European Journal of Clinical Nutrition (2001) 55, 76±81 ß 2001 Nature Publishing Group All rights reserved 0954±3007/01 $15.00 www.nature.com/ejcn Catechin intake and associated dietary and lifestyle factors in a representative sample of Dutch men and women ICW Arts1,2*, PCH Hollman2, EJM Feskens1, HB Bueno de Mesquita1 and D Kromhout3 1National Institute of Public Health and the Environment (RIVM), Department of Chronic Diseases Epidemiology, Bilthoven, The Netherlands; 2State Institute for Quality Control of Agricultural Products (RIKILT), Wageningen, The Netherlands; and 3National Institute of Public Health and the Environment (RIVM), Division of Public Health Research, Bilthoven, The Netherlands Objective: To study the intake of catechins in the Dutch population and to assess the relation between catechin intake and other dietary factors. Catechins, dietary components that belong to the ¯avonoid family, potentially protect against chronic diseases such as cancer and cardiovascular diseases. Catechins are the major components of tea, but they are present in many other plant foods as well. Design: Data were used from a nationwide dietary survey carried out in 1998 among a representative sample of 6200 Dutch men and women aged 1 ± 97 y. Dietary data were collected using a 2 day dietary record method. Results: The average daily catechin intake was 50 mg (s.d. 56 mg=day). Catechin intake increased with age, and the intake was higher in women (60 mg=day) than in men (40 mg=day). Tea was the main catechin source in all age groups, whereas chocolate was second in children, and apples and pears were second in adults and elderly. Catechin intake was lower in smokers than in non-smokers, and increased with socio-economic status. A high intake was associated with a high intake of ®ber (r 0.20), vitamin C (r 0.17) and beta-carotene (r 0.10). Conclusions: Catechins are quantitatively important bioactive components of the daily diet, which should be taken into account when studying the relation between diet and chronic diseases. Catechin intake is only moderately associated with the intake of other nutrients, but much stronger with certain health behaviours such as smoking. Sponsorship: Commission of the European Communities Agriculture and Fisheries (FAIR) speci®c RTD Programme CT95 0653. Descriptors: catechin; tea; ¯avonoid; antioxidants; diet surveys; dietary intake European Journal of Clinical Nutrition (2001) 55, 76±81 Introduction species, induction of enzyme systems involved in detox- i®cation, and protection against DNA damaging free radi- Catechins, also referred to as ¯avanols, are one of the six cals through their antioxidant activity (Rice-Evans et al, subclasses of ¯avonoids. Flavonoids are non-nutritive sec- 1996; Middleton & Kandaswami, 1994). Catechins may ondary plant metabolites, which are common components help prevent low-density lipoprotein (LDL) from oxidative of the human diet. Currently more than 4000 different damage through their free radical quenching and metal ¯avonoids have been identi®ed (Harborne, 1994). In vitro chelating abilities (Wiseman et al, 1997; Rice-Evans et al, and in vivo animal experiments have shown that catechins 1996), or play a role in the in¯ammatory and thrombotic have antimutagenic and anticarcinogenic properties, and processes involved in atherosclerosis (Middleton, 1998; that they may play a role in the prevention of cardiovas- Wollny et al, 1999). cular diseases. Proposed mechanisms for these potential Catechins are the major components of tea; they con- human health promoting properties include inhibition of the stitute about 30% of the dry weight of green tea, and 9% of metabolic activation of procarcinogens to DNA-reactive the dry weight of black tea (Harbowy & Balentine, 1997). Epidemiological studies on health effects of tea have suggested that a high tea intake may protect against certain *Correspondence: ICWArts, RIVM, CZE, PO Box 1, 3720BA Bilthoven, The Netherlands cancers and coronary heart disease, but results are incon- E-mail: [email protected] sistent (Bushman, 1998; Kohlmeier et al, 1997; Tijburg et al, Guarantor: ICW Arts. 1997; Blot et al, 1996). On the other hand, there is ®rm Contributors: PH, EF and DK formulated the hypothesis, IA and PH evidence from experimental studies in laboratory animals collected part of the data, and all ®ve authors were involved in the analysis that tea may prevent chronic diseases (Katiyar & Mukhtar, of the data and the writing of the report. Received 11 April 2000; revised 11 September 2000; accepted 1996; Dreosti et al, 1997). One possible explanation for this 14 September 2000 apparent inconsistency is that tea is not the only catechin Catechin intake and associated factors ICW Arts et al 77 containing food in the human diet. In particular in countries Catechin intake calculation were tea intake is low, other foods may be more important The catechin intake for each individual was calculated by sources of catechins than tea. multiplying the consumption of each food by its catechin Recently, we reported data on catechin contents of a content. Catechin contents were estimated either by direct comprehensive set of foods and beverages (Arts et al, chemical analysis of the food concerned (37%), calculated 2000a, b). These data enable us to estimate the intake of using standard recipes if one or more ingredients contained these compounds in a population-based sample of men and catechins (57%), or derived from similar foods (6%). Data women in The Netherlands, and to study dietary and life- on catechin contents of several varieties of apples and pears style factors that are associated with a high intake of were combined into single values according to auction catechins. supply data. Similarly, data on catechin contents of tea blends, and white and red wines were combined into single values according to supply data provided by, respectively, the Coffee and Tea Information Bureau, and the Dutch Methods Commodity Board of Wine. Standard recipes were used to calculate the catechin contents of foods that contained Food consumption survey one or more chemically analyzed ingredients, except for The Dutch National Food Consumption Survey 1998 chocolate-containing foods, where data were derived from was carried out among a sample of households that was the Conversion Model Primary Agricultural Products (Van representative of the Dutch population. A household was Dooren-Flipsen et al, 1996). Because seasonal variation de®ned as one or more persons living together in one was relatively low (Arts et al, 2000a), year average cate- house, eating together a home-prepared hot meal for at chin values were used. Since catechins are predominantly least 4 days a week. Based on this de®nition, institutiona- present in foods that are usually consumed raw, eg fruit, lized persons were excluded. Also, subjects who had not catechin loss due to home preparation is not an important mastered the Dutch language suf®ciently, and children issue. younger than 1 y of age were excluded. A total of 6250 persons (2885 men and 3365 women) aged 1 ± 97 y coming Statistical analysis from 2564 households participated in the study. The Statistical analyses were performed using the SAS statis- response rate was 68.5%. Trained dieticians collected diet- tical package (SAS, release 6.12, SAS Institute, North ary data between April 1997 and March 1998 using a 2 day Carolina, USA). Pregnant women (n 50) were excluded dietary record method. No data were collected on holidays; from the analyses, because they tended to have a deviant otherwise, record-days were distributed equally over the 7 dietary pattern. Wilcoxon rank sum tests were used to days of the week and over the year. Other measurements compare mean catechin intakes between groups. Partial included age, height, weight, socio-economic status and rank-order correlation coef®cients were calculated between life-style variables such as smoking. As indicators of socio- total catechin intake and intake of alcohol, saturated and economic status, (former) occupation and attained educa- polyunsaturated fatty acids, ®ber, vitamin C, vitamin E, and tional level of the head of the household were used beta-carotene, after adjusting for total energy intake. Mean (Hulshof & Van Staveren, 1991; Voedingscentrum, 1998). intakes strati®ed by smoking status, and socio-economic status were standardized for age and sex using analysis of covariance. Children (< 19 y of age) were excluded from Food analysis the smoking status analysis. Six major catechins (( )-catechin, (7)-epicatechin, ( )- gallocatechin (GC), (7)-epigallocatechin (EGC), (7)- epicatechin gallate (ECg), and (7)-epigallocatechin Results gallate (EGCg)) were determined in a comprehensive set of plant foods by reversed-phase high performance liquid The mean intake of catechins in the total population was chromatography with online ultraviolet and ¯uorescence 50 mg=day (s.d. 56 mg=day), and ranged from 0 (284 detection (Arts & Hollman, 1998; Arts et al, 2000a, b). subjects, 4.6%) to 958 mg=day on the two particular days Analyzed foods included 24 types of fruits, 27 types of on which subjects were surveyed. The distribution of vegetables and legumes, some staple foods, and a number catechin intake in the adult population (19 y and older), of processed foods such as chocolate, eight types of black was strongly skewed towards higher values (Figure 1). tea, 18 types of red and white wine, fruit juices, ice-tea, Only 123 subjects (2% of the total population) had an beer, chocolate milk and coffee. All perishable foods were average intake on the two survey days that was higher than purchased at three outlets: a nationwide supermarket 200 mg=day. chain, an open-air street market, and a grocery. To take Of the individual catechins, ECg contributed most to the into account seasonal and year-to-year variability, fruits total catechin intake (33%), followed by EGCg (24%) and and vegetables were purchased in August and December (7)-epicatechin (23%). GC (5%), EGC (8%), and ( )- 1997 and in April and August 1998, if available in that catechin (8%) were minor contributors.