should tell people to drink two glasses of orange juice a day," Sperling tells WebMD. "But people with heart problems absolutely have to make changes to their diets. There is good data that diet -- weight loss, watching alcohol, and salt intake -- may have a greater impact than medical therapy."
And as the OJ study suggests, a little drop in blood pressure goes a long way.
"A small difference in blood pressure can make a big difference in cardiovascular risk," Sperling says. "And in a diabetic person, we shouldn't be satisfied with just reasonable control -- we should go for optimal blood pressure."-->