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Estimate of the maximal daily dietary intake of butylated hydroxyanisole and butylated hydroxytoluene in The Netherlands
Fd Chem. Toxic. Vol. 28, No. 4, pp. 215-220, 1990 Printed in Great Britain.All rights reserved
0278-6915/90 $3.00 + 0.00 Copyright © 1990Pergamon Press plc
Research Section ESTIMATE OF THE MAXIMAL DAILY DIETARY INTAKE OF BUTYLATED HYDROXYANISOLE A N D BUTYLATED H Y D R O X Y T O L U E N E IN THE N E T H E R L A N D S H. VERHAGEN*,I. DEERENBERG*,A. MARX, F. TEN HOOR*, P. TH. HENDERSON'[" and J. C. S. KLEINJANS* Departments of Human Biology* and Occupational and Environmental Health and Toxicologyt, University of Limburg, PO Box 616, 6200 MD Maastricht, The Netherlands (Received 4 April 1989; revisions received 23 November 1989)
Abstract--The daily dietary intake of the phenolic antioxidants butylated hydroxyanisole (BHA) and/or butylated hydroxytoluene (BHT) was estimated using data obtained from a nationwide dietary record survey carried out in The Netherlands in 1987/1988. The estimates were based on the fat content of selected food categories and their respective maximum permitted levels of BHA and/or BHT. The results indicate that it is unlikely that the current acceptable daily intake for BHA (0-0.5 mg/kg body weight) is surpassed, even in individuals with an extremely high caloric intake, except in extreme cases in l-6-year-olds. However, it cannot be excluded that the acceptable daily intake for BHT (FAO/WHO: 0-0.125 mg/kg; EEC: 0~.05 mg/kg) is exceeded in all age and sex groups, but particularly in children aged 1-6 years.
INTRODUCTION
Butylated hydroxyanisole (BHA; E320; CAS No. 25013-16-5) and butylated hydroxytoluene (BHT; E321; CAS No. 128-37-0) are synthetic phenolic antioxidants used widely to prevent oils, fats and shortenings from oxidative deterioration and rancidity (Sims and Fioriti, 1980). According to United States' concepts, these compounds are Generally Recognized As Safe (GRAS), as a result of their relatively low toxicity (Anonymous, 1984; IARC, 1986a). In addition, inhibitory activity in relation to carcinogenesis has been ascribed to BHA and BHT (Hocman, 1988; Wattenberg, 1985). Recently however, considerable concern has arisen about their use as food additives. In laboratory animals BHT and BHA are potent enhancers of mutagenesis and carcinogenesis induced by chemicals (Anonymous, 1984; IARC, 1986a,b; Ito et al., 1985; Ito and Hirose, 1987; JECFA, 1986a,b; Kahl, 1986; Kitchin and Brown, 1987; Witschi, 1986). Furthermore, in rodents there is evidence of the carcinogenicity of BHA in the forestomach (Clayson et al., 1986; Ito et al., 1985 and 1986; Ito and Hirose, 1987; Masui et al., 1986) and of BHT in the liver (Inai et al., 1988; Lindenschmidt et aL, 1986; Olsen et aL, 1986). Assessing the risk from human consumption of BHA and BHT is complicated by the fact that the mechanism of their carcinogenicity is not understood; neither compound exerts genotoxic activity (Hageman et al., 1988; IARC, 1986a,b). The F A O / W H O Joint Expert CornADI=acceptable daily intake; BHA= butylated hydroxyanisole; BHT = butylated hydroxytoluene; CIAA = Confederation des Industries AgroAlimentaires de la CEE; EEC = European Economic Community; GRAS = Generally Recognized As Safe; JECFA = Joint FAO/WHO Expert Committee on Food Additives.
Abbreviations:
FCT 28/4---A
mittee on Food Additives (JECFA) recently established temporary acceptable daily intakes (ADIs) of 0-0.5 mg BHA/kg body weight (JECFA, 1989) and 0-0.125mg BHT/kg (JECFA, 1986b). In addition, the Scientific Committee for Food of the Commission of the European Communities also set an ADI of 0-0.5mg/kg for BHA but only 0-0.05mg/kg for BHT (Anonymous, 1987; Haigh, 1986). Accurate data on the daily intakes of BHA and/or BHT by man are not available. Estimates range from 0.05 to 3 mg/person/day (FASEB, 1978) to 0.5 to 1.5 mg/kg body weight/day (Malkinson, 1983), but are generally in the range of 1 to 1.15 rag/person/day (Anonymous, 1986a,b; CIAA, 1985; Collings and Sharratt, 1970; Kahl, 1986; Kangsadalampai et aL, 1986; Kirkpatrick and Lauer, 1986). However, most estimates are based either on confidential data or on reports that are not readily available. Only Kirkpatrick and Lauer (1986) gave a clear insight into the data on which their assessment of phenolic antioxidant intake in Canada and the USA in the 1970s was founded. This study sets out to estimate quantitatively ageand sex-related daily dietary intakes of BHA and/or BHT in The Netherlands. The estimates are based on the fat content of seven out of 23 selected food categories. It was assumed that all of the fat consumed contained maximal permitted levels of antioxidants, and that these antioxidants were BHA and/or BHT. Risk assessment for BHA and BHT was made by comparing the estimated BHA and/or BHT intakes with the current ADIs for these food additives. MATERIALS AND METHODS
The potential dietary BHA and/or BHT intake in The Netherlands was calculated using data from
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a nationwide dietary record survey (Anonymous, 1988), as proposed by the Dutch Nutritional Council in 1986. This survey, funded by the Dutch ministries of Welfare, Health and Cultural Affairs, and of Agriculture and Fisheries, was carried out in 1987/1988, and included 2204 households, with a total of 5898 participants representing the Dutch population within the age range 1 to 75 years. Participants recorded their consumption of food and drinks for two consecutive days. Collection of data was uniformly spread over the seven days of the week and the four seasons. No data were collected during holidays and vacation periods. Of the 23 distinct food categories, seven that might possibly contain BHA and/or BHT were selected (Table 1). For this selection the only foods included were those that require protection by antioxidants (CIAA, 1985; Haigh, 1986); foods to which addition of BHA and/or BHT is not permitted by Dutch legislation were excluded. Estimates of dietary BHA and/or BHT intake were based on the consumption of fat in these selected food categories. It was assumed that all fat consumed contained the maximal levels of antioxidants permitted according to Dutch legislation, and that these antioxidants were BHA and/or BHT (Table 2). Thus, by this maximal approach BHA and/or BHT intake was calculated, using data on average fat consumption, according to the equation: 7
BHA and/or BHT intake = ~ FfcMLfc fc=l
wherefc stands for the selected food categories (1-7), F is the average fat consumption from the selected food category and ML is the maximally permitted level of BHA and/or BHT in the fat. Food category 3 was further differentiated. Since addition of BHA and/or BHT to butter and margarine is not allowed, the fat intake from these items was omitted from the calculations. Since the fat content of 'emulsified Table 1. Food categories distinguished in the nationwide dietary record survey in The Netherlands in 1987/I988* Category no. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Table 2. Maximum permitted levels of BHA and BHT in food in The Netherlands*
Food product
Maximum permitted level of BHA and/or BHTt (mg/kg food)
Oils and fats~: Biscuits Soup Flavours Etherial oils
100 400~ 100~ 200 1000
*Adapted in part from Staarink and Hakkenbrak (1985). tAlone or in combination with other antioxidants. .~With the exception of margarine and (cacao) butter. §Based on the fat content.
sauces' was not specified, it was, somewhat arbitrarily, set at 25%, a 'common' fat content of emulsified sauces in The Netherlands. No distinction could be made between BHA and BHT, so all data are referred to as 'BHA and/or BHT'. Therefore, 'BHA and/or BHT' may be interpreted as either exclusively BHA, or exclusively BHT, or an unknown ratio of BHA and BHT. Since average body weight is related to age, the estimated daily BHA and/or BHT consumption is expressed on a dose/body weight basis, using average age-related body weights as reported by Chenauit (1984). Furthermore, we attempted to differentiate between subjects with higher or lower fat intakes, which would result in higher or lower estimated BHA and/or BHT intakes. Only descriptive statistical data were available on variations in fat consumption for each of the selected food categories separately. There were no data on variations in fat intake, and consequently in the estimated maximal BHA and/or BHT intake, from a combination of the seven selected food categories. Therefore, the inter-individual variation in total fat consumption (i.e. over all 23 food categories) was taken as the possible inter-individual variation in BHA and/or BHT intake. By this method the mean, median, minimal and maximal daily dietary BHA and/or BHT intakes as well as the standard deviation of these estimates were calculated.
Food category Potatoes and tuberous plantst Cereals and cereal productst Fats, oils, mayonnaise etc.t Soup~" Pastry, cake and biscuitst Sugar, sweets and sweetspreads~" Nuts, seeds and snackst Vegetables Pulses Fruit Bread Milk and milk products Cheese Eggs Meat, meat products and poultry Fish and shellfish Composed dishes Peanut butter, spreads etc. Non-alcoholic beverages Alcoholic beverages Herbs and spices Preparations Miscellaneous
*Adapted in part from Anonymous (1988). tlt was considered possible that these categories might contain BHA and/or BHT.
RESULTS
Table 3 gives an example of the calculation of the average BHA and/or BHT consumption for all ages Table 3. Average BHA aod/or BHT intakes from different food categories
Category* 1
2 3:~ 4 5 6 7
Average fat consumption (g/day/person)t
Maximum permitted level of BHA and/or BHT (%)
2.0 0.4 2.2 1.6 7.2 2.9 7.2
0.01 0.01 0.01 0.01 0.04 0.01 0.01
Maximal possible intake of BHA and/or BHT (rag/day/person) 0.2 0.04 0.22 0.16 2.88 0.29 0.72 4.51 mg
*See Table I. tData for 5898 individuals were included. $Corrections have already been made for the consumption of margarine and butter, which are not allowed to contain BHA and BHT. Actual fat consumption in this category was 33.5 g,
Intake of BHA and BHT by man
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(o) 0.6"
A
==
ADI for 8HA (FA0/WHO; EECI
0.5"
0.4" -r m
•
FemaLes
[]
MaLes
•
FemaLes/maLes
3: rn
AOI for BHT(FAO/WHO) AOI for BHT (EEC)
1-3
4-6
?-9
10-15 16-21 22-49 50-64
65t-
aU.
Age groups (yr) (b) 0.6-
_ •0.5
A OI for BHA ( FAO/ WHO ; EEC)
0.4 "r rn "~
$
0.3
o.z ADI f~" BHT(FAO/WHO)
~
0.1
ADI for BHT(EEC)
I-3
4-6
7-9
10-15 16-21 2 2 - 4 9 5 0 - 6 4
65"1"
0LL
Age groups ( yr )
Fig. 1. Estimated daily intake of BHA and/or BHT from food in The Netherlands, subdivided into age groups and sexes. The data represent a maximal approach, based on the assumption that all food products, in which these additives are allowed, contain maximally permitted levels of BHA and/or BHT. (a) Mean (+SD) BHA and/or BHT intake; (b) estimated maximal intake of BHA and/or BHT. The lower range is not indicated but is close to zero in all instances. No distinction between the sexes was made in the age groups 1-3, 4q5 and 7-9 years. For comparison, the present established ADIs for BHA (0.5 mg/kg) and BHT (0-0.125 and 0-0.05 mg/kg) are indicated. (n = 5898) based on the fat content of seven out of 23 selected food categories (from Table 1), their respective maximum permitted BHA and/or BHT levels and the consumption of fat from these food categories. The highest contribution to the consumption of BHA and/or BHT is made by pastries, cakes and biscuits (category 5) in all age and sex groups. On average, based on this maximal approach, BHA and/or BHT intake is 4.51mg/day or 0.075 mg/kg body weight/day for a 60-kg individual. Estimates for all the different age and sex groups range from 2.31 mg/day in children aged 1-3 years to 5.76mg/day in male adolescents (16-21 years). Figure I summarizes the results of the maximal approach on dietary BHA and/or BHT intake for all classes of Dutch inhabitants expressed on a
dose/body weight basis. Figure la shows the average BHA and/or BHT intakes and includes the standard deviation of the estimates; Fig. lb shows estimated maximum intakes. Minimal intakes were, as a rule, close to zero (data not shown). Median fat (and consequently BHA and/or BHT) intake was 95.3 + 1.2% of mean fat intake, as has been calculated for all age and sex groups. The estimated BHA and/or BHT intake was significantly higher in females compared with males for the age groups 10-15, 22--49 and 50--64 years (P <0.001) and the age group 65 + years (P < 0.02; Student's t-test for unpaired values). The current ADIs (0--0.5 mg/kg body weight for BHA and 0-0.125 and 0--0.05 mg/kg for BHT; Anonymous, 1987; Haigh, 1986; JECFA, 1986b and 1989) are included for comparison. The results of this
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maximal approach indicate that if BHA and/or BHT intake represented exclusively consumption of BHA, only in children, aged 1-6 years, is it possible that the ADI may be surpassed. However, if intake were exclusively BHT, it is quite possible that the present ADIs for BHT could be exceeded in all age and sex groups. In particular, younger children may ingest an amount of BHT that is about ten times the lowest ADI set for BHT (0-0.05 mg/kg). DISCUSSION
There is considerable evidence of the carcinogenicity of BHA and BHT in laboratory animals (Clayson et al., 1986; Inai et al., 1988; Ito et al., 1985 and 1986; Ito and Hirose, 1987; Lindenschmidt et al., 1986; Masui et al., 1986; Olsen et al., 1986). Both food antioxidants, although complete carcinogens, are thought to exert their tumorigenicity by nongenotoxic mechanisms (Hageman et al., 1988; IARC, 1986a,b). Therefore the current ADIs for BHA and BHT are based on the approach of determining a no-effect level and applying safety factors (Anonymous, 1987; JECFA, 1986b and 1989; Haigh, 1986), taking tumorigenicity-related changes into account. In the present study, risk assessment for BHA and BHT was performed by comparing the estimated BHA and/or BHT intake by man in The Netherlands, based on a maximal approach, with the ADIs of these food additives. The results indicate that it is unlikely that the current ADI for BHA (0-0.5 mg/kg body weight/day) is exceeded, except in extreme cases in l-6-year-oids, but also that it cannot be excluded that the ADI for BHT (0-0.125 mg/kg and 0-0.05 mg/kg) is surpassed at all ages and in both sexes. Several methods of assessing dietary BHA and/or BHT intake have been reported. Van Dokkum et al. (1982) performed a market-basket study followed by chemical analysis of homogenized foods, and detected BHA, but not BHT, in the food category 'fish', although in a limited number of samples only. They concluded that maximal BHA intake by male adolescents in The Netherlands was 4 mg/person/day, which is in line with the present results. However, because of dilution of BHA and/or BHT in the homogenization procedure this method has the disadvantage of rather a high detection limit. The BHA and/or BHT intake may alternatively be estimated from the amount of antioxidants sold to manufacturers (CIAA, 1985; Rehwoldt, 1986). However, these data are frequently confidential and therefore not regularly available. From such confidential data, the CIAA (1985) estimated a daily average intake of 1 mg/person in adults in countries of the EEC for all food antioxidants together (i.e. BHA, BHT, gallates, tecopherols and ascorbyl palmitate), increasing to 3 mg/person for individuals with largely aberrant dietary habits. Another method is based on the consumption of fat by man and the maximal BHA and/or BHT content of fats, possibly corrected for the consumption of fat from foods in which BHA and BHT are not allowed. Most reports estimating the daily dietary BHA and/or BHT intake by man are based on this methodology (CIAA, 1985; Kirkpatrick and Lauer, 1986). Daily dietary fat consumption has either been
estimated from the percentage of caloric intake taken as fat (CIAA, 1985) or by a dietary recall survey (Kirkpatrick and Lauer, 1986). The CIAA (1985) estimated a maximal total antioxidant intake of 14mg/person/day for adults in EEC countries. Kirkpatrick and Lauer (1986) estimated that the dietary intake of BHA and other permitted phenolic antioxidants (BHT and propyl gallate) was unlikely to exceed 1 mg/kg/day and on average was less than 0.4mg/kg/day. Although Kirkpatrick and Lauer (1986) indicated that younger children constitute a potential risk group for dietary BHA and/or BHT intake, which is in line with the present study, their report is not applicable to the Dutch situation, since there is a legal difference in the permitted use of BHA and/or BHT in Canada and the USA, and feeding patterns are different in these countries from those in The Netherlands. For instance, the main contribution to BHA and/or BHT intake in the study of Kirkpatrick and Lauer (1986) is made by cereals, a food group that is not consumed so much in The Netherlands as in Canada or the USA. Moreover, BHA and BHT may be found in bread in Canada and the USA as a result of carryover from the fats and oils used to prepare this food, and this is not a possibility in The Netherlands. By contrast with the method of Kirkpatrick and Lauer (1986), in the present report the estimated BHA and/or BHT intake in The Netherlands was based on a 2-day dietary record survey, including all age groups and both sexes. It is emphasized that the present estimates of BHA and/or BHT intake were based on a maximal approach assuming that all of the fat in the food categories included contained maximally permitted levels of antioxidants, according to Dutch legislation, and that these antioxidants were BHA and/or BHT. The estimates accounted neither for losses of BHA and/or BHT during food storage or processing nor for lower levels of BHA and/or BHT in food products as a result of intentional limited use by the manufacturer nor for the addition of other antioxidants (e.g. tocopherols, gallate esters, etc.; Sims and Fioriti, 1980). Reported values may also have been over-estimated as some food categories (e.g. category 6) might have comprised food items that are not allowed to contain BHA and/or BHT (e.g. chocolate). Consequently, actual BHA and/or BHT intakes may be lower than the estimated levels of intake. However, these over-estimates are counter-balanced to some extent by the fact that not all food products that might contain BHA and/or BHT have been included in the selected food categories. It is conceivable that food products in categories 15, 16, 17 and 18 also occasionally contain BHA and/or BHT. In addition, the migration of BHA and BHT from packaging materials, especially those that are waxed, into foods may also contribute to a higher BHA and/or BHT intake by man (Anonymous, 1986a,b; Bieber et al., 1984; Schroeder, 1973; Sims and Fioriti, 1980). Thus, although the applied methodology may have advantages compared with other reported methods, several factors may have given rise to aberrant estimates of the actual daily BHA and/or BHT consumption in The Netherlands. If the estimated maximal antioxidant intake were exclusively BHA, the results indicate that the
Intake of BHA and BHT by man daily dietary consumption of BHA by man in The Netherlands is unlikely to exceed the ADI for this agent, except in extreme cases in l-6-year-olds. Therefore, its application as a food additive should be considered safe. However, it has previously been shown that oral administration of the ADI for BHA (0.5 mg/kg) to man and a 400 times higher dose to the rat (200 mg/kg) resulted in plasma BHA levels within one order of magnitude (Verhagen et al., 1989), which indicates that the current ADI for BHA might not be sufficient to protect man from the possible adverse effects associated with dietary BHA consumption. The ADI for BHA is based on a no-effect level of 62.5 mg/kg body weight for the induction of proliferative changes in the rat forestomach (JECFA, 1986a), which indicates that a toxic effect of BHA in man would probably involve a proliferative effect. If the estimated maximal antioxidant intake were exclusively BHT, it cannot be excluded that the ADIs for BHT might be exceeded in all age and sex groups. Our results raise possible concern about the application of BHT as an additive to human food. Therefore, further research on the actual daily intake of BHT by man is needed. Specifically, the blood coagulation system would probably be the target of BHT toxicity in man, since the lowest ADI for BHT (0-0.05 mg/kg) is based on a no-effect level for (transient) haemorrhagic effects following administration of about 5 mg BHT/kg body weight in a short-term experiment with rats (Anonymous, 1987). In conclusion, based on a maximal approach, it is unlikely that the estimated average daily dietary intake of BHA by man in The Netherlands will exceed the ADI, except in extreme cases in l-6-yearolds. However, it cannot be excluded that the ADI for BHT is exceeded in all age and sex groups. As a result of the high potential consumption of BHT, younger children form a risk group for the toxic effects of BHT. REFERENCES
Anonymous (1984) Final Report of the Safety Assessment for BHA. J. Am. Coll. Toxicol. 3, 83-146. Anonymous (1987) Report of the ScientificCommittee for Food of the Commission of the European Communities on Antioxidants. CS/ANT/20-Final. Anonymous (1988) Wat eet Nederland. Resultaten van de voedselconsumptiepeiling 1987-1988. Ministerie van Welzijn, Volksgezondheid en Cultuur en Ministerie van Landbouw en Visserij (in Dutch; summary in English). Bieber W.-D., Freytag W., Figge K., vom Bruck C. G. and Rossi L. (1984) Transfer of additives from plastic materials into foodstuffs and into food simulants--a comparison. Fd Chem. Toxic. 22, 737-742. Chenault A. A. (1984) Nutrition and Health. CBS College Publishing Hold, Rinehart and Winston, New York. CIAA (Confederation des industries agro-alimentaires de la CEE) (1985) Antioxidants. A dossier prepared by the CIAA for submission to the EEC ScientificCommittee for Food. ADD-8/85-Final. Clayson D. B., Iverson F., Nera E., Lok E., Rogers C., Rodrigues C., Page D. and Karpinski K. (1986) Histopathological and autoradiographical studies on the forestomach of F344 rats treated with butylated hydroxyanisole and related chemicals. Fd Chem. Toxic. 24, 1171-1182. Collings A. J. and Sharratt M. (1970) The BHT content of human adipose tissue. Fd Cosmet. Toxicol. 8, 409-412.
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FASEB (1978) Evaluation of the health aspects of butylated hydroxyanisole as a food ingredient; cited from Anonymous (1984). Hageman G. J., Verhagen H. and Kleinjans J. C. S. (1988) Butylated hydroxyanisole, butylated hydroxytoluene, and tert-butylhydroquinone are not mutagenic in the Salmonella/microsome assay using new tester strains. Mutation Res. 208, 207-211. Haigh R. (1986) Safety and necessity of antioxidants: EEC approach. Fd Chem. Toxic. 24, 1031-1034. Hocman G. (1988) Chemoprevention of cancer: phenolic antioxidants (BHT, BHA). Int. J. Biochem. 7, 639--651. IARC Working Group (1986a) Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans.
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Vol. 40, pp. 161-206. International Agency for Research on Cancer, Lyon. Inai K., Kobuke T., Nambu S., Takemoto T., Kou E., Nishina H., Fulihara M., Yonehara S., Suehiro S., Tsuya T., Horiuchi K. and Tokuoka S. (1988) Hepatocellular tumorigenicity of butylated hydroxytoluene administered orally to B6C3F1 mice. Gann 79, 49-58. Ito N., Fukushima S., Tamano S., Hirose M. and Hagiwara A. (1986) Dose response in butylated hydroxyanisole induction of forestomach carcinogenesis in F344 rats. J. natn. Cancer Inst. 77, 1261-1265. Ito N., Fukushima S. and Tsuda H. (1985) Carcinogenicity and modification of the carcinogenic response by BHA, BHT and other antioxidants. CRC Crit. Rev. Toxicol. 15, 109-150. Ito N. and Hirose M. (1987) The role of antioxidants in chemical carcinogenesis. Gann 78, 1011-1026. Joint FAO/WHO Expert Committee on Food Additives (1986a) Toxicological Evaluation of Certain Food Additives and Contaminants. Butylated Hydroxyanisole (BHA). WHO Fd Add. Ser. 21, 3-24. Joint FAO/WHO Expert Committee on Food Additives (1986b) Toxicological Evaluation of Certain Food Additives and Contaminants. Butylated Hydroxytoluene (BHT). W H O Fd Add. Ser. 21, 25-46. Joint FAO/WHO Expert Committee on Food Additives (1989) Evaluation of Certain Food Additives and Contaminants. WHO Tech. Rep. Ser. no. 776, 14--15. Kahl R. (1986) The dual role of antioxidants in the modification of chemical carcinogenesis.3". envir. Sci. Hlth C4, 47-92. Kangsadalampai K., Sharma R. P., Taylor M. J. and Salunkhe D. K. (1986) Effect of protein deficiency and Tween 60 on the pharmacokinetics of butylated hydroxyanisole and metabolites in male Sprague--Dawley rats. Drug-Nutrient Interact. 4, 289-297. Kirkpatrick D. C. and Lauer B. H. (1986) Intake of phenolic antioxidants from foods in Canada. Fd Chem. Toxic. 24, 1035-1037. Kitchin K. T. and Brown J. L. (1987) Biochemicaleffects of two promotors of hepatocarcinogenesis in rats. Fd Chem. Toxic. 25, 603-607. Lindenschmidt R. C., Tryka A. F., Good M. E. and Witschi H. P. (1986) The effects of dietary butylated hydroxytoluene on liver and colon tumor development in mice. Toxicology 38, 151-160. Malkinson A. M. (1983) Review: putative mutagens and carcinogens in foods. III. Butylated hydroxytoluene (BHT). Envir. Mutagen. 5, 353-362. Masui T., Hirose M., Imaida K., Fukushima S., Tamano S. and Ito N. (1986) Sequential changes of the forestomach of F344 rats, Syrian golden hamsters, and B6C3F1 mice treated with butylated hydroxyanisole. Gann 77, 1083-1090.
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0278-6915/90 $3.00 + 0.00 Copyright © 1990Pergamon Press plc
Research Section ESTIMATE OF THE MAXIMAL DAILY DIETARY INTAKE OF BUTYLATED HYDROXYANISOLE A N D BUTYLATED H Y D R O X Y T O L U E N E IN THE N E T H E R L A N D S H. VERHAGEN*,I. DEERENBERG*,A. MARX, F. TEN HOOR*, P. TH. HENDERSON'[" and J. C. S. KLEINJANS* Departments of Human Biology* and Occupational and Environmental Health and Toxicologyt, University of Limburg, PO Box 616, 6200 MD Maastricht, The Netherlands (Received 4 April 1989; revisions received 23 November 1989)
Abstract--The daily dietary intake of the phenolic antioxidants butylated hydroxyanisole (BHA) and/or butylated hydroxytoluene (BHT) was estimated using data obtained from a nationwide dietary record survey carried out in The Netherlands in 1987/1988. The estimates were based on the fat content of selected food categories and their respective maximum permitted levels of BHA and/or BHT. The results indicate that it is unlikely that the current acceptable daily intake for BHA (0-0.5 mg/kg body weight) is surpassed, even in individuals with an extremely high caloric intake, except in extreme cases in l-6-year-olds. However, it cannot be excluded that the acceptable daily intake for BHT (FAO/WHO: 0-0.125 mg/kg; EEC: 0~.05 mg/kg) is exceeded in all age and sex groups, but particularly in children aged 1-6 years.
INTRODUCTION
Butylated hydroxyanisole (BHA; E320; CAS No. 25013-16-5) and butylated hydroxytoluene (BHT; E321; CAS No. 128-37-0) are synthetic phenolic antioxidants used widely to prevent oils, fats and shortenings from oxidative deterioration and rancidity (Sims and Fioriti, 1980). According to United States' concepts, these compounds are Generally Recognized As Safe (GRAS), as a result of their relatively low toxicity (Anonymous, 1984; IARC, 1986a). In addition, inhibitory activity in relation to carcinogenesis has been ascribed to BHA and BHT (Hocman, 1988; Wattenberg, 1985). Recently however, considerable concern has arisen about their use as food additives. In laboratory animals BHT and BHA are potent enhancers of mutagenesis and carcinogenesis induced by chemicals (Anonymous, 1984; IARC, 1986a,b; Ito et al., 1985; Ito and Hirose, 1987; JECFA, 1986a,b; Kahl, 1986; Kitchin and Brown, 1987; Witschi, 1986). Furthermore, in rodents there is evidence of the carcinogenicity of BHA in the forestomach (Clayson et al., 1986; Ito et al., 1985 and 1986; Ito and Hirose, 1987; Masui et al., 1986) and of BHT in the liver (Inai et al., 1988; Lindenschmidt et aL, 1986; Olsen et aL, 1986). Assessing the risk from human consumption of BHA and BHT is complicated by the fact that the mechanism of their carcinogenicity is not understood; neither compound exerts genotoxic activity (Hageman et al., 1988; IARC, 1986a,b). The F A O / W H O Joint Expert CornADI=acceptable daily intake; BHA= butylated hydroxyanisole; BHT = butylated hydroxytoluene; CIAA = Confederation des Industries AgroAlimentaires de la CEE; EEC = European Economic Community; GRAS = Generally Recognized As Safe; JECFA = Joint FAO/WHO Expert Committee on Food Additives.
Abbreviations:
FCT 28/4---A
mittee on Food Additives (JECFA) recently established temporary acceptable daily intakes (ADIs) of 0-0.5 mg BHA/kg body weight (JECFA, 1989) and 0-0.125mg BHT/kg (JECFA, 1986b). In addition, the Scientific Committee for Food of the Commission of the European Communities also set an ADI of 0-0.5mg/kg for BHA but only 0-0.05mg/kg for BHT (Anonymous, 1987; Haigh, 1986). Accurate data on the daily intakes of BHA and/or BHT by man are not available. Estimates range from 0.05 to 3 mg/person/day (FASEB, 1978) to 0.5 to 1.5 mg/kg body weight/day (Malkinson, 1983), but are generally in the range of 1 to 1.15 rag/person/day (Anonymous, 1986a,b; CIAA, 1985; Collings and Sharratt, 1970; Kahl, 1986; Kangsadalampai et aL, 1986; Kirkpatrick and Lauer, 1986). However, most estimates are based either on confidential data or on reports that are not readily available. Only Kirkpatrick and Lauer (1986) gave a clear insight into the data on which their assessment of phenolic antioxidant intake in Canada and the USA in the 1970s was founded. This study sets out to estimate quantitatively ageand sex-related daily dietary intakes of BHA and/or BHT in The Netherlands. The estimates are based on the fat content of seven out of 23 selected food categories. It was assumed that all of the fat consumed contained maximal permitted levels of antioxidants, and that these antioxidants were BHA and/or BHT. Risk assessment for BHA and BHT was made by comparing the estimated BHA and/or BHT intakes with the current ADIs for these food additives. MATERIALS AND METHODS
The potential dietary BHA and/or BHT intake in The Netherlands was calculated using data from
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a nationwide dietary record survey (Anonymous, 1988), as proposed by the Dutch Nutritional Council in 1986. This survey, funded by the Dutch ministries of Welfare, Health and Cultural Affairs, and of Agriculture and Fisheries, was carried out in 1987/1988, and included 2204 households, with a total of 5898 participants representing the Dutch population within the age range 1 to 75 years. Participants recorded their consumption of food and drinks for two consecutive days. Collection of data was uniformly spread over the seven days of the week and the four seasons. No data were collected during holidays and vacation periods. Of the 23 distinct food categories, seven that might possibly contain BHA and/or BHT were selected (Table 1). For this selection the only foods included were those that require protection by antioxidants (CIAA, 1985; Haigh, 1986); foods to which addition of BHA and/or BHT is not permitted by Dutch legislation were excluded. Estimates of dietary BHA and/or BHT intake were based on the consumption of fat in these selected food categories. It was assumed that all fat consumed contained the maximal levels of antioxidants permitted according to Dutch legislation, and that these antioxidants were BHA and/or BHT (Table 2). Thus, by this maximal approach BHA and/or BHT intake was calculated, using data on average fat consumption, according to the equation: 7
BHA and/or BHT intake = ~ FfcMLfc fc=l
wherefc stands for the selected food categories (1-7), F is the average fat consumption from the selected food category and ML is the maximally permitted level of BHA and/or BHT in the fat. Food category 3 was further differentiated. Since addition of BHA and/or BHT to butter and margarine is not allowed, the fat intake from these items was omitted from the calculations. Since the fat content of 'emulsified Table 1. Food categories distinguished in the nationwide dietary record survey in The Netherlands in 1987/I988* Category no. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Table 2. Maximum permitted levels of BHA and BHT in food in The Netherlands*
Food product
Maximum permitted level of BHA and/or BHTt (mg/kg food)
Oils and fats~: Biscuits Soup Flavours Etherial oils
100 400~ 100~ 200 1000
*Adapted in part from Staarink and Hakkenbrak (1985). tAlone or in combination with other antioxidants. .~With the exception of margarine and (cacao) butter. §Based on the fat content.
sauces' was not specified, it was, somewhat arbitrarily, set at 25%, a 'common' fat content of emulsified sauces in The Netherlands. No distinction could be made between BHA and BHT, so all data are referred to as 'BHA and/or BHT'. Therefore, 'BHA and/or BHT' may be interpreted as either exclusively BHA, or exclusively BHT, or an unknown ratio of BHA and BHT. Since average body weight is related to age, the estimated daily BHA and/or BHT consumption is expressed on a dose/body weight basis, using average age-related body weights as reported by Chenauit (1984). Furthermore, we attempted to differentiate between subjects with higher or lower fat intakes, which would result in higher or lower estimated BHA and/or BHT intakes. Only descriptive statistical data were available on variations in fat consumption for each of the selected food categories separately. There were no data on variations in fat intake, and consequently in the estimated maximal BHA and/or BHT intake, from a combination of the seven selected food categories. Therefore, the inter-individual variation in total fat consumption (i.e. over all 23 food categories) was taken as the possible inter-individual variation in BHA and/or BHT intake. By this method the mean, median, minimal and maximal daily dietary BHA and/or BHT intakes as well as the standard deviation of these estimates were calculated.
Food category Potatoes and tuberous plantst Cereals and cereal productst Fats, oils, mayonnaise etc.t Soup~" Pastry, cake and biscuitst Sugar, sweets and sweetspreads~" Nuts, seeds and snackst Vegetables Pulses Fruit Bread Milk and milk products Cheese Eggs Meat, meat products and poultry Fish and shellfish Composed dishes Peanut butter, spreads etc. Non-alcoholic beverages Alcoholic beverages Herbs and spices Preparations Miscellaneous
*Adapted in part from Anonymous (1988). tlt was considered possible that these categories might contain BHA and/or BHT.
RESULTS
Table 3 gives an example of the calculation of the average BHA and/or BHT consumption for all ages Table 3. Average BHA aod/or BHT intakes from different food categories
Category* 1
2 3:~ 4 5 6 7
Average fat consumption (g/day/person)t
Maximum permitted level of BHA and/or BHT (%)
2.0 0.4 2.2 1.6 7.2 2.9 7.2
0.01 0.01 0.01 0.01 0.04 0.01 0.01
Maximal possible intake of BHA and/or BHT (rag/day/person) 0.2 0.04 0.22 0.16 2.88 0.29 0.72 4.51 mg
*See Table I. tData for 5898 individuals were included. $Corrections have already been made for the consumption of margarine and butter, which are not allowed to contain BHA and BHT. Actual fat consumption in this category was 33.5 g,
Intake of BHA and BHT by man
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(o) 0.6"
A
==
ADI for 8HA (FA0/WHO; EECI
0.5"
0.4" -r m
•
FemaLes
[]
MaLes
•
FemaLes/maLes
3: rn
AOI for BHT(FAO/WHO) AOI for BHT (EEC)
1-3
4-6
?-9
10-15 16-21 22-49 50-64
65t-
aU.
Age groups (yr) (b) 0.6-
_ •0.5
A OI for BHA ( FAO/ WHO ; EEC)
0.4 "r rn "~
$
0.3
o.z ADI f~" BHT(FAO/WHO)
~
0.1
ADI for BHT(EEC)
I-3
4-6
7-9
10-15 16-21 2 2 - 4 9 5 0 - 6 4
65"1"
0LL
Age groups ( yr )
Fig. 1. Estimated daily intake of BHA and/or BHT from food in The Netherlands, subdivided into age groups and sexes. The data represent a maximal approach, based on the assumption that all food products, in which these additives are allowed, contain maximally permitted levels of BHA and/or BHT. (a) Mean (+SD) BHA and/or BHT intake; (b) estimated maximal intake of BHA and/or BHT. The lower range is not indicated but is close to zero in all instances. No distinction between the sexes was made in the age groups 1-3, 4q5 and 7-9 years. For comparison, the present established ADIs for BHA (0.5 mg/kg) and BHT (0-0.125 and 0-0.05 mg/kg) are indicated. (n = 5898) based on the fat content of seven out of 23 selected food categories (from Table 1), their respective maximum permitted BHA and/or BHT levels and the consumption of fat from these food categories. The highest contribution to the consumption of BHA and/or BHT is made by pastries, cakes and biscuits (category 5) in all age and sex groups. On average, based on this maximal approach, BHA and/or BHT intake is 4.51mg/day or 0.075 mg/kg body weight/day for a 60-kg individual. Estimates for all the different age and sex groups range from 2.31 mg/day in children aged 1-3 years to 5.76mg/day in male adolescents (16-21 years). Figure I summarizes the results of the maximal approach on dietary BHA and/or BHT intake for all classes of Dutch inhabitants expressed on a
dose/body weight basis. Figure la shows the average BHA and/or BHT intakes and includes the standard deviation of the estimates; Fig. lb shows estimated maximum intakes. Minimal intakes were, as a rule, close to zero (data not shown). Median fat (and consequently BHA and/or BHT) intake was 95.3 + 1.2% of mean fat intake, as has been calculated for all age and sex groups. The estimated BHA and/or BHT intake was significantly higher in females compared with males for the age groups 10-15, 22--49 and 50--64 years (P <0.001) and the age group 65 + years (P < 0.02; Student's t-test for unpaired values). The current ADIs (0--0.5 mg/kg body weight for BHA and 0-0.125 and 0--0.05 mg/kg for BHT; Anonymous, 1987; Haigh, 1986; JECFA, 1986b and 1989) are included for comparison. The results of this
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maximal approach indicate that if BHA and/or BHT intake represented exclusively consumption of BHA, only in children, aged 1-6 years, is it possible that the ADI may be surpassed. However, if intake were exclusively BHT, it is quite possible that the present ADIs for BHT could be exceeded in all age and sex groups. In particular, younger children may ingest an amount of BHT that is about ten times the lowest ADI set for BHT (0-0.05 mg/kg). DISCUSSION
There is considerable evidence of the carcinogenicity of BHA and BHT in laboratory animals (Clayson et al., 1986; Inai et al., 1988; Ito et al., 1985 and 1986; Ito and Hirose, 1987; Lindenschmidt et al., 1986; Masui et al., 1986; Olsen et al., 1986). Both food antioxidants, although complete carcinogens, are thought to exert their tumorigenicity by nongenotoxic mechanisms (Hageman et al., 1988; IARC, 1986a,b). Therefore the current ADIs for BHA and BHT are based on the approach of determining a no-effect level and applying safety factors (Anonymous, 1987; JECFA, 1986b and 1989; Haigh, 1986), taking tumorigenicity-related changes into account. In the present study, risk assessment for BHA and BHT was performed by comparing the estimated BHA and/or BHT intake by man in The Netherlands, based on a maximal approach, with the ADIs of these food additives. The results indicate that it is unlikely that the current ADI for BHA (0-0.5 mg/kg body weight/day) is exceeded, except in extreme cases in l-6-year-oids, but also that it cannot be excluded that the ADI for BHT (0-0.125 mg/kg and 0-0.05 mg/kg) is surpassed at all ages and in both sexes. Several methods of assessing dietary BHA and/or BHT intake have been reported. Van Dokkum et al. (1982) performed a market-basket study followed by chemical analysis of homogenized foods, and detected BHA, but not BHT, in the food category 'fish', although in a limited number of samples only. They concluded that maximal BHA intake by male adolescents in The Netherlands was 4 mg/person/day, which is in line with the present results. However, because of dilution of BHA and/or BHT in the homogenization procedure this method has the disadvantage of rather a high detection limit. The BHA and/or BHT intake may alternatively be estimated from the amount of antioxidants sold to manufacturers (CIAA, 1985; Rehwoldt, 1986). However, these data are frequently confidential and therefore not regularly available. From such confidential data, the CIAA (1985) estimated a daily average intake of 1 mg/person in adults in countries of the EEC for all food antioxidants together (i.e. BHA, BHT, gallates, tecopherols and ascorbyl palmitate), increasing to 3 mg/person for individuals with largely aberrant dietary habits. Another method is based on the consumption of fat by man and the maximal BHA and/or BHT content of fats, possibly corrected for the consumption of fat from foods in which BHA and BHT are not allowed. Most reports estimating the daily dietary BHA and/or BHT intake by man are based on this methodology (CIAA, 1985; Kirkpatrick and Lauer, 1986). Daily dietary fat consumption has either been
estimated from the percentage of caloric intake taken as fat (CIAA, 1985) or by a dietary recall survey (Kirkpatrick and Lauer, 1986). The CIAA (1985) estimated a maximal total antioxidant intake of 14mg/person/day for adults in EEC countries. Kirkpatrick and Lauer (1986) estimated that the dietary intake of BHA and other permitted phenolic antioxidants (BHT and propyl gallate) was unlikely to exceed 1 mg/kg/day and on average was less than 0.4mg/kg/day. Although Kirkpatrick and Lauer (1986) indicated that younger children constitute a potential risk group for dietary BHA and/or BHT intake, which is in line with the present study, their report is not applicable to the Dutch situation, since there is a legal difference in the permitted use of BHA and/or BHT in Canada and the USA, and feeding patterns are different in these countries from those in The Netherlands. For instance, the main contribution to BHA and/or BHT intake in the study of Kirkpatrick and Lauer (1986) is made by cereals, a food group that is not consumed so much in The Netherlands as in Canada or the USA. Moreover, BHA and BHT may be found in bread in Canada and the USA as a result of carryover from the fats and oils used to prepare this food, and this is not a possibility in The Netherlands. By contrast with the method of Kirkpatrick and Lauer (1986), in the present report the estimated BHA and/or BHT intake in The Netherlands was based on a 2-day dietary record survey, including all age groups and both sexes. It is emphasized that the present estimates of BHA and/or BHT intake were based on a maximal approach assuming that all of the fat in the food categories included contained maximally permitted levels of antioxidants, according to Dutch legislation, and that these antioxidants were BHA and/or BHT. The estimates accounted neither for losses of BHA and/or BHT during food storage or processing nor for lower levels of BHA and/or BHT in food products as a result of intentional limited use by the manufacturer nor for the addition of other antioxidants (e.g. tocopherols, gallate esters, etc.; Sims and Fioriti, 1980). Reported values may also have been over-estimated as some food categories (e.g. category 6) might have comprised food items that are not allowed to contain BHA and/or BHT (e.g. chocolate). Consequently, actual BHA and/or BHT intakes may be lower than the estimated levels of intake. However, these over-estimates are counter-balanced to some extent by the fact that not all food products that might contain BHA and/or BHT have been included in the selected food categories. It is conceivable that food products in categories 15, 16, 17 and 18 also occasionally contain BHA and/or BHT. In addition, the migration of BHA and BHT from packaging materials, especially those that are waxed, into foods may also contribute to a higher BHA and/or BHT intake by man (Anonymous, 1986a,b; Bieber et al., 1984; Schroeder, 1973; Sims and Fioriti, 1980). Thus, although the applied methodology may have advantages compared with other reported methods, several factors may have given rise to aberrant estimates of the actual daily BHA and/or BHT consumption in The Netherlands. If the estimated maximal antioxidant intake were exclusively BHA, the results indicate that the
Intake of BHA and BHT by man daily dietary consumption of BHA by man in The Netherlands is unlikely to exceed the ADI for this agent, except in extreme cases in l-6-year-olds. Therefore, its application as a food additive should be considered safe. However, it has previously been shown that oral administration of the ADI for BHA (0.5 mg/kg) to man and a 400 times higher dose to the rat (200 mg/kg) resulted in plasma BHA levels within one order of magnitude (Verhagen et al., 1989), which indicates that the current ADI for BHA might not be sufficient to protect man from the possible adverse effects associated with dietary BHA consumption. The ADI for BHA is based on a no-effect level of 62.5 mg/kg body weight for the induction of proliferative changes in the rat forestomach (JECFA, 1986a), which indicates that a toxic effect of BHA in man would probably involve a proliferative effect. If the estimated maximal antioxidant intake were exclusively BHT, it cannot be excluded that the ADIs for BHT might be exceeded in all age and sex groups. Our results raise possible concern about the application of BHT as an additive to human food. Therefore, further research on the actual daily intake of BHT by man is needed. Specifically, the blood coagulation system would probably be the target of BHT toxicity in man, since the lowest ADI for BHT (0-0.05 mg/kg) is based on a no-effect level for (transient) haemorrhagic effects following administration of about 5 mg BHT/kg body weight in a short-term experiment with rats (Anonymous, 1987). In conclusion, based on a maximal approach, it is unlikely that the estimated average daily dietary intake of BHA by man in The Netherlands will exceed the ADI, except in extreme cases in l-6-yearolds. However, it cannot be excluded that the ADI for BHT is exceeded in all age and sex groups. As a result of the high potential consumption of BHT, younger children form a risk group for the toxic effects of BHT. REFERENCES
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