Beetroot juice and measuring blood nitrate from fingertip samples
What it found
After drinking beetroot juice, fingertip blood samples tracked the same changes in nitrate and nitrite as standard arm-vein blood draws.
This was tested in 10 young adults.
What they found
Studies in people
Fingertip versus vein samples
Before the beetroot juice, nitrate and nitrite levels were about the same in fingertip and vein blood. After drinking it, fingertip samples showed higher amounts than vein samples throughout the 4 hours.
Tracking changes over time
Nitrate and nitrite levels in fingertip blood moved closely with those in vein blood across most time points. The link was weaker for nitrate at 2 and 4 hours after the drink.
How much higher fingertip readings were
After the beetroot juice, fingertip nitrate readings were 125–141% of the vein values. Fingertip nitrite readings were 156–183% of the vein values.
What the authors conclude
- They say fingertip blood samples can be used to track nitrate and nitrite levels after taking in dietary nitrate.
- They note that fingertip sampling is practical outside a lab because it needs no special equipment.
- The authors add that nitrate readings from fingertips may be less precise than nitrite readings.
How it was done
Dietary nitrate may support exercise performance by boosting nitric oxide in the body. The authors wanted to know if a simple finger prick could replace a vein blood draw for tracking these levels outside a lab.
Ten healthy young adults drank 140 mL of nitrate-rich beetroot juice. Researchers took blood from a fingertip and an arm vein before the drink and every hour for up to 4 hours after. They then compared the nitrate and nitrite amounts in both types of samples.
What it can’t tell you
- This work only looked at how two blood-sampling methods compare, not at any health effects of beetroot juice itself.
- With just 10 young adults, scientists do not yet know if the results apply to older people or larger groups.
The paper
- Title
- Nitrate and Nitrite Concentrations in Fingertip Serum Following Beetroot Juice Ingestion Correlate with Those in Venous Plasma
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Fujii N, Omori S, Kataoka Y, Nishiyasu T, Omi N (2024). Nitrate and Nitrite Concentrations in Fingertip Serum Following Beetroot Juice Ingestion Correlate with Those in Venous Plasma. Journal of nutritional science and vitaminology. doi:10.3177/jnsv.70.441Free full textPubMed 39477482DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error