Study analysis · Alzheimer's & Dementia : Translational Research & Clinical Interventions · 2025
This common supplement lowered a key Alzheimer's blood marker by 7% in just 8 weeks – but it won't boost your memory.
A vitamin-like supplement called nicotinamide riboside (NR) was safe but didn't improve thinking or memory; however, it reduced a blood marker of Alzheimer's disease (pTau217) and increased daily steps by about 11%.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
In simple terms
This study gave some people a vitamin-like pill (NR) and others a fake pill to see if it helps brain health. They found that the pill did not make people's memory or thinking better, but it did lower a substance in the blood that is linked to Alzheimer's disease. This is promising, but we need more studies to know if the pill actually helps prevent or treat Alzheimer's.
What’s the bottom line?
Researchers tested a supplement called nicotinamide riboside (NR) in older adults with mild memory problems. They gave it for 8 weeks and checked thinking skills and blood markers for Alzheimer's disease.
How strong is this study?
The study was done well because neither the people taking the pills nor the doctors knew who got the real pill, which helps make sure the results are fair. However, the study was small (only 37 people finished) and short (8 weeks), so we can't be sure the findings apply to everyone or last a long time. More research is needed to trust the results completely.
40 / 100
- COI disclosure+40/40
- Data availabilitydata not shared
- Code availabilitycode not shared
80 / 100
- Randomization+20/20
- Blinding+15/15
- Control group+15/15
- Sample size (n=46)+4.1/20
- Follow-up+10/10
100 / 100
77 / 100
- P-values+15/15
- Effect size+20/20
- Confidence intervalsno confidence intervals
- Pre-registration+15/15
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 575 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
This design can establish causation. The study is a randomized controlled trial, which can establish causation. However, the primary cognitive outcome was negative, and the only significant effect was on a secondary biomarker (pTau217). The sample size is small (n=46), and the crossover design may have carryover effects. Therefore, while the study supports a causal effect of NR on pTau217 reduction, the evidence is not definitive and requires replication.
Moderate COI
Moderate conflicts that may influence study outcomes
The study tested nicotinamide riboside (NR) provided by ChromaDex Inc., the manufacturer of TruNiagen. No conflict of interest statement was provided, but the company supplied the intervention.
Funders
Conflict Details
ChromaDex Inc.: Provided the study drug (TruNiagen) and placebo
Independent Analysis Safeguards
- Randomization schedule prepared by independent statistician
- Double-blind design
- Placebo-controlled
- Crossover design allowing within-individual comparisons
No formal conflict of interest or competing interests section was present in the provided text. The only disclosed industry relationship is the provision of the supplement by ChromaDex Inc. No author employment or additional financial ties were mentioned.
Key takeaways
- 01
NR did not improve memory or thinking scores.
- 02
But it lowered a blood marker of Alzheimer's (pTau217) by 7%, while the placebo group saw an 18% increase.
- 03
People taking NR also walked about 11% more steps per day.
- 04
The lack of cognitive change is not surprising for a short study.
- 05
The reduction in the Alzheimer's blood marker is promising but needs confirmation in larger, longer trials.
Surprising findings
- NR did not improve cognitive scores on any test (RBANS, Lumosity) despite lowering pTau217, a key Alzheimer's marker.Most people assume that if a supplement affects Alzheimer's biology, it should also help thinking. This study shows the two can be disconnected in the short term.
- Within the same people, NR increased step counts by 11% while placebo decreased them by 4%.A pill that makes you walk more? This is an unexpected 'side effect' that could have big health implications.
Practical takeaways
If you're over 55 with memory concerns, NR (1g/day) is safe but don't expect a memory boost in the short term. It might help your Alzheimer's biomarker profile.
Small sample (37 completers), short duration, and no long-term data. Not a substitute for exercise, diet, or medical advice.
medium confidenceTrack your step count – the within-study increase suggests NR might boost physical activity. Wear a Fitbit and see if you notice a difference.
Effect was modest and seen only in within-individual analysis, not between groups. Could be due to chance or other factors.
low confidenceWhy this study matters
No Brain Boost, But a Biomarker Win
After 8 weeks of NR (1g/day), cognitive tests (RBANS, Lumosity) showed no improvement compared to placebo. However, plasma pTau217 – a marker of Alzheimer's pathology – dropped 7% in the NR group while rising 18% in the placebo group (p=0.02).
This suggests NR might slow Alzheimer's-related brain changes even if you don't feel sharper. For people worried about dementia, a blood test improvement could be as important as a memory test.
Walk More with NR
Within-individual analysis showed participants took 11% more steps daily while on NR compared to placebo (p=0.04). That's roughly 800 extra steps per day for the average sedentary older adult.
A simple, measurable lifestyle change from a pill. If NR can boost physical activity, it could have ripple effects on overall health.
Safety First?
NR was well-tolerated with no more side effects than placebo. 57 adverse events total, but only 2 related to study procedures (headache from lumbar puncture, Fitbit sore).
Many people fear supplement side effects. This study provides reassurance that short-term use is safe.
Want the whole report?
Detailed mode opens the full scientific breakdown — every score component, the methodology, conflicts of interest, the evidence analysis behind each claim, and the raw study data.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Researchers tested a supplement called nicotinamide riboside (NR) in older adults with mild memory problems. They gave it for 8 weeks and checked thinking skills and blood markers for Alzheimer's disease.
Research results
NR did not improve memory or thinking scores. But it lowered a blood marker of Alzheimer's (pTau217) by 7%, while the placebo group saw an 18% increase. People taking NR also walked about 11% more steps per day.
What this means - more context
The lack of cognitive change is not surprising for a short study. The reduction in the Alzheimer's blood marker is promising but needs confirmation in larger, longer trials.
To test the safety and efficacy of 8 weeks of oral nicotinamide riboside (NR) supplementation (1 g/day) on cognition and plasma Alzheimer's disease biomarkers in older adults with subjective cognitive decline or mild cognitive impairment.
NR was safe and well-tolerated but did not improve cognition as measured by standard or digital assessments. NR reduced plasma phosphorylated tau 217 (pTau217) concentrations compared to placebo (7% decrease versus 18% increase, p=0.02). No significant effects were observed on other biomarkers (GFAP, NfL) or cognitive tests. Within-individual analysis showed a modest increase in step counts with NR.
Methods Used
Double-blind, placebo-controlled randomized crossover trial with a 4-week placebo lead-in followed by two 8-week treatment periods. 46 participants aged 55+ with SCD/MCI were randomized to NR-PBO or PBO-NR sequences; 37 completed. Primary outcome: RBANS total score. Secondary: plasma pTau217, GFAP, NfL. Exploratory: Lumosity gameplay scores and daily step counts from Fitbit.
Main Finding
NR supplementation did not improve cognitive function but reduced plasma pTau217 levels, a biomarker of Alzheimer's pathology, compared to placebo (Cohen's d=0.8, p=0.02).
Confidence Level
Moderate; small sample size and short duration, but rigorous double-blind crossover design with consistent findings across analyses.
Study Flags
Red Flags
- •Small sample size (37 completers)
- •Short duration (8 weeks)
- •Crossover design may have carryover effects
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Surprising Findings
NR did not improve cognitive scores on any test (RBANS, Lumosity) despite lowering pTau217, a key Alzheimer's marker.
Most people assume that if a supplement affects Alzheimer's biology, it should also help thinking. This study shows the two can be disconnected in the short term.
Practical Takeaways
If you're over 55 with memory concerns, NR (1g/day) is safe but don't expect a memory boost in the short term. It might help your Alzheimer's biomarker profile.
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 575 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Human RCT
Subject
High probability
on the GRADE evidence scale
This study gave some people a vitamin-like pill (NR) and others a fake pill to see if it helps brain health. They found that the pill did not make people's memory or thinking better, but it did lower a substance in the blood that is linked to Alzheimer's disease. This is promising, but we need more studies to know if the pill actually helps prevent or treat Alzheimer's.
Moderate conflicts detected — such as industry funding with partial involvement. A meaningful penalty has been applied.
Strengths
- Randomized, double-blind, placebo-controlled design.
- Crossover design with within-subject comparisons increases power.
- Multi-modal assessments including cognitive tests, digital gameplay, wearables, and plasma biomarkers.
Weaknesses
- Small sample size (n=46 randomized, 37 completed).
- Primary cognitive outcome (RBANS) did not show significant benefit.
- Significant finding on secondary biomarker (pTau217) may be due to chance given multiple comparisons.
Methodology
Evidence Keywords
Statistical Reporting
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Researchers tested a supplement called nicotinamide riboside (NR) in older adults with mild memory problems. They gave it for 8 weeks and checked thinking skills and blood markers for Alzheimer's disease.
Research results
NR did not improve memory or thinking scores. But it lowered a blood marker of Alzheimer's (pTau217) by 7%, while the placebo group saw an 18% increase. People taking NR also walked about 11% more steps per day.
What this means - more context
The lack of cognitive change is not surprising for a short study. The reduction in the Alzheimer's blood marker is promising but needs confirmation in larger, longer trials.
To test the safety and efficacy of 8 weeks of oral nicotinamide riboside (NR) supplementation (1 g/day) on cognition and plasma Alzheimer's disease biomarkers in older adults with subjective cognitive decline or mild cognitive impairment.
NR was safe and well-tolerated but did not improve cognition as measured by standard or digital assessments. NR reduced plasma phosphorylated tau 217 (pTau217) concentrations compared to placebo (7% decrease versus 18% increase, p=0.02). No significant effects were observed on other biomarkers (GFAP, NfL) or cognitive tests. Within-individual analysis showed a modest increase in step counts with NR.
Methods Used
Double-blind, placebo-controlled randomized crossover trial with a 4-week placebo lead-in followed by two 8-week treatment periods. 46 participants aged 55+ with SCD/MCI were randomized to NR-PBO or PBO-NR sequences; 37 completed. Primary outcome: RBANS total score. Secondary: plasma pTau217, GFAP, NfL. Exploratory: Lumosity gameplay scores and daily step counts from Fitbit.
Main Finding
NR supplementation did not improve cognitive function but reduced plasma pTau217 levels, a biomarker of Alzheimer's pathology, compared to placebo (Cohen's d=0.8, p=0.02).
Confidence Level
Moderate; small sample size and short duration, but rigorous double-blind crossover design with consistent findings across analyses.
Study Flags
Red Flags
- •Small sample size (37 completers)
- •Short duration (8 weeks)
- •Crossover design may have carryover effects
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Surprising Findings
NR did not improve cognitive scores on any test (RBANS, Lumosity) despite lowering pTau217, a key Alzheimer's marker.
Most people assume that if a supplement affects Alzheimer's biology, it should also help thinking. This study shows the two can be disconnected in the short term.
Practical Takeaways
If you're over 55 with memory concerns, NR (1g/day) is safe but don't expect a memory boost in the short term. It might help your Alzheimer's biomarker profile.
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 575 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Human RCT
Subject
High probability
on the GRADE evidence scale
This study gave some people a vitamin-like pill (NR) and others a fake pill to see if it helps brain health. They found that the pill did not make people's memory or thinking better, but it did lower a substance in the blood that is linked to Alzheimer's disease. This is promising, but we need more studies to know if the pill actually helps prevent or treat Alzheimer's.
Moderate conflicts detected — such as industry funding with partial involvement. A meaningful penalty has been applied.
Strengths
- Randomized, double-blind, placebo-controlled design.
- Crossover design with within-subject comparisons increases power.
- Multi-modal assessments including cognitive tests, digital gameplay, wearables, and plasma biomarkers.
Weaknesses
- Small sample size (n=46 randomized, 37 completed).
- Primary cognitive outcome (RBANS) did not show significant benefit.
- Significant finding on secondary biomarker (pTau217) may be due to chance given multiple comparisons.
Methodology
Evidence Keywords
Statistical Reporting
Scoring
How strong is this study?
The study was done well because neither the people taking the pills nor the doctors knew who got the real pill, which helps make sure the results are fair. However, the study was small (only 37 people finished) and short (8 weeks), so we can't be sure the findings apply to everyone or last a long time. More research is needed to trust the results completely.
40 / 100
- COI disclosure+40/40
- Data availabilitydata not shared
- Code availabilitycode not shared
80 / 100
- Randomization+20/20
- Blinding+15/15
- Control group+15/15
- Sample size (n=46)+4.1/20
- Follow-up+10/10
100 / 100
77 / 100
- P-values+15/15
- Effect size+20/20
- Confidence intervalsno confidence intervals
- Pre-registration+15/15
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 575 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
This design can establish causation. The study is a randomized controlled trial, which can establish causation. However, the primary cognitive outcome was negative, and the only significant effect was on a secondary biomarker (pTau217). The sample size is small (n=46), and the crossover design may have carryover effects. Therefore, while the study supports a causal effect of NR on pTau217 reduction, the evidence is not definitive and requires replication.
Moderate COI
Moderate conflicts that may influence study outcomes
The study tested nicotinamide riboside (NR) provided by ChromaDex Inc., the manufacturer of TruNiagen. No conflict of interest statement was provided, but the company supplied the intervention.
Funders
Conflict Details
ChromaDex Inc.: Provided the study drug (TruNiagen) and placebo
Independent Analysis Safeguards
- Randomization schedule prepared by independent statistician
- Double-blind design
- Placebo-controlled
- Crossover design allowing within-individual comparisons
No formal conflict of interest or competing interests section was present in the provided text. The only disclosed industry relationship is the provision of the supplement by ChromaDex Inc. No author employment or additional financial ties were mentioned.