Two weeks of concentrated beet juice measurably lowered blood pressure in adults in their 60s and 70s, but produced no comparable effect in adults under 30, a double-blind crossover trial from the University of Exeter reports. The finding pushes back on the popular idea that beet juice is a universal blood pressure remedy.
The trial, published in Free Radical Biology and Medicine, enrolled 75 adults split into two groups, 39 people under 30 and 36 people in their 60s and 70s. In one phase, participants drank two 70 ml shots of nitrate-rich beetroot juice every day for two weeks. In the other, they took an identical shot with the nitrate removed. A two-week washout separated the two phases.
Only the older group saw pressure fall. A summary of the results at News-Medical.net puts the mean arterial pressure drop at about 4 mmHg after the nitrate-rich juice, with each daily dose delivering roughly 595 mg of nitrate. Younger participants showed no meaningful change on either drink.
Why age changes the response
Beet juice does not lower blood pressure on its own. The body has to convert dietary nitrate into nitric oxide, a signaling molecule that relaxes blood vessels. Bacteria on the tongue do the first step of that conversion, turning nitrate into nitrite. Nitrite then becomes nitric oxide further down the pathway.
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That pathway matters more with age. The body's own production of nitric oxide falls in older adults, which is one reason blood pressure tends to climb across the decades. Topping up the diet with nitrate appears to help most where the natural supply is running short.
"Older people produce less of their own nitric oxide as they age. They also tend to have higher blood pressure, which can be linked to cardiovascular complications like heart attack and stroke," said Professor Anni Vanhatalo of the University of Exeter, who led the study.
What happened in the mouth
Both age groups showed shifts in their oral microbiome after two weeks of nitrate-rich juice, but the pattern differed. In the older group, the researchers reported a drop in Prevotella bacteria and a rise in Neisseria, a genus involved in converting nitrate to nitrite. Younger participants saw different microbiome changes without the blood pressure benefit.
"This study shows that nitrate-rich foods alter the oral microbiome in a way that could result in less inflammation, as well as a lowering of blood pressure in older people," said Professor Andy Jones of the University of Exeter.
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What it means in practice
The result does not turn beet juice into a treatment. It was a small, short trial in generally healthy adults, and the drop of about 4 mmHg is modest compared with what blood pressure medication can achieve. It does, however, help explain why some people notice nothing when they try beet juice while others see a response.
High blood pressure remains one of the most common health conditions in the United States, and prevalence rises steeply with age, according to the Centers for Disease Control and Prevention. Anyone considering dietary changes to manage blood pressure, and especially anyone already taking medication for it, should talk to a doctor before making a habit of daily nitrate shots. Beet juice is not a substitute for treatment or regular monitoring.
The Exeter work was funded by a BBSRC Industrial Partnership Award, with support from the NIHR Exeter Clinical Research Facility.
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