Nezam El-Tayebat Fact CheckA scientific assessment of the “نظام الطيبات” nutrition system
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Potentially true Overinterpreted Certainty of evidence: low provisional C-SOD-09

Cola consumption damages the kidneys (chronic kidney disease).

In short: Possibly true but overstated: a large UK cohort links more than one soft drink a day with about 20% higher risk of chronic kidney disease, but the evidence is observational, not cola-specific, and does not show that cola itself damages the kidneys.
Conclusion: Possibly true but overstated: soft drinks are modestly linked with chronic kidney disease in a large cohort, but causation is not shown.
  1. Original statement
  2. Scientific assessment
  3. Scientific evidence in detail
  4. In plain language
  5. Studies on this claim
  6. Regional context
  7. What applies in my country?
  8. References

Original statement

النتيجة المتراكمة في الأبحاث: زيادة وزن، سكري، قلب، سكتة، كلى، كبد دهني، نقرس، تسوس، وارتفاع الوفاة المبكرة.

verbatim according to source. Translation by the project; the Arabic wording is authoritative.

Translation

Cola consumption damages the kidneys (chronic kidney disease).

Origin

Source status
Archive editors
Attribution
Archive editors (study selection and narrative are the archive's, not necessarily Elawady's)
Origin
https://eltayebat.com/rule/soda/
Attribution uncertainty
The archive homepage states that the forbidden-food section is supported by research 'independently of Dr. Diaa's words'. No evidence was found that Elawady himself cited these studies.
Claimed mechanism

Phosphoric acid; urinary changes.

Claimed health effect

Chronic kidney disease.

Population concerned

Adults

Geographic restriction by Elawady

none found

Scientific assessment

Potentially true – Some evidence points in favour of the statement, but it is not sufficient for a clear judgement.

Certainty of evidence: low – Further research is likely to change the assessment considerably.

1. What was claimed?

Sodas harm the kidneys.

2. What is demonstrably correct?

Saldana 2007 (A-SOD-13): >=2 colas/day associated with chronic kidney disease (OR 2.3, 1.4-3.7); non-cola carbonated drinks were not. A large prospective cohort (I-SOD-125) found more than one sugary or diet soft drink a day associated with modestly higher CKD risk (HR 1.19 and 1.26).

3. What is wrong or exaggerated?

'Damages the kidneys' implies proven causation, which observational data cannot show. The prospective evidence concerns soft drinks generally, not cola specifically, and diet drinks showed a similar association, suggesting that other factors (diabetes, obesity, overall diet) may explain part of the link. A meta-analysis found the pooled association non-significant (I-SOD-126).

4. What remains unclear?

Whether there is any causal effect, and whether cola differs from other soft drinks.

5. Which studies support it?

I-SOD-125 (UK Biobank cohort), A-SOD-13 (case-control).

6. Which studies contradict it?

I-SOD-126 (pooled association not statistically significant).

7. What applies to Germany and Europe?

No EU data reviewed.

8. What is known about Egypt?

No Egypt-specific data.

9. What practical conclusion is appropriate?

Replacing soft drinks with water is reasonable and may benefit the kidneys; firm proof of harm from cola is lacking.

Assessment details

Rationale for certainty of evidence

A prospective UK Biobank cohort of 127,830 adults followed for 10.5 years (I-SOD-125) found >1 SSB/day associated with 19% higher and >1 ASB/day with 26% higher CKD incidence; a 2021 meta-analysis (I-SOD-126) found a positive but non-significant pooled association with a dose-response above seven servings per week. The older case-control study (A-SOD-13) was cola-specific but prone to bias. Observational data, no cola-specific prospective analysis, and the similar diet-drink association suggest confounding.

Source quality

Archive lists the study in its bibliography and includes 'kidneys' in its summary without qualification.

Regional transferability

Low (old US case-control).

Individual exceptions

Not applicable.

Regional scope of the claim
general (biological/medical)
Last reviewed
26 October 2026 provisional

Scientific evidence in detail

Overinterpreted – A real finding exists, but the claim draws more from it than the data allow (e.g. association taken as cause, animal data applied to humans, small effect presented as large).

Research question: Is cola (soft drink) consumption associated with chronic kidney disease?

Research question in detail (PECO)
Population
Adults
Intervention or exposure
Cola/SSB/ASB
Comparison
Low or no intake
Geographic scope
universal
Outcomes
  • Incident CKD

Study results as reported by the authors. Our assessment follows below.

What speaks for the claim?

What speaks against the claim?

What does the overall evidence say?

Editorial assessment based on the studies above – not itself a study result.

Which position is better supported?

Soft drinks are modestly associated with incident CKD in a large cohort; causation and cola specificity are not established.

Why some studies weigh more

Large prospective cohort outweighs a 1980s case-control study.

Is a causal relationship established? Possible, not established Plausible via diabetes, obesity and hypertension; ASB association suggests confounding.

Remaining uncertainty

Causality; cola-specific effect.

Justified conclusion

Possibly true; 'damages' is overstated.

Why do studies seem to disagree?

Heo (significant) vs Lo (non-significant pooled): Lo pre-dates Heo and pooled few small studies.

Does this depend on the country?
General biological effects
Universal.

A regional difference that changes the conclusion is not supported by robust data.

Statistical re-check
  • Log-symmetry; illustrative absolute excess – Symmetric; 3.5% cumulative CKD; ~0.7 percentage points excess over 10.5 years at HR 1.19 (approximation) recalculated
Certainty of the overall evidence (GRADE, simplified)
Main outcome
Incident CKD with soft drinks
Starting level
low (observational studies)
Reasons for downgrading
  • risk of bias (confounding)
Result
low

Simplified assessment by a single reviewer, following the GRADE approach; not a formal GRADE panel. GRADE rates the body of evidence for one outcome, not individual studies.

Search strategy

Documented literature searches for this review (search strings in the original database syntax).

DatabaseDateSearchLooking forHitsIncluded
PubMed26 October 2026(soda[tiab] OR cola[tiab] OR soft drink*[tiab] OR sugar-sweetened beverage*[tiab] OR carbonated beverage*[tiab]) AND (chronic kidney disease[tiab] OR CKD[tiab] OR kidney function[tiab]) AND (meta-analysis[pt] OR cohort[tiab])both directions27

Open questions

Cola-specific and phosphate-specific analyses.

How deeply was this checked?

3 linked studies: 0 checked in full text (0 of them with a structured risk-of-bias assessment), 3 on the basis of the abstract, 0 bibliographically only. No formal assessment with two independent reviewers and no independent human expert review has taken place yet.

Last scientific review: 26 October 2026

History of the verdict
  1. 25 October 2026 · Phase 1 · Initial assessment: Unclear / insufficient evidence (very low)
  2. 26 October 2026 · Phase 4 (systematic evidence review) · Verdict changed: Unclear / insufficient evidence (very low) → Potentially true (low)
    Changed because the evidence base changed materially: a 127,830-person prospective cohort with 10.5-year follow-up now shows a modest association, replacing a single 1980s case-control study; causation remains unproven.
    New sources: I-SOD-125 I-SOD-126

In plain language

A large British study following about 128,000 adults for ten years found that people drinking more than one sugary or diet soft drink a day developed chronic kidney disease somewhat more often (about 20% more). An older, smaller study had found a link specifically for cola. These studies cannot prove that the drinks cause kidney damage, because people who drink many soft drinks may differ in other ways.

Studies on this claim

Studies supporting the claim (1)

  • Soft drinks linked to slightly more kidney disease

    Heo GY et al.. JAMA Netw Open 2024 · PMID 38416492 · DOI 10.1001/jamanetworkopen.2023.56885
    Cohort studyindependent cross-checkabstract checked★ key study

    Among 127,830 UK adults, drinking more than one sugary or diet soft drink a day was linked to 19-26% higher risk of chronic kidney disease.

    SSB >1/day HR 1.19; ASB >1/day HR 1.26 for incident CKD.

    Does the study support the specific claim? Partly · Methodological quality: high · Certainty of evidence: see overall assessment of the claim

    Original publication · Scientific details

    Study explained simply
    What did the researchers want to find out?

    Examine sweetened drinks and kidney disease.

    How was the study done?

    UK Biobank cohort over about 10 years.

    How many people, animals or samples were studied?

    127,830 adults; 4459 CKD cases.

    What was actually found?

    Sugary and diet drinks linked to more CKD; juice not.

    How large was the observed effect?

    HR 1.19 (SSB), 1.26 (ASB).

    What do the results mean in everyday life?

    Replacing soft drinks with water may be good for kidneys.

    What are the study's limitations?

    Observational; not cola-specific.

    What does it say about Elawady's specific claim?

    Supports a modest link; does not prove damage.

    Do the results apply to Germany and Europe?

    UK data.

    What can explicitly not be concluded from this study?

    Cannot prove causation.

    Scientific details →

Studies contradicting or limiting the claim (0)

No studies in this group.

Studies with mixed or unclear results (2)

  • Cola and kidney disease

    Saldana TM et al.. Epidemiology 2007 · PMID 17525693 · DOI 10.1097/EDE.0b013e3180646338
    Case-control studycited by the Tayebat archiveabstract checked

    People with kidney disease more often reported drinking two or more colas a day; authors called this preliminary.

    Does the study support the specific claim? Partly · Methodological quality: low · Certainty of evidence: see overall assessment of the claim

    Original publication · Scientific details

    Study explained simply
    What did the researchers want to find out?

    Are carbonated beverages (cola) associated with CKD?

    How was the study done?

    Case-control study.

    How many people, animals or samples were studied?

    465 cases; 467 controls; Newly diagnosed CKD patients and community controls

    What was actually found?

    >=2 colas/day OR 2.3 (1.4-3.7); regular colas 2.1 (1.3-3.4); artificially sweetened colas 2.1 (0.7-2.5 as printed); non-cola 0.94 (0.4-2.2).

    How large was the observed effect?

    OR 2.3 (1.4-3.7)

    What do the results mean in everyday life?

    Possible signal only.

    What are the study's limitations?

    Case-control: recall and selection bias; Old data; Small

    What does it say about Elawady's specific claim?

    Only evidence for C-SOD-09.

    Do the results apply to Germany and Europe?

    Low.

    What can explicitly not be concluded from this study?

    That cola damages kidneys.

    Scientific details →

  • Pooled studies: soda-kidney link uncertain

    Lo WC et al.. J Nephrol 2021 · PMID 33502726 · DOI 10.1007/s40620-020-00957-0
    Meta-analysisindependent cross-checkabstract checked

    A meta-analysis found a non-significant 30% higher kidney-disease risk with high sugary-drink intake, with risk rising above seven drinks per week.

    Pooled RR 1.30 (0.88-1.94), non-significant; dose-response above 7/week.

    Does the study support the specific claim? Partly · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim

    Original publication · Scientific details

    Study explained simply
    What did the researchers want to find out?

    Pool studies on sweetened drinks and kidney disease.

    How was the study done?

    Meta-analysis.

    How many people, animals or samples were studied?

    About 25,000 people.

    What was actually found?

    Higher risk estimates, not statistically certain.

    How large was the observed effect?

    RR 1.30 (0.88-1.94).

    What do the results mean in everyday life?

    The link is possible but uncertain.

    What are the study's limitations?

    Few studies.

    What does it say about Elawady's specific claim?

    Neither proves nor disproves the claim.

    Do the results apply to Germany and Europe?

    Applicable.

    What can explicitly not be concluded from this study?

    Cannot prove causation.

    Scientific details →

Regional context

Germany / EU

No EU data reviewed.

Egypt

No Egypt-specific data.

What applies in my country?

General scientific assessment

Potentially true Possibly true but overstated: soft drinks are modestly linked with chronic kidney disease in a large cohort, but causation is not shown.

The following areas of food safety are relevant to this statement:

  • Additives and processing

Honey, sugar, sweets

Choose a country to see the checked information for it.

Limits: legal rules describe what is allowed, not what every single food contains. Measurement data come from samples and are meaningful only together with their method details.

Country of residence or purchase Compare with another country

References

  1. Sweetened Beverage Intake and Incident Chronic Kidney Disease in the UK Biobank Study.. Heo GY et al.. JAMA Netw Open 2024 · PMID 38416492 · DOI 10.1001/jamanetworkopen.2023.56885
  2. Carbonated beverages and chronic kidney disease.. Saldana TM et al.. Epidemiology 2007 · PMID 17525693 · DOI 10.1097/EDE.0b013e3180646338
  3. Sugar- and artificially-sweetened beverages and the risks of chronic kidney disease: a systematic review and dose-response meta-analysis.. Lo WC et al.. J Nephrol 2021 · PMID 33502726 · DOI 10.1007/s40620-020-00957-0

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