Study analysis · Lancet · 2018
Dairy might be the secret to living longer—here’s what the science actually says.
People who eat more than two servings of milk or yogurt a day are less likely to die early or have a stroke, even in poor countries.
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 watched a lot of people over many years and noticed that those who ate more dairy tended to get sick less often. But it didn't make people change what they ate—it just watched what they already did—so we can't say dairy definitely caused the better health.
What’s the bottom line?
Scientists tracked what people ate and how healthy they were for over 9 years in 21 countries.
How strong is this study?
This study is pretty strong because it looked at over 136,000 people from many countries and followed them for years. But since it didn't control what people ate, we can't be 100% sure the results are all because of dairy—other habits might have helped too.
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=136384)+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
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.
This design cannot establish causation — the findings describe an association, not a cause. This is an observational cohort study without randomization or blinding, so it can identify associations but cannot rule out confounding factors such as lifestyle, socioeconomic status, or other dietary habits that may influence both dairy intake and health outcomes.
No Conflicts
No conflicts of interest identified
No conflicts of interest or funding statements were disclosed in the provided text, and authors are affiliated with academic institutions without apparent industry ties.
The study is part of the PURE cohort, which is known to be funded by multiple sources including non-industry grants, but no funding or COI disclosures are present in this excerpt. Without explicit disclosure, the absence of information cannot confirm independence, but no red flags are present in the provided content.
Key takeaways
- 01
People who ate more than 2 servings of dairy a day had 16% fewer heart problems and 17% lower chance of dying early.
- 02
Milk and yogurt helped, but cheese and butter didn't show clear benefits.
- 03
Yes — eating dairy like milk and yogurt daily may help people live longer and avoid strokes, even in poorer countries.
Surprising findings
- Butter showed no link to increased heart disease or death, despite being high in saturated fat.For decades, saturated fat has been vilified as a heart disease villain—this study suggests butter’s reputation might be undeserved.
- The strongest benefit was for stroke—not heart attacks.Most people assume dairy affects heart attacks most; this study reveals a surprising, specific protective effect on stroke.
Practical takeaways
Replace one daily snack or drink with a serving of milk or yogurt—aim for 2+ total servings per day.
This is observational data—correlation isn’t causation. Don’t start guzzling dairy if you’re lactose intolerant or allergic.
medium confidenceWhy this study matters
Milk and Yogurt = Longevity Boost
People who consumed more than one serving per day of milk or yogurt had a 10–14% lower risk of major cardiovascular events and total mortality. The study tracked over 136,000 adults across 21 countries for nearly a decade.
This challenges the long-standing fear that full-fat dairy causes heart disease—suggesting that everyday foods like milk and yogurt might actually protect you.
Cheese and Butter? Not So Much
Cheese intake showed no significant association with reduced risk, and butter—even though high in saturated fat—had no measurable impact on heart disease or death (HR 1.09, p=0.41).
It flips the script: not all dairy is equal. You don’t need to avoid cheese or butter to be healthy—but milk and yogurt might be the real MVPs.
Stroke Protection, Not Heart Attacks
Dairy intake was linked to a dramatic 34% lower risk of stroke (HR 0.66), but showed no significant link to reduced heart attacks (HR 0.89).
This suggests dairy might protect blood vessels in the brain more than the heart—opening new questions about how saturated fats affect different parts of the body.
Global Impact: Dairy Works Even in Poor Countries
The protective effects held true across low- and middle-income countries, where diets are often less processed and dairy consumption is lower.
This isn’t just a rich-country luxury—dairy might be a simple, affordable tool for improving health worldwide.
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 2 claims from it.