Study analysis · International journal of epidemiology · 2025
Drinking milk daily could cut your stroke risk by nearly 20% — but yogurt and cheese? Not so much.
People in Japan who drink milk almost every day are a little less likely to die, especially from stroke, but eating yogurt or cheese doesn’t seem to help.
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 looked at lots of people in Japan and found that those who drank more milk tended to live longer, but it didn’t make them drink milk—it just watched what they already did. So we can’t say milk made them live longer, just that the two things happened together.
What’s the bottom line?
Scientists looked at data from 400,000 Japanese adults to see if eating dairy like milk, yogurt, or cheese affects how long people live.
How strong is this study?
The study is pretty big and looked at people for a long time, which is good, but it relied on people remembering what they ate, which isn’t always accurate. Also, we don’t know if they accounted for other things like smoking or exercise, so we can’t be super sure the results are trustworthy.
0 / 100
- COI disclosureconflicts of interest not disclosed
- Data availabilitydata not shared
- Code availabilitycode not shared
38 / 100
- Randomizationnot randomized
- Blindingblinding unclear
- Control groupno control group
- Sample size (n=398690)+20/20
- Follow-up+10/10
100 / 100
77 / 100
- P-values+15/15
- Effect size+20/20
- Confidence intervals+15/15
- Pre-registrationnot pre-registered
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 552 / 100
Probability of being correct
Systematic reviews and meta-analyses of cohort studies. They sit above a single cohort study but below a single randomized trial, because the underlying evidence is still observational.
This design cannot establish causation — the findings describe an association, not a cause. This is a systematic review of observational cohort studies, which can identify associations but cannot rule out confounding factors like diet, lifestyle, or socioeconomic status that may influence both dairy intake and mortality.
No Conflicts
No conflicts of interest identified
No conflicts of interest or funding information were disclosed in the provided text.
The study appears to be an independent pooled analysis of Japanese cohorts with no disclosed funding sources, author affiliations, or conflict of interest statements. Without additional information, no bias or industry influence can be inferred.
Key takeaways
- 01
People who drank milk almost every day were 6% less likely to die from any cause, and 19% less likely to die from stroke (brain-related death) compared to those who drank milk less than once a week.
- 02
Eating yogurt or cheese didn’t seem to make a difference.
- 03
The reduction in risk is small but consistent across many people over many years — it suggests daily milk might help slightly lower the chance of dying, especially from stroke.
Surprising findings
- Yogurt and cheese showed no association with reduced mortality despite widespread belief in their health benefits.Most public health messaging promotes fermented dairy as beneficial for longevity, yet this large study found no link — especially surprising in a population with low overall dairy intake.
Practical takeaways
If you enjoy milk, drinking it daily may slightly lower your risk of stroke and early death — especially if you're in a population with low dairy intake.
This study only looked at Japanese adults; results may not apply to other populations, and dairy isn't the only path to longevity.
low confidenceWhy this study matters
Milk = Lower Stroke Risk
Daily milk consumption was linked to an 19% lower risk of cerebrovascular death in Japanese men (HR: 0.81) and a 10% lower risk in women (HR: 0.90), compared to those drinking milk less than once a week.
Most people assume all dairy is equal — but this study suggests milk might have unique benefits for brain health that yogurt and cheese don’t share.
No Dose-Response Mystery
People in the second and third quartiles of total dairy intake had lower all-cause mortality, but increasing intake beyond that didn’t improve outcomes — suggesting a 'sweet spot' rather than 'more is better.'
It flips the common nutrition advice that more of a good thing is always better — here, moderation might be the real key.
Yogurt and Cheese Show No Benefit
Despite being popular health foods, yogurt and cheese intake showed no significant association with reduced mortality in either men or women.
This contradicts mainstream wellness trends that promote yogurt for gut health and cheese for protein — here, they didn’t move the needle on lifespan.
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.
Standing
Who’s using this study?
The videos and claims on this site that lean on this study, and the researchers who wrote it.
1 video from Physionic cite this study, drawing 1 claim from it.
- Contradicted
Evidence contradicts this claim.
Evidence