- Intake of estragole from fennel-containing plant food supplements (PFS) was moderate.
- Intake of trans-anethole from fennel-containing PFS was lower than ADI value.
- Intakes of beneficial compounds from PFS were low compared with dietary intake.
- First intake estimates of p-coumaric and rosmarinic acids are presented.
The purpose of this study was to estimate the intake of selected bioactive compounds from fennel-containing plant food supplements (PFS) among Finnish consumers. The estimated average intake of estragole was 0.20 mg/d, of trans-anethole 1.15 mg/d, of rosmarinic acid 0.09 mg/d, of p-coumaric acid 0.0068 mg/d, of kaempferol 0.0034 mg/d, of luteolin 0.0525 μg/d, of quercetin 0.0246 mg/d, of matairesinol 0.0066 μg/d and of lignans 0.0412 μg/d. The intakes of kaempferol, quercetin, luteolin, matairesinol and lignans from PFS were low in comparison with their dietary supply. The intake of estragole was usually moderate, but a heavy consumption of PFS may lead to a high intake of estragole. The intake of trans-anethole did not exceed the acceptable daily intake, but PFS should be taken into account when assessing the total exposure. To our knowledge, this study provided the first intake estimates of trans-anethole, p-coumaric acid and rosmarinic acid in human populations.
- Dietary supplements;
- Bioactive compounds;
Food supplements are concentrated sources of nutrients or other substances with a nutritional or physiological effect, the purpose of which is to supplement the normal diet. They are marketed in dose form, for instance as pills, tablets, capsules and liquids in measured doses. Plant food supplements (PFS) contain one or more botanical ingredients. They have a long tradition of use, and are widely consumed in many European countries. However, comparable data on the consumption of PFS on the European level are scarce, and little is known about the risks and benefits associated with their consumption. The PlantLIBRA project aims to develop, validate and disseminate data and methodologies for the risk and benefit assessment of PFS, and to implement sustainable international cooperation related to PFS (PlantLIBRA, 2010).
Fennel (Foeniculum vulgare) is a perennial aromatic herb. In pharmacopoeias and well established documents fennel has been described as being used in the symptomatic treatment of dyspepsia ( Weiss, 1991), as an expectorant for mild inflammation of the upper respiratory tract ( Weiss, 1991) and in the treatment of dysmenorrhea and pain in scrotal hernia ( Pharmacopoeia of the People’s Republic of China, 2000). In traditional medicine, fennel is used in the treatment of many types of symptoms ( Hare, Caspari, & Rusby, 1916).
According to the results of the PlantLIBRA PFS Consumer Survey conducted in Finland, Germany, Italy, Romania, Spain and the UK, fennel ranked sixth in the pooled list of most consumed botanicals (Garcia-Alvarez et al., 2014). Among the Finnish subsample, fennel ranked 31th. The essential oil of fennel, extracted from fennel seeds, contains trans-anethole and estragole, among other compounds. Both have exhibited antimicrobial activity (Friedman, Henika, & Mandrell, 2002), but trans-anethole has also displayed tumorigenic properties in laboratory animals (Joint FAO/WHO Expert Committee on Food Additives, 2000), and estragole is carcinogenic and mutagenic at high doses (Committee on Herbal Medicinal Products, 2005).
The objectives of the present article are as follows: to describe the consumption of PFS containing fennel among a subsample of Finnish PFS consumers from the PlantLIBRA PFS Consumer Survey; to present the consumer reasons for PFS usage, perception of the usefulness of the products and the adverse effects experienced after usage; to describe the socio-demographic and lifestyle-related characteristics of the consumers; and to estimate the intake of selected bioactive compounds, including estragole and trans-anethole, from the fennel-containing PFS consumed by these Finnish consumers. To our knowledge, this article presents the first intake estimates of some of the bioactive compounds – namely trans-anethole, p-coumaric acid and rosmarinic acid – in human populations.
2. Materials and methods
2.1. PlantLIBRA PFS consumer survey
A cross-sectional 12-month retrospective PFS consumption survey was conducted in Finland and five other European countries. Before initiating the fieldwork, an ethical statement was obtained from the Coordinating Ethics Committee, Hospital District of Helsinki and Uusimaa, Finland. The details of the PlantLIBRA PFS Consumer Survey and its data collection procedures have been described elsewhere (Garcia-Alvarez et al., 2014). In this survey, the sample size in Finland was 401 PFS consumers. They came from four cities located in different parts of the country; Helsinki, Turku, Kuopio and Oulu. The gender and age group quotas were set as follows: 75% adults (18–59 years) and 25% elderly adults (60 years and over) with 50% males and 50% females.
The survey participants were regular PFS consumers, who were identified using a short screening questionnaire. The respondents were considered eligible for inclusion if they met either of the following specified criteria (Garcia-Alvarez et al., 2014):
- They had taken at least 1 PFS in the previous 12 months, in an appropriate dose form at a minimum frequency of:
- 1 daily dose for at least 2 consecutive or non-consecutive weeks, or
- 1 or more doses per week for at least 3 consecutive weeks, or
- 1 or more doses per week for at least 4 consecutive or non-consecutive weeks;
- They had taken 2 or more different PFS, in an appropriate dose form, at a minimum frequency of 1 or more doses per week, with the sum of the usage period for the 2 or more products being equal to at least 4 weeks.
Eligible consumers subsequently completed a more detailed questionnaire on their PFS usage habits in the preceding 12 months, providing details of plant and product names, dose forms, the frequency of use, reasons for use, adverse effects, places and patterns of purchase and information sources on products. These questions were asked for each of up to a maximum of five different PFS used. In addition, respondents were asked to provide socio-demographic data, including age, gender, the level of education and employment status, self-reported height and weight, and health-related lifestyle information.
Fieldwork and data collection for the PlantLIBRA cross-sectional survey were conducted by an international market research company, European Fieldwork Group, from May 2011 to September 2012. The duration of the fieldwork ensured that any seasonal variability in the usage of products was captured.
All data from the completed surveys were entered into the statistical package SPSS for Windows version 18 (IBM Corporation, Somers, NY, USA), which was also used for data analysis.