The Study
Effects of inorganic nitrate and nitrite consumption on cognitive function and cerebral blood flow: A systematic review and meta-analysis of randomized clinical trials
This study looked at lots of small experiments where people took beetroot juice or nitrate pills to see if it helped their brain. It found that, overall, it didn’t help. But because each experiment was tiny and didn’t last long, we can’t say for sure if it might help in bigger or longer studies.
Analysis score
Maximum 100 for a systematic review with meta-analysis.
Where the score came from
Scientists looked at 13 studies where people took beetroot juice or nitrate pills to see if it helped their brain work better or increased blood flow to the brain.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 555 / 100
Quality score
The highest quality evidence. Systematic reviews and meta-analyses that pool randomized controlled trials, giving the most reliable summary of experimental evidence.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The changes seen were tiny and not meaningful — like flipping a coin and getting one more head than tails.
- 2It doesn't help your brain work better in real life.
- 313 studies with 297 people: no improvement in thinking skills.
- 49 studies with 163 people: no increase in brain blood flow, even during mental tasks.
- 5Longer use (over days) showed even less effect.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Critical Reviews in Food Science and Nutrition
Year
2018
Authors
Tom Clifford, Abrar M Babateen, O. Shannon, Tess E. Capper, A. Ashor, B. Stephan, L. Robinson, J. O’Hara, J. Mathers, E. Stevenson, M. Siervo
Related Content
Claims (6)
Taking inorganic nitrate supplements does not change cognitive performance or blood flow in the brain in healthy adults.
Longer use of inorganic nitrate or nitrite supplements is linked to smaller changes in blood flow to the brain.
Supplementing with inorganic nitrate or nitrite does not improve cognitive function or cerebral blood flow in healthy young adults, based on studies that only included healthy individuals under age 36.
Taking inorganic nitrate or nitrite supplements does not change blood flow in the brain at rest or during activity in adults.
Current studies on inorganic nitrate or nitrite supplements for brain function and blood flow in the brain are too small and too short to reliably detect small but important changes.
Taking inorganic nitrate or nitrite supplements does not change cognitive performance in adults between 18 and 73 years old.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.