Study analysis · Cell metabolism · 2021

Creatine supplements may fuel cancer spread, new mouse study warns.

In mice, creatine helped cancer spread to other organs and shortened survival.

Reading level
Very low certainty
Level 2b · Individual cohort studyAssociation, not causationNo causal claims

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 was done on mice, not people. Mice are different from humans, so we can't be sure the same thing happens in people. It gives us ideas to look into more, but it doesn't prove that creatine makes cancer spread in humans.

What’s the bottom line?

Creatine, a popular muscle-building supplement, was found to help cancer spread in mice. It makes cancer cells more mobile and invasive, leading to more metastases and earlier death in the mice.

How strong is this study?

We don't have all the details about how the study was done because we only read a summary. Without knowing if they used fair methods like random groups and blinding, we can't be sure the results are reliable. It's like hearing a story without knowing if it's true.

Reporting

0 / 100

  • COI disclosureconflicts of interest not disclosed
  • Data availabilitydata not shared
  • Code availabilitycode not shared
Methodology

0 / 100

  • Randomizationrandomization unclear
  • Blindingblinding unclear
  • Control groupno control group
  • Sample sizeno sample size reported
  • Follow-upno follow-up reported
Publication

100 / 100

Statistical

0 / 100

  • P-valuesno p-values reported
  • Effect sizeno effect size reported
  • Confidence intervalsno confidence intervals
  • 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 reviews

Max 100

Randomized Trials

Max 90

Reviews of Cohort Studies

Max 85

Cohort Studies

Max 72

Reviews of Case-Control Studies

Max 63

Case-Control Studies

Max 58

Cross-Sectional & Case Series

Max 50

Expert Opinion

Max 5
StrongerWeaker
Cohort Studies
Level 2b
6

6 / 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 animal study using orthotopic mouse models. Animal physiology and cancer biology may differ significantly from humans. Therefore, causal relationships established in mice cannot be directly extrapolated to humans. The study does not provide human data.

COI Unknown

Could not determine conflict of interest status

No conflicts of interest or funding information provided in the study excerpt.

The text does not contain any conflict of interest disclosures, funding statements, or author affiliations. All assessments are based solely on the provided excerpt.

Key takeaways

  1. 01

    Mice given creatine had more cancer spread to the liver and other organs, and they died sooner than mice not given creatine.

  2. 02

    This is a significant finding for mice, but we don't know yet if it applies to humans.

  3. 03

    More research is needed.

Surprising findings

  • Creatine, widely considered safe and beneficial, promoted metastasis and shortened survival in mice.This contradicts the common perception of creatine as purely beneficial for muscle health and exercise performance.
  • GATM, an enzyme for creatine synthesis, is upregulated in liver metastases, suggesting a feedback loop that fuels spread.Typically, enzymes for nutrient synthesis are downregulated when the nutrient is supplied exogenously, but here both sources contribute to metastasis.

Practical takeaways

Cancer patients or those at high risk should consult a doctor before taking creatine supplements.

This is a mouse study; human relevance is unknown. Full methodology not available for verification.

low confidence

Researchers should investigate GATM and MPS1 inhibitors as potential anti-metastatic drugs.

These findings need validation in human studies and clinical trials.

low confidence

Why this study matters

Creatine's dark side

The study found that dietary creatine supplementation at human-equivalent doses increased metastatic dissemination and reduced survival in orthotopic mouse models of colorectal and breast cancer. This was mediated by upregulation of Snail and Slug via MPS1-activated Smad2/3 phosphorylation.

Creatine is one of the most popular supplements, often taken for muscle growth, but this research suggests a potential risk for cancer patients.

Mechanism revealed: GATM and MPS1

GATM, the rate-limiting enzyme for creatine synthesis, was found to be upregulated in liver metastases. Either dietary creatine or GATM-mediated synthesis activated MPS1, which then phosphorylated Smad2/3, leading to increased Snail and Slug expression and metastasis.

This identifies specific molecular targets that could be blocked to prevent metastasis, even in TGFβ receptor mutant cancers.

Potential therapeutic opportunities

Knocking down GATM or inhibiting MPS1 suppressed metastasis and improved survival in the mouse models. This suggests that targeting these proteins could be a novel strategy to prevent cancer spread, particularly in colorectal and breast cancers.

If validated, this could lead to new drugs that prevent metastasis without interfering with normal creatine functions.

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 Dr. William Wallace cite this study, drawing 2 claims from it.

All 1 video reference this study through extracted claims.