Not long ago, a barista at an organic juice bar tried to sell me on the health benefits of a beet and ginger cocktail. “It’s good for the heart,” he said. Although he had all the slickness and charisma of a snake-oil salesman, a recent study by scientists at Howard University suggests there may be some truth to his claims. And that could be especially good news for African Americans.
Blacks suffer disproportionately from high blood pressure, or hypertension, which can lead to strokes, heart attacks, and other cardiovascular diseases. Even in healthy African Americans, strenuous exercise tends to produce spikes in blood pressure that are significantly bigger than those seen in whites. Such spikes can be an early sign that a person is at risk to develop hypertension.
The prevalence of hypertension among blacks may be partly genetic: One of the ways that our bodies regulate blood pressure is by producing nitric oxide—it relaxes the muscles around blood vessels—but evidence suggests that African Americans just don’t produce that much of it.
That’s where the beet comes in. Beets don’t contain nitric oxide but they do contain nitrates, which many scientists think can be processed by our bodies into nitric oxide. Vernon Bond , a professor in Howard’s department of health, human performance and leisure studies, and his collaborators at the Howard College of Medicine set out to test whether a tall glass of beet juice would reduce the exercise-related spikes in blood pressure for a test group of thirteen African American women.
Over the course of about a month, the women came into the lab for three closely monitored workouts. In each workout, they had to pedal a stationary bike against increasing resistance, basically until they couldn’t any more. On the first visit, the subjects didn’t drink anything prior to working out. On the last two visits, they drank either a half liter of orange juice, the placebo, or a half liter of beet juice.
The serving of beet juice increased levels of nitric oxide in the participants’ bloodstream nearly fivefold. That didn’t really affect the their heart rates, but it did significantly lower their blood pressure—both while working out and while resting.
How long does the effect last? Well, the authors don’t say—and presumably a single serving of beet juice can’t be expected to work a lifelong miracle. Plus, there may be downsides to consuming too many nitrates. A dietary supplement’s full spectrum of effects can be hard to disentangle. Still, the Howard study adds to a long list of work suggesting that nitrates may indeed be good for the heart.
As for the beet-juice cocktail, I have to admit I wasn’t too fond of the taste. (I did, however, like the carrot juice concoction that the barista very kindly let me sample.) So I doubt I’ll become a regular consumer of the beetroot. Lucky for me, however, the beet doesn’t have a monopoly on nitrates—they are also found in most leafy green vegetables.