Narrative reviewindependent cross-checkfull text checked I-DRY-14 in-depth review
Lactose intolerance is common and managed by reducing lactose
Nutritional management of lactose intolerance: the importance of diet and food labelling.
Overview
Facioni MS et al.. J Transl Med 2020 · PMID 32590986 · DOI 10.1186/s12967-020-02429-2
Most adults worldwide produce less lactase, but most lactose-intolerant people tolerate small amounts of lactose and usually yogurt; avoiding all dairy may harm bones.
Does the study support the specific claim? Partly · Methodological quality: low
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Diet in lactose intolerance.
- How was the study done?
Narrative review.
- How many people, animals or samples were studied?
n/a
- What was actually found?
Reduce lactose individually; yogurt is usually tolerated; aged hard cheeses are near lactose-free while cream and fresh cheeses contain more lactose; avoid unnecessary total exclusion.
- How large was the observed effect?
70% limited lactase (stated).
- What do the results mean in everyday life?
Individual tolerance matters.
- What are the study's limitations?
Narrative; COI.
- What does it say about Elawady's specific claim?
Supports individual, not general, avoidance.
- Do the results apply to Germany and Europe?
Moderate.
- What can explicitly not be concluded from this study?
General harm of dairy; that yogurt is less tolerable than aged cheese or cream.
Scientific in-depth review
1. Full reference
- Authors
- Facioni MS et al.
- Journal
- J Transl Med
- Year
- 2020
- Identifier
- PMID 32590986 DOI 10.1186/s12967-020-02429-2
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- full text
- Conflicts of interest and funding
Funded by ELLEFREE S.r.l. Competing interests: M.S. Facioni is partner of ELLEFREE S.r.l. and president of AILI; the review promotes the Lfree certification mark created with AILI. Two co-authors supported by Fondazione Umberto Veronesi fellowships.
2. Research question
Dietary management of lactose intolerance that avoids symptoms and nutrient (especially calcium) deficiency, and the role of lactose-free labelling.
3. Study design and population
- Study design
- Narrative review – Narrative review on dietary management of lactose intolerance and labelling.
- Population
Lactose-intolerant people
- Country
Italy (authors)
- Period
n/a
- Sample size
n/a
- Inclusion and exclusion criteria
Not systematic; no search strategy or selection criteria reported.
4. Methods and endpoints
- Exposure / intervention
Lactose from dairy products and 'hidden lactose' in non-dairy foods; lactose-free and plant-based alternatives.
- Comparator
n/a
- Endpoints
Symptoms; nutrient adequacy.
- Statistical methods
None.
5. Actual results
- Results
Narrative statements: about 70% of adults worldwide have limited lactase expression; most lactose-intolerant people tolerate up to 5 g lactose per dose (about 100 mL milk), more with meals; avoidance of all dairy is 'no longer recommended'. Most lactose-intolerant people can eat yogurt without typical symptoms (bacterial beta-galactosidase, slower transit); EFSA accepted a cause-effect relation between yogurt with >=10^8 CFU/g live cultures and improved lactose digestion. Cultured buttermilk and sour cream (mesophilic cultures) are poorly tolerated. Table 1 lactose (g/100 g, estimates from cited sources): whole milk 4.9, cooking cream 3.9, sour cream 3.4, butter 1.1, plain yogurt 2.6, Greek yogurt 0.5, mozzarella 0.7, feta 1.4, cottage cheese 3.2, ricotta 3.5, cheddar 0.5, Fontina 0.8, Emmentaler/Gruyere/Gorgonzola <0.1, Parmigiano/Grana/Pecorino Romano <0.01. Cited observational data: dairy avoidance associated with poor bone health, higher blood pressure and diabetes risk; lactose-intolerant people consume 388-739 mg calcium/day; vegans in EPIC-Oxford had 30% higher fracture risk.
- Absolute risks
not applicable
- Authors' conclusion
Nutritional education and better labelling (a recognisable lactose-free logo) are key to helping lactose-intolerant people avoid lactose-containing products while ensuring adequate nutrient intake; complete dairy exclusion risks calcium deficiency and bone disease.
6. Strengths
- Practical overview of lactose content and dietary options
- Covers nutritional risks of complete dairy exclusion
- Cites EFSA opinion on yogurt and lactose digestion
7. Weaknesses
- Narrative review without search strategy, selection criteria or quality appraisal
- Funded by and partly authored by a lactose-free certification company; promotes its own trademark (Lfree)
- Table 1 values are 'estimates only' compiled from various sources
- Some statements (e.g. extra-intestinal symptoms, prevalence 70%) rely on secondary sources without critical appraisal
8. Risk of bias
- Orienting tool
- none applicable (narrative review); structured judgement of main validity threats
- Type of assessment
- structured assessment based on the full text by a single reviewer (no formal double review)
- Full formal assessment
- no
- Overall risk of bias
- high
- Rationale
Single-reviewer structured judgement from full text; no standard tool fits a narrative review. Low evidential weight; useful as context only. Formal assessment would need two independent reviewers.
| Domain | Judgement | Rationale |
|---|---|---|
| Search and selection of evidence | high | No systematic search or eligibility criteria; selection of cited studies unexplained. |
| Appraisal of cited evidence | high | No risk-of-bias or certainty assessment of cited studies. |
| Conflict of interest | high | Industry funding; first author has financial interest in lactose-free certification promoted in the review. |
| Consistency with authoritative sources | low | Core nutritional statements (lactose threshold ~5 g, yogurt tolerance, calcium risk) align with EFSA and mainstream guidance. |
Full-text review (25 October 2026): Added full-text content: ~5 g lactose tolerance threshold, yogurt generally tolerated (EFSA cause-effect opinion), lactose table (cooking cream 3.9 g/100 g vs plain yogurt 2.6, Greek yogurt 0.5, cheddar 0.5), funding by ELLEFREE S.r.l. and promotion of the Lfree mark. Structured judgement added; overall changed from not_assessable to high (narrative, no methods, industry COI).
9. Assessment of the statistical interpretation
No original data; figures are secondary and lactose contents are rough estimates.
10. Relevance to the specific claim
Context for C-DRY-02, C-DRY-10, C-DRY-11 (lactose intolerance common; risks of total exclusion).
11. Independent contrary findings
n/a
12. Transferability to Germany and Europe
Moderate.
13. Overall methodological judgement
Low-weight but informative context: lactose intolerance is common, but most affected people tolerate small amounts of lactose and yogurt; aged hard cheeses are near lactose-free, whereas cream and fresh cheeses contain substantial lactose. Industry COI.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | low |
| Risk of bias | high |
| Precision of results | not applicable |
| Directness | indirect |
| Reproducibility | unknown |
| Consistency with the overall evidence | unknown |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Lactose content and tolerance of Egyptian products (laban rayeb, labneh, romi, qeshta, processed cheese); regional prevalence data (the 2017 Lancet meta-analysis on this was retracted in 2025 and was not used).
15. Linked fact checks
- Dairy products harm health and cause inflammation. – Studies with mixed or unclear results
- Cooked/processed and aged cheese is the more digestible form of dairy because bacteria have already worked on it; it is fattier, softer, less allergenic and less stimulating to the immune system than milk, yogurt and casein-rich fresh products. – Studies with mixed or unclear results
- Fresh milk, yogurt (incl. laban rayeb, ayran, labneh) and white/cottage cheese are harmful and must be avoided, whereas aged cheeses (cheddar, mozzarella, romi), processed cheese triangles, cream (qeshta), butter and ghee are allowed. – Studies with mixed or unclear results