Dietary nitrates and circulation

The nitrate pathway, in three steps

1. You eat nitrate-rich vegetables: spinach, arugula, lettuce, beets, celery.
2. Bacteria on your tongue convert nitrate to nitrite. You swallow it.
3. Your body turns nitrite into nitric oxide, which helps blood vessels relax and widen.

This is a backup route to the nitric oxide your vessel lining makes on its own. It matters more as you get older, because the lining tends to make less.

What the long-term evidence shows

A Danish study followed 56,468 people for 23 years. Those who ate the most nitrate-rich vegetables had slightly lower blood pressure and 15% fewer hospital visits for heart and blood vessel disease. The drop for leg artery disease was 26%. The benefit flattened out around one cup of leafy greens a day. See the full article.

The mouthwash problem

If the bacteria on your tongue do step two, killing them could block the pathway. Small lab studies found antibacterial mouthwash raised blood pressure. A larger observational study found people using mouthwash twice a day or more developed high blood pressure more often. See the mouthwash article.

Beet juice: short-term vs. long-term

Many trials show a drop in blood pressure within hours of drinking beetroot juice. Fewer studies show the effect lasting for months. Whole vegetables have the longest track record.

Sources

• Bondonno et al., European Journal of Epidemiology (2021)
• Joshipura et al., Blood Pressure (2020)