Daily orange juice could lower diastolic blood pressure

Drinking orange juice every day may have important heart health benefits.  A recent study published online in the American Journal of Clinical Nutrition found that consuming about two cups of 100 percent orange juice every day for one month significantly lowered diastolic blood pressure among men who were slightly overweight, but otherwise healthy.(1) Improvements also were seen in other indicators of cardiovascular health, notably better functioning of the inner lining of blood vessels.

These results were observed when men drank 100 percent orange juice, as well as when they consumed a control drink plus purified hesperidin. Hesperidin, which is naturally found in oranges and orange juice, is a plant flavonoid, a member of the polyphenol family of plant compounds, which may have beneficial effects on human health.

"The main result of this study is that orange juice and hesperidin appear to promote a decrease in blood pressure, particularly diastolic blood pressure. This likely is the result of improved blood flow induced by a better functioning of the blood vessels. At the anatomical level, these beneficial effects on blood circulation could be due to a positive effect of orange juice and hesperidin on blood vessel dilatation and vessel resistance," said Christine Morand, lead author of the study from the French National Institute for Agronomic Research. "While the benefits were seen with both orange juice and hesperidin, results were most significant for orange juice, indicating that other properties in orange juice may be playing additional beneficial roles."

Study Highlights

In this randomized, controlled, cross-over study, 24 healthy overweight men, aged 50 to 65 years, consumed three different four-week dietary treatments, with a three-week 'wash-out' period between each treatment:

1. 500 milliliters a day of 100 percent orange juice, which is equivalent to 17 ounces or about 2 cups of orange juice;
2. 500 milliliters a day of a control drink plus a capsule of 292 milligrams of hesperidin, which was equivalent to the amount naturally found in the 500 milliliters of orange juice provided and;
3. 500 milliliters a day of a control drink plus a placebo.

Significant benefits seen from both the consumption of 100 percent orange juice and the purified hesperidin include:

• Improvements in blood pressure: Diastolic blood pressure (DBP), the bottom number in a blood pressure reading, significantly decreased by an average of 5.5 mmHg when the 100 percent orange juice group was compared to the placebo control group and by an average of 3.2 mmHg when the hesperidin group was compared to the placebo control group.  DBP is the pressure on artery walls when the heart relaxes between beats. DBP values are an important cardiovascular health indicator: the higher the diastolic blood pressure, the greater the risk for heart attacks, strokes and kidney failure.
• Improvements in blood vessel function: The inner lining of blood vessels demonstrated a significantly better ability to widen (called "vasodilation") immediately following both the orange juice and hesperidin treatments, with orange juice having a more significant effect. When blood vessels widen, there is less resistance to blood flow which leads to a decrease in blood pressure. This reduces the heart's workload, and serves as an important indicator of overall cardiovascular health.

Heart Health Benefits of 100 Percent Orange Juice

This study supports a larger body of epidemiologic evidence that has shown citrus fruit consumption is associated with a number of cardiovascular benefits including a lower risk of acute coronary events and stroke. (2),(3)

 Note: The research was supported by a grant from the Florida Department of Citrus (FDOC). FDOC's role was limited to the provision of orange juice and the analysis of orange juice components. FDOC had no role in study design, data collection, data analysis, decision to publish or preparation of the manuscript.