It has long been known that compounds known as nitrates have
a beneficial effect for the cardiovascular system.  The most common example of this is
nitroglycerin, a drug that is used for angina (chest pain due to spasm of blood
vessels).  Nitrates are transformed by
bacteria in the mouth to nitrites, which are then converted in the blood into
nitric oxide (NO).  NO relaxes blood
vessels, which can lower blood pressure.

In addition to pharmaceutical nitrates, attention has been
focused recently on whole foods sources of nitrates.  Two studies took a look at the effects of
beetroot juice on blood pressure.  In
2012, Australian researchers (1) found that consuming beetroot juice
significantly lowered systolic blood pressure for up to 6 hours, compared to
placebo.  Beets are a good source of
nitrates, which the body can convert into NO.

But 500 g of beetroot juice is quite a bit.  Some clever Brits (2) therefore compared drinking
liquid beetroot juice to consuming a special beetroot enriched bread.  They found that both were equally effective
in lowering blood pressure, and the bread may be more palatable.  Furthermore, in their study, they noticed that the blood pressure lowering benefits persisted for 24 hours.

One caveat to keep in mind is that both of these studies
were performed with healthy subjects. 
However, eating more vegetables is definitely good for your health anyway,
so increasing your beet intake is a good idea if you’re trying to lower your
blood pressure.  You can also look at
other vegetables that are high in nitrates, such as radishes, carrots, and
lettuce.  And don’t forget the blood pressure lowering benefits of chocolate for dessert!