Study analysis · European Journal of Nutrition · 2023
Eating this one dairy product before your cancer diagnosis could cut your death risk by 58% — but this other one could double it.
Before getting colon cancer, eating low-fat dairy like skim milk may help you live longer and keep the cancer from coming back, but eating full-fat dairy like cheese after diagnosis might make you more likely to die.
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 what people with colon cancer ate before and after their diagnosis, and noticed that those who ate more low-fat dairy like skim milk and yogurt tended to live longer. But it didn't make people change what they ate—it just watched what they already did. So we can't say dairy caused them to live longer, just that there's a link.
What’s the bottom line?
This study looked at whether eating dairy like milk, yogurt, or cheese before or after being diagnosed with colon cancer affects survival or cancer coming back.
How strong is this study?
This study did a good job tracking people over time and asking detailed questions about their food, and it adjusted for things like age and smoking. But since people chose their own diets, we can't be sure the dairy was the reason for better outcomes—maybe healthier people just ate more yogurt. That’s why we need to be careful trusting it too much.
40 / 100
- COI disclosure+40/40
- Data availabilitydata not shared
- Code availabilitycode not shared
38 / 100
- Randomizationnot randomized
- Blindingblinding unclear
- Control groupno control group
- Sample size (n=1812)+20/20
- Follow-up+10/10
100 / 100
100 / 100
- P-values+15/15
- Effect size+20/20
- Confidence intervals+15/15
- 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 566 / 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 control group; while it adjusts for confounders, residual confounding and reverse causation cannot be ruled out, so causation cannot be established.
No Conflicts
No conflicts of interest identified
No conflicts of interest or funding disclosures were reported in the study text. The study appears independently conducted with no indication of industry influence.
The study mentions no funding sources, conflict of interest statement, or author affiliations with industry entities. While the study is registered on ClinicalTrials.gov, no funding or COI disclosures are provided in the text, which limits transparency but does not indicate active bias or conflict.
Key takeaways
- 01
People who ate more low-fat dairy (like skim milk or low-fat yogurt) before diagnosis had 58% lower risk of dying and 58% lower risk of cancer returning.
- 02
After diagnosis, eating more low-fat dairy lowered death risk by 24%, but didn't stop cancer from coming back.
- 03
Eating more high-fat dairy (like whole milk or cheese) after diagnosis raised death risk by 60%.
- 04
Yes — these differences are large enough to matter for daily food choices, especially for cancer survivors trying to improve their long-term health.
Surprising findings
- Pre-diagnostic low-fat dairy reduced recurrence risk, but post-diagnostic low-fat dairy did not.Most people assume dietary changes after diagnosis should directly fight cancer — but this study suggests the cancer may already be too far along for diet to stop recurrence, though it still helps overall survival.
- High-fat dairy before diagnosis showed a 41% increased mortality trend — but it wasn’t statistically significant.It’s counterintuitive that high-fat dairy before diagnosis didn’t show a clear harm — suggesting the timing of exposure matters more than we thought.
Practical takeaways
Swap full-fat milk and cheese for skim milk, low-fat yogurt, or cottage cheese — especially after a colorectal cancer diagnosis.
This study was done in the Netherlands with mostly Caucasian participants; results may vary in other populations or with fortified dairy.
medium confidenceIf you're at risk for colorectal cancer, start increasing low-fat dairy now — it may reduce your future recurrence risk by nearly 60%.
Dietary data was self-reported via food frequency questionnaires, which can be inaccurate.
medium confidenceWhy this study matters
Low-fat dairy before diagnosis = 58% lower death risk
People who consumed at least 165g/day of low-fat dairy (like skim milk or low-fat yogurt) before being diagnosed with stage I-III colorectal cancer had a 58% lower risk of dying from any cause and a 58% lower risk of cancer recurrence compared to those eating less than 70g/day.
This suggests your diet years before diagnosis could be a silent protector — meaning small daily choices might have massive long-term consequences for cancer survival.
High-fat dairy after diagnosis = 60% higher death risk
After diagnosis, consuming 81g or more of high-fat dairy (like whole milk, butter, or full-fat cheese) daily was linked to a 60% higher risk of all-cause mortality — even after adjusting for age, treatment, and lifestyle.
It’s not just what you ate before — what you eat after diagnosis actively impacts survival. This flips the script on 'it's too late to change' thinking.
Cheese and milk? No clear link — but why?
Despite being dairy, neither cheese nor milk showed statistically significant associations with recurrence or mortality — suggesting fat content and processing matter more than dairy as a whole.
This challenges the idea that 'all dairy is good or bad' — it’s not about milk or cheese, it’s about fat content and possibly fortification (Dutch milk isn’t vitamin D-fortified like US milk).
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.
- Conflicting evidence
Evidence points in both directions — no clear conclusion yet.
Evidence