The Study
Phenylindanes in Brewed Coffee Inhibit Amyloid-Beta and Tau Aggregation
This study tested coffee chemicals in a test tube to see if they could stop sticky brain proteins from clumping together. It didn’t test coffee in people, so we can’t say drinking coffee helps prevent Alzheimer’s — it just shows a possible lab trick that might one day lead to a medicine.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Scientists tested coffee parts to see which ones stop bad proteins from clumping in the brain — clumps cause Alzheimer’s and Parkinson’s.
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 56 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — if these effects happen in humans, dark roast coffee might help prevent Alzheimer’s, but could risk worsening Parkinson’s in some cases.
- 2Dark roast coffee stops amyloid-beta clumping 4x better than light roast.
- 3Phenylindane (a compound in dark roast) stops 99% of amyloid-beta clumps and 95% of tau clumps.
- 4Caffeine does nothing.
- 5Some other coffee parts make Parkinson’s protein clump more.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Neuroscience
Year
2018
Authors
Ross S. Mancini, Yanfei Wang, D. Weaver
Related Content
Claims (7)
Dark roast coffee has a special compound that might stop two harmful proteins in the brain from clumping together, which could be good for brain health.
When coffee beans are roasted, they make some natural compounds that, in lab tests, stop harmful clumps of brain proteins from forming—clumps that are linked to Alzheimer’s disease. One of these compounds, called phenylindane (6), was super effective at stopping these clumps.
Dark roast coffee seems to stop harmful clumps in the brain better than light roast coffee, and scientists think it’s because the darker roasting creates special compounds called phenylindanes.
In the brain, sticky clumps called beta-amyloid plaques build up over time and interfere with how brain cells talk to each other, which can make it harder to think and remember things.
Even when there’s a lot more caffeine than the sticky proteins in the brain, it doesn’t stop those proteins from clumping together — so caffeine probably isn’t the main reason coffee might help prevent brain clumps.
A compound in coffee called quercetin might stop some harmful protein clumps linked to Alzheimer’s from forming, but it doesn’t stop another type linked to tau, and at high doses, it might even make a different protein clump more — so its effects are mixed and not simple.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.