Measurement / residue studyindependent cross-checkfull text checked I-DRY-13 in-depth review

Many aged Italian cheeses contain almost no lactose

Lactose Residual Content in PDO Cheeses: Novel Inclusions for Consumers with Lactose Intolerance.

Overview

Facioni MS et al.. Foods 2021 · PMID 34574346 · DOI 10.3390/foods10092236

All but one of 25 PDO cheeses (even some aged only 20-35 days) had lactose below 10 mg/kg; fresh mozzarella had about 3,500 mg/kg.

Does the study support the specific claim? Partly · Methodological quality: moderate

Original publication

Plain-language summary

Study explained simply

What did the researchers want to find out?: Measure lactose in cheeses.
How was the study done?: Lab analysis.
How many people, animals or samples were studied?: 25 cheeses.
What was actually found?: Lactose below 10 mg/kg in nearly all tested ripened cheeses; starter cultures, not just ageing time, drive lactose loss.
How large was the observed effect?: <10 mg/kg.
What do the results mean in everyday life?: Aged cheese suits lactose-intolerant people.
What are the study's limitations?: Italian/European PDO cheeses only; few samples; no fresh, processed or Egyptian cheeses; funded by a lactose-free certification company.
What does it say about Elawady's specific claim?: Supports the digestibility point for lactose.
Do the results apply to Germany and Europe?: High (Italy).
What can explicitly not be concluded from this study?: Anything about allergy, inflammation or other diseases; lactose content of processed cheese triangles, cream or romi.

Scientific in-depth review

1. Full reference

Authors: Facioni MS et al.
Journal: Foods
Year: 2021
Identifier: PMID 34574346 DOI 10.3390/foods10092236
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. (company behind the Lfree certification mark). COI: M.S. Facioni is a partner of ELLEFREE S.r.l. and president of AILI; S. Dominici and F. Marescotti are partners of ELLEFREE S.r.l. The article promotes the Lfree trademark in its conclusions.

2. Research question

Which PDO cheeses are naturally lactose-free?

3. Study design and population

Study design: Measurement / residue study – Laboratory measurement study: residual lactose in 25 PDO cheeses (21 Italian, 4 foreign; 28 variants by ageing) by HPAEC-PAD and LC-MS/MS in two accredited laboratories, plus interviews with PDO consortia/manufacturers and two online questionnaires (lactose-intolerant consumers and nutrition professionals).
Population: 25 PDO soft, semi-hard and hard cheeses bought in Italian supermarkets (incl. Cheddar, Brie, Emmentaler, Le Gruyere); Mozzarella di Bufala Campana PDO as positive control. Survey: 1,398 lactose-intolerant consumers (91.2% female, mean age 35) recruited via the AILI patients' association on Facebook; 57 nutrition professionals.
Country: Italy
Period: Surveys September-October 2020; cheese sampling during the COVID-19 period (exact dates not stated).
Sample size: 25 PDO cheeses (28 variants), at least 2 batches each from at least 2 factories (4-6 samples per variant); 1,398 consumers; 57 professionals
Inclusion and exclusion criteria: PDO label and supermarket availability; fresh cheeses excluded a priori because of high lactose (whey) content.

4. Methods and endpoints

Exposure / intervention: Cheese type, ageing time, starter culture and production steps.
Comparator: Limit of quantification (LOQ <10 mg/kg); Italian Health Ministry threshold for 'naturally lactose-free' (<0.1 g/100 g); fresh mozzarella as positive control.
Endpoints: Residual lactose (mg/kg); consumer/professional knowledge and behaviour (descriptive).
Statistical methods: Descriptive (mean +/- SD of results from the two laboratories); questionnaire percentages.

5. Actual results

Results: All cheeses except Pecorino Toscano at 20 and 60 days were <LOQ (<10 mg/kg), including short-aged cheeses (Asiago Pressato 20 days, Caciocavallo Silano 30 days, Taleggio 35 days). Pecorino Toscano: 336.8 +/- 44.5 mg/kg at 20 days, 28 +/- 5 mg/kg at 60 days, <LOQ at 4 months. Positive control Mozzarella di Bufala: 3540 +/- 1200 mg/kg (range 2310-5165). Authors identify the starter culture as the primary factor in lactose reduction, whey drainage as secondary, ageing as less decisive than commonly believed. Survey: 54.3% of consumers did not know the difference between naturally lactose-free and 'delactosed' cheese; 77.2% of professionals reported unclear NLF claims.
Absolute risks: not applicable
Authors' conclusion: Most selected PDO cheeses can be considered naturally lactose-free and can be included in a lactose-free diet (preventing calcium/vitamin D shortfalls from dairy exclusion); because PDO specifications allow process variation, case-by-case analysis is needed before declaring a cheese NLF; better labelling (e.g. Lfree mark) is recommended.

6. Strengths

Highly sensitive methods (LOQ <10 mg/kg) with cross-laboratory confirmation
Multiple batches and factories per cheese
Positive control included
Ageing series for Pecorino Toscano

7. Weaknesses

Industry funding and authors' financial interest in lactose-free certification; conclusions promote the authors' trademark
Fresh cheeses, yogurt, processed cheese and Egyptian products (romi, processed triangles) not analysed
Only 4-6 samples per variant; results below LOQ give no actual values
Questionnaire sample self-selected via patients' association (91% female); purely descriptive
Lactose only: no data on allergenicity, casein, immune effects or health outcomes

8. Risk of bias

Orienting tool: none applicable (laboratory measurement study); 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: some concerns
Rationale: Single-reviewer structured judgement from the full text; no standard tool fits a food-composition study. A formal assessment would require two independent reviewers.

8. Risk of bias
Domain	Judgement	Rationale
Analytical validity	low	Two accredited laboratories with two sensitive methods; results agreed; positive control behaved as expected.
Sampling / representativeness	some concerns	Convenience sample of supermarket PDO cheeses, few batches; fresh cheeses excluded; not representative of Egyptian or processed cheeses.
Survey component	high	Self-selected online samples via patients' association; no validation; descriptive only.
Conflict of interest / interpretation	some concerns	Funded by and authored by partners of a lactose-free certification company; analytical results unlikely to be distorted but framing and recommendations favour certification.
Selection of reported results	low	All cheeses tested reported in Table 6.

Full-text review (25 October 2026): Added exact values (Pecorino Toscano 336.8/28 mg/kg, mozzarella control 3540 mg/kg), sampling (2 batches, 2 factories, 2 labs), exclusion of fresh cheeses, survey component (n = 1,398 and 57), funding by ELLEFREE S.r.l. and authors' finding that starter culture rather than ageing time drives lactose reduction. Structured bias judgement added; overall unchanged (some_concerns).

9. Assessment of the statistical interpretation

Descriptive concentrations; '<LOQ' means below 10 mg/kg (0.001%), i.e. negligible lactose relative to milk. Generalisation beyond the sampled batches and PDO cheeses is not possible.

10. Relevance to the specific claim

Supports the lactose part of C-DRY-10 and partially C-DRY-11.

11. Independent contrary findings

n/a

12. Transferability to Germany and Europe

High for Italy; low for Egyptian cheeses.

13. Overall methodological judgement

Reliable demonstration that many ripened (including short-ripened) PDO cheeses contain negligible lactose, while fresh mozzarella contains measurable lactose. Relevant only to lactose tolerance, not to allergy, immune effects or health outcomes; industry COI.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	moderate
Risk of bias	some concerns
Precision of results	not applicable
Directness	indirect
Reproducibility	unknown
Consistency with the overall evidence	unknown
Regional transferability	low
Adequacy of the interpretation (by the archive)	not applicable

14. Open questions

Lactose in Egyptian romi, processed cheese triangles, cream and fresh white cheese; comparison with yogurt; batch variability.