The Study
Associations Between Different Coffee Types, Neurodegenerative Diseases, and Related Mortality: Findings from a Large Prospective Cohort Study.
This study found that people who drank more unsweetened coffee tended to get dementia or Parkinson’s less often, but it didn’t prove that the coffee caused the protection. It just noticed a pattern, like how people who wear helmets might also be more careful in general.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
People who drank 3 or more cups of black coffee every day were less likely to get Alzheimer’s or Parkinson’s disease than those who didn’t drink coffee or drank sweetened versions.
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 559 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — for someone who drinks 3+ cups of black coffee daily, this could mean a meaningful reduction in their chance of developing these brain diseases over time.
- 2People who drank ≥3 cups of unsweetened caffeinated coffee daily had a 25% lower risk of Alzheimer’s and a 29% lower risk of Parkinson’s.
- 3Sweetened, decaf, or less than 2 cups showed no benefit.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The American journal of clinical nutrition
Year
2024
Authors
Tingjing Zhang, Jiangen Song, Zhenfei Shen, Kewan Yin, Feifei Yang, Honghao Yang, Zheng Ma, Liangkai Chen, Yanhui Lu, Yang Xia
Related Content
Claims (6)
Drinking coffee with added sugar or artificial sweeteners does not lower the risk of Alzheimer’s disease, Parkinson’s disease, or death from neurodegenerative conditions.
People who drink at least three cups of unsweetened caffeinated coffee per day have a 25% lower risk of developing Alzheimer’s disease and related dementias and a 29% lower risk of developing Parkinson’s disease compared to those who drink less.
People who drink decaffeinated coffee do not have a lower risk of Alzheimer’s disease, Parkinson’s disease, or death from neurodegenerative causes compared to those who do not drink it, suggesting that caffeine in regular coffee may be responsible for any protective effects.
People who drink at least three cups of unsweetened caffeinated coffee per day have a lower risk of neurodegenerative diseases compared to those who drink less.
People who drink at least three cups of unsweetened caffeinated coffee per day have a slightly lower rate of death from neurodegenerative diseases compared to those who drink less, but this difference is not statistically confirmed.
Middle-aged and older adults who drink 2 to 3 cups of caffeinated coffee per day have an 18–19% lower risk of developing dementia compared to those who drink less, do not drink coffee, or drink decaffeinated coffee. This association does not occur in women.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.