According to recent study it was discovered that blood pressure decreases if healthy volunteers ingest a natural nitrate source – beetroot juice. Researchers proved that it was the nitrate in the juice that had the result, and it occurred through the nitrate’s chemical drop to nitrite. In a study, 0.5 L of fresh beetroot juice decreased systolic blood pressure as much as 10 mmHg, and blood pressure was still considerably reduced 24 hours later. The researchers found that blood pressure was reduced within just one hour of ingesting beetroot juice, with a peak reduction occurring three to four hours after ingestion. Some degree of reduction continued to be observed up to 24 hours after ingestion.
Researchers proved that the decrease in blood pressure was a result of the chemical formation of nitrite from the dietary nitrate in the juice. The nitrate in the juice is converted in saliva, by bacteria on the tongue, into nitrite. This nitrite-containing saliva is swallowed, and in the acidic medium of the stomach is either converted into nitric oxide or re-enters the circulation as nitrite. The peak time of decrease in blood pressure correlated with the appearance and peak levels of nitrite in the circulation. Several researches also proved that pomegranate juice may have similar effects on blood pressure,though it is still inconclusive.
A reduction in blood pressure was also proved in a study carried in 2006, in healthy volunteers, after three days of dietary supplementation with inorganic nitrate. A year later, it was shown that dietary nitrate reduces whole-body oxygen consumption in humans while doing sub-maximal exercise. This could be due to the vaso-dilatation of the blood vessel walls, resulting less need for oxygen consumption by muscle.