Mapping Fermented Food Prevalence and Intake Across European Regions: Results from the PIMENTO Study

1. Introduction

Fermented foods and beverages have been part of traditional diets across the globe for centuries. People have long relied on them not only for preserving food but also for their distinctive flavours and cultural significance [1]. In recent years, they have attracted renewed scientific and public health interest due to their potential nutritional and health benefits [2,3,4]. Those are primarily attributed to functional compounds produced during microbial fermentation, such as organic acids, bioactive peptides, bacteriocins, exopolysaccharides, short-chain fatty acids, amino acid derivatives and vitamins [5,6,7]. These foods, produced by the metabolic activity of microorganisms, can enhance nutrient bioavailability, support gut and metabolic health, and mental health [8]. Moreover, they may introduce live microbes that may exert probiotic-like effects [9,10,11]. Emerging evidence also suggests that fermented foods may contribute to gut microbiome diversity, immune modulation, and metabolic regulation, although mechanistic insights and clinical validation remain limited [12,13].

The global diversity of fermented products is well documented, ranging from dairy and cereal-based foods to fermented vegetables, legumes, and beverages [13,14], reflecting their cultural and nutritional significance. These differences represent not only the culinary heritage but also the influence of local agricultural systems, further highlighting the nutritional and socio-cultural importance of fermented foods [15,16]. European fermented food traditions demonstrate substantial regional diversity with marked variation in product types, preparation methods, consumption frequency, and portion sizes [17,18,19].

Despite their prevalence, comprehensive data on the consumption patterns of fermented foods across Europe remain scarce. Existing studies typically concentrate on specific food types or on the consumption patterns of individual countries [19,20,21,22,23], limiting the ability to assess broader trends and demographic influences. Moreover, the lack of standardised definitions, variation of serving sizes, and regulatory frameworks for fermented foods complicates research reproducibility and consumer transparency [24]. Large-scale European studies, such as the European Prospective Investigation into Cancer (EPIC) InterAct study [25], apply standardised dietary assessment methods but, to date, have captured only limited characteristics of fermented foods required for a comprehensive classification across all major food groups. This gap hinders efforts to develop evidence-based dietary guidelines and to conduct robust nutritional epidemiology research exploring associations between fermented food intake and health outcomes.

Traditional food frequency questionnaires (FFQs) and national nutrition surveys often fail to capture the full diversity of fermented products or omit, for example, less conventional but increasingly relevant plant-based alternatives [26]. Moreover, many previous studies have relied on FFQs with limited definitions of fermented foods, potentially overlooking major food items consumed by the target populations. For instance, a recent study in Japan [27] demonstrated the complexity of identifying and quantifying fermented foods, including partially fermented products, highlighting their substantial contribution to energy and nutrient intake. Overall, these findings indicate the need for a more comprehensive and standardised approach to assessing fermented food consumption.

To address this critical gap, we have recently developed the Fermented Food Frequency Questionnaire (3FQ) under the Promoting Innovation of Fermented Foods [28] COST Action (CA20128) [29]. The 3FQ is the first validated tool specifically designed to assess habitual consumption of a broad range of fermented food categories across multiple European countries, enabling standardised comparisons, while accounting for local food environments. Thus, this tool could offer a strong foundation for advancing research and informing evidence-based policy. Using the 3FQ, consumption prevalence and intake of the fermented food groups studied, were collected across four European regions [30,31]. The present study aims to characterise fermented food consumption patterns among European populations and assess regional differences across major food groups.

2. Materials and Methods

Study Population and Data Collection

The current study is based on cross-sectional survey data collected using an online version of the 3FQ from adults residing in European countries between October 2023 and May 2024, conducted under the PIMENTO COST Action CA20128 framework. The questionnaire was initially developed in English by experts in food science and technology, nutrition, nutritional epidemiology, and consumer science. It was translated into 27 other languages by National Contact Points (NCPs) from participating countries using a standardised back-translation methodology. The study received approval from the Ethics Committee of the Agricultural University of Athens (27/05.05.2023) and adheres to the principles of the Declaration of Helsinki regarding research with human participants [32]. The study targeted to obtain representative samples per European region, with a minimum estimate of 1,536 per European region, as per STEP process (total N=6,144), stratified by sex and age group (18-49.9 years and ≥50 years). The European regions targeted included: Western Europe: Austria, Belgium, France, Germany, Ireland, Liechtenstein, Luxembourg, Andorra, Monaco, Netherlands, United Kingdom, Switzerland; Northern Europe: Estonia, Finland, Faroes, Iceland, Latvia, Lithuania, Norway, Denmark, Sweden; Central and Eastern Europe: Albania, Armenia, Azerbaijan, Georgia, Hungary, Poland, Romania, Bulgaria, Belarus, Bosnia and Herzegovina, Croatia, Kosovo, North Macedonia, Montenegro, Moldova, Slovakia, Czechia, Russia, Serbia, Slovenia and Ukraine; Southern Europe: Gibraltar, Greece, Italy, Malta, Portugal, San Marino, Türkiye, Holy See, Cyprus, Spain as defined by the EuroVoc [31]. All participants were asked to provide an informed consent via a General Data Protection Regulation (GDPR)-compliant platform (Conjointly, https://conjointly.com/ ) prior to data collection. The data used in the current analysis were fully anonymised, as no IP addresses were included and no other contact details were included in the database. The details of the development, implementation, and validation of the 3FQ have been previously reported [29,30]. Briefly, the core study sample comprised 12,646 participants from 53 countries, distributed across the four European regions: Northern Europe (n=9), Southern Europe (n=10), Central and Eastern Europe (n=22), and Western Europe (n=12).

Assessment of the Consumption of Fermented Foods

The 3FQ was developed to map the frequency and quantity of fermented food consumption across European regions, covering a diverse range of food categories, including 15 primary groups with multiple subcategories for each main group. These groups included plant-based meat and/or dairy alternatives; fermented dairy products; fermented pulses and legumes; fermented meat and/or fish products; fermented vegetable products; fermented cereal products; chocolate; fermented non-alcoholic beverage products; vinegar; coffee; fermented tea; cocoa beverages; beer or cider; wine and strong spirits. A screening, yes/no consumption question was primarily asked for each main fermented food group. If the response was positive, details on the frequency and quantity of subcategories within each food group followed. The screening question was used for two reasons: (i) to decrease response burden and move to the next food group, if one was not consumed, and (ii) to assess participants’ awareness of actual fermented foods per food group, using specific examples. Frequency of consumption for each food group was defined using predetermined categories ranging from “Never” to “Daily, more than two times” to standardise responses across individuals. To increase accuracy and consistency in dietary reporting, the questionnaire incorporated portion-validated food pictures, enabling participants to visually estimate and select the portion sizes that most closely represent their usual intake. Images were selected in consultation with nutrition professionals and, where possible, were aligned with data population intakes from national surveys. Each image was catalogued in a database linking visual cues to specific portion weights and standard household measures. Participants were asked to indicate the portion size most representative of their typical consumption, thereby minimising measurement errors and improving data reliability. Details of the 3FQ derivation can be viewed in the published protocol [30].

Demographic, Anthropometric and Health Data

The first part of the 3FQ collected general demographic information and self-reported anthropometric data. The participants’ educational levels were categorised according to international education standards (International Standard Classification of Education - ISCED). These included 4 categories: Primary (>6 years); Secondary (≥6-12 years); Bachelor’s University; and Postgraduate (MSc/PhD). Employment status was classified according to the Eurostat/International Labour Organization (ILO) labour force status standards. Specifically, participants were categorised as: employed full-time, employed part-time, not employed but a student, retired, unemployed, or a homemaker. Reported information on weight and height was used to calculate participants’ weight status using the Body Mass Index (BMI = weight in kilograms/height in meters. Participants were then categorised according to the World Health Organisation criteria [33]. (BMI < 18.5 indicates underweight; BMI 18.5–24.9 indicates normal weight; BMI ≥ 25.0 indicates overweight; BMI ≥ 30.0 indicates obesity). Information on marital and smoking status was also collected, along with questions about their health status (any chronic conditions and comorbidities), as these factors may affect knowledge and behaviour regarding fermented food consumption.

Participants were also asked to report whether they had a background in nutrition or food science. Sensitivity analyses were conducted to assess differences in consumption patterns between the total population and the population after excluding participants with a background in nutrition or food science.

Data Analysis

The population sample for the current study was adjusted to match the actual population sizes in each European region, with post-stratification weights across European regions, sex, and age groups to achieve comparability with the population structure. Observations were excluded from the analysis when regional population data were missing, preventing the assignment of weights. Socio-demographic characteristics and data on individual health conditions, as well as fermented foods consumption data, were presented using survey design analysis weighted by European region, as determined by the sampling structure and the latest population census. Categorical variables were presented proportionally to each region’s population. Pearson χ² tests were performed to determine differences in regional distributions. Continuous variables were checked via P-P and k-density plots to determine whether they follow normal or skewed distribution and are presented as mean ± standard deviation (SD) and as median and range (25th, 75th percentiles), respectively. Between-group differences were tested using Analysis of variance (ANOVA) or the Kruskal-Wallis test for parametric and non-parametric continuous variables, respectively. Heatmaps were generated to portray consumption patterns and low-moderate and high response prevalence with corresponding intakes were derived and compared. Significance for all analyses was set at p<0.05. Database cleaning and statistical analysis were performed using Stata 18.0 (StataCorp, Texas Ltd.).

3. Results

Study Population Demographics

The socio-demographic and anthropometric characteristics of the study population by European Region are summarised in Table 1. Detailed characteristics of the study population by sex and age group are presented in Supplementary Materials, Tables S1 and S2, respectively. The total sample comprised 12,646 participants from 53 European countries across the four EuroVoc regions: Northern Europe (n = 2,315), Central-Eastern Europe (n = 5,185), Western Europe (n = 2,577) and Southern Europe (n = 2,569). Weighted values were applied to derive all results, and statistical analyses indicated significant differences between regions for all socio-demographic and health variables reported (Table 1). The median age ranged from 39 to 45 years, with the lowest median observed in Central-Eastern Europe and the highest in Northern Europe. Despite variations in sex distribution, women were the most prevalent respondents across all regions.

In terms of body weight, the Western Europe sample had the highest prevalence of normal weight (65.8%) and the lowest obesity rate (7.8%), whereas participants from Northern Europe exhibited the highest obesity prevalence (18.2%). Educational attainment was highest in Western Europe participants, with 54.6% holding postgraduate qualifications, followed by Southern Europe (39.9%), compared to 30.3% in Central-Eastern Europe.

Prevalence of Fermented Foods Consumption by European Region

Before answering questions on frequency and intake, respondents first specified for each fermented food category whether they consumed fermented foods from the specific product categories. Significant regional differences in the prevalence of fermented food consumption were observed across 14 of 15 categories (p<0.001 for all; Table S3, Figure 1). Fermented dairy products were the most widely consumed fermented foods across all regions (prevalence of 94.1% to 95.6%) and were the only category without significant regional variation, although a potential trend was observed (p = 0.059). Other highly consumed categories included fermented cereal products (89.9% to 95.9%) and coffee (78.4% to 84.1%). Heatmap visualisation (Figure 1) revealed three distinct consumption tiers: i) High prevalence of consumption (≥75%), which included fermented dairy products, chocolate, fermented cereals, fermented vegetables, and coffee, which were consistently consumed across regions; ii) Moderate prevalence of consumption (50–75%) including fermented meat/fish products, vinegar, wine, fermented pulses/legumes, and beer or cider that demonstrated intermediate consumption with notable regional variation; iii) Low prevalence of consumption (<50%) comprising of fermented non-alcoholic beverages, plant-based meat/dairy alternatives, cocoa beverages, and fermented tea that exhibited the lowest prevalence, with pronounced disparities. For instance, the prevalence of plant-based alternative consumers was substantially higher in Western Europe (72.8%) than in other regions (<52%), whereas the prevalence of fermented non-alcoholic beverage consumers was the lowest in Southern Europe (18.3%). Details of population-derived 95% CIs are provided in Supplementary Materials Table S3. The lowest consumption prevalence was observed for fermented tea (33.8% in Northern Europe to 44.3% in Central-Eastern Europe), while the most significant regional disparities were observed for plant-based meat/dairy alternatives (44.4% in Central-Eastern Europe vs. 72.8% in Western Europe) (Figure 1). Western Europe reported high consumption prevalence across most categories, except for strong spirits, cocoa beverages (moderate), fermented non-alcoholic beverages, plant-based alternatives, and fermented teas (low prevalence). Fermented pulses and legumes were highly consumed only in Western Europe (80.5%) but moderately in other regions (59.4%–67.6%). Similar patterns were observed for vinegar, wine, beer/cider, and plant-based alternatives. Fermented meat/fish products showed a moderate reported consumption prevalence in Southern Europe (62.5%), but were higher in the other regions, ranging from 75.5% in Western Europe to 83.2% in Central and Eastern Europe.

Intake Amounts of Fermented Foods Among Consumers

Among consumers, intake amounts varied substantially across regions and food groups (Table 2, Figure 2). Three main intake tiers were identified: (i) Low (0 to 50 g/day); (ii) Moderate (51 to 100 g/day); and (iii) High (>101 g/day). No fermented food category exceeded 101 g/day among daily consumers. Moderate daily intake was observed for fermented dairy and coffee across all regions, and for cereals only in Northern, Southern and Western Europe. Specifically, fermented dairy products had the highest median daily intake (66.7 g/day in Central-Eastern Europe to 80.1 g/day in Western Europe; p<0.001). Fermented yoghurt and milk ranged from 44–55.7 g/day, while cheese ranged from 5–20 g/day.

Coffee intake ranged from 60.0 ml/day in Southern and Central-Eastern Europe to 73.1 ml/day in Northern Europe (p<0.001). Fermented cereals ranged from 44.0 g/day in Central-Eastern Europe to 77.1 g/day in Northern Europe (p<0.001). Among alcoholic beverages, wine intake was highest in Western Europe (25.0 ml/day) compared to 12.5 ml/day in Central-Eastern Europe (p<0.001). Beer/cider ranged from 25.0 ml/day in Central-Eastern Europe to 45 and 50.0 ml/day in Northern and Western Europe, respectively (p<0.001).

Lastly, fermented vegetables showed one of the lowest daily intakes among groups, ranging from 2.1 g/day in Southern Europe to 8.4 g/day in Central-Eastern Europe.

For weekly consumption, chocolate showed the highest intake, with Western and Central-Eastern Europe reaching 138.8 g/week vs. 76.0 g/week in Northern Europe (p<0.001). Cocoa beverage consumption was consistent across regions (~66.4 ml/week; p<0.001). Plant-based alternatives had low weekly intake despite high prevalence, with only Western Europe showing measurable intake (25.5 g/week; others = 0; p<0.001). Fermented non-alcoholic beverages varied widely (18.7 ml/week in Southern Europe to 49.8 ml/week in Western Europe; p<0.001). Fermented meat/fish and vegetables also had low intakes: meat/fish ranged from 5.6 g/week in Southern Europe to 23.5 g/week elsewhere. Pulses/legumes were minimal (4.5 to 9.0 g/week), and fermented tea was negligible (0 in Western Europe to 16.6 g/week in Southern Europe; p<0.001).

Sensitivity analyses confirmed that regional differences persisted for most categories (e.g., cereals, vegetables, coffee, wine, beer/cider, chocolate), with most p-values remaining significant (<0.001). Some categories showed attenuated significance, such as fermented meat and fish, and some teas and beer, although differences remained.

Relationship Between Consumption Prevalence and Intake Amounts

A notable discordance was observed between consumption prevalence and actual intake amounts across several fermented food categories. Despite a near-universal consumption of fermented dairy products (94–96%), median daily intake remained moderate (66–80 g/day), suggesting frequent, small portions rather than large servings. Similarly, plant-based meat/dairy alternatives showed high prevalence of consumers in Western Europe (72.8%), but a negligible weekly intake (median 25.5 g/week), indicating sporadic or minimal consumption. Conversely, chocolate was widely consumed (91–96%) with a substantial weekly intake (76–139 g/week), particularly in Western and Central-Eastern Europe. In contrast, fermented non-alcoholic beverages displayed the opposite trend: a low prevalence of consumption (18–49%) but relatively higher weekly intake among consumers (19–50 g/week), suggesting that while few people consume these products, those who do tend to do so regularly and in larger quantities.