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Survey of hormonal levels in meat and poultry sold in Alexandria, Egypt

I.A. Sadek, H.M. Ismail, H.N. Sallam and M. Salem

ABSTRACT An analysis of residues from anabolic agents found in commercially available meat and poultry was undertaken in Alexandria, Egypt. This study shows that beef meat samples purchased from government cooperative supermarkets exhibit higher levels of the synthetic growth promoter, trenbolone acetate, than meat from private butchers; however, estrogen levels were much higher in chicken obtained from private growers. A comparison of different cooking methods was conducted on the chicken samples; boiling without skin is recommended to reduce the consumer's intake of hormonal residues.

Enquête sur les concentrations d'hormones dans la viande et les volailles vendues à Alexandrie (Egypte)

RESUME Une analyse des résidus de certains anabolisants trouvés dans la viande et les volailles commercialisées a été effectuée à Alexandrie (Egypte). Cette enquête a montré que les prélèvements de viande de boeuf achetée dans les coopératives gouvernementales contenaient des concentrations plus élevées d'acétate de trenbolone, substance de synthèse utilisée comme activateur de croissance, que la viande provenant des bouchers privés; toutefois, les concentrations d'oestrogènes étaient beaucoup plus élevées pour les poulets provenant d'éleveurs privés. Une comparaison des différentes méthodes de cuisson a été effectuée avec des échantillons de poulet; la cuisson à l'eau bouillante sans la peau est recommandée pour réduire l'absorption de résidus hormonaux pour le consommateur.

Introduction

There are now several hormones and hormone-like agents with marked ability to improve the rate of growth and efficiency of feed intake for farm animals. The Joint (FAO/WHO) Codex Alimentarius Commission, in particular its Codex Committee for Veterinary Drug Residues in Food, has approved the use of a number of natural and synthetic growth promoters for use in food-producing animals, including the endogenous growth promoters estradiol-17 beta, progesterone and testosterone, and the synthetic growth promoters, trenbolone acetate and zeranol. In most countries the use of anabolic agents for these purposes is regulated to protect human and animal health. In addition, some countries like the United States of America feel that controlled use of certain compounds is safe; other countries strictly prohibit their application and, in particular, the use of "estrogens" [1,2]. The illegal use of these anabolic agents entails a special risk to the animals [3], and probably to the consumer.

The purposes of the present study were, first, to analyse the levels of anabolic agents in meat and poultry sold in Alexandria, Egypt; and, second, to determine the effect different types of home cooking might have on the level of hormonal residue in chicken previously fed with contraceptive pills as anabolic agent.

Materials and methods

Beef and liver samples

Beef and liver samples were purchased from government cooperative supermarkets and private butchers located in the El-Amria, El-Gomrok, West, Middle, East and Montaza districts of Alexandria, Egypt.

Chicken samples

Samples of non-free-range chicken found in government cooperative supermarkets and private shops, which slaughter their own battery chickens, were analysed during this survey. Chicken samples were collected from the same districts as above.

Processing experiment

Chicken samples of the breed Matrouh Pallet, 2 weeks of age, were used. The birds were fed broiler diet ad libitum and contraceptive pills in the same dose used by poultry growers in Egypt (four strips of Anovlar/100 kg diet) for 4 weeks as described in an earlier article [3]. Each strip contains 21 pills and each pill contains 21 mg norethisterone acetate + 1.05 mg of ethinyl estradiol. Three birds were subjected to each type of home cooking as follows:

• Boiling in water with skin
• Boiling in water without skin
• Oven roasting with skin
• Oven roasting without skin
• Grilling with skin
• Grilling without skin.

Sample preparation

Beef and chicken muscles were filleted and frozen prior to analysis. Also, livers of both beef and chicken samples were homogenized in a kitchen blender, then 80-100 g of the homogenate was sealed in a plastic bag prior to analysis.

Methods of analysis

Analysis was carried out by using high performance liquid chromatography (HPLC) as described before [1,4], column 250 × 4 mm stationary phase CH-18 Super Merck. The wavelength was 225 nm for 17-estradiol and diethylstilbestrol; the
wavelength was 240 nm for zeranol and 340 nm for trenbolone.

Results and discussion

The results show that beef samples from government cooperative supermarkets exhibit higher levels of trenbolone in comparison to meat from private butchers (Table 1). It is well known that free and conjugated 17b-trenbolone have been determined in muscle, liver, kidney, fat and plasma [5,9].

Attempts have been made to determine zeranol residue in tissues of cattle [5,9]. The beef meat and liver collected from government cooperative supermarkets and private butchers were free from zeranol. The levels of diethylstilbestrol (DES) and estradiol were also very low; it should be noted that at present the use of DES in food animals for fattening purposes is prohibited worldwide due to its mutagenic and carcinogenic activity [5]. Synthetic estrogens have also been shown to stimulate liver cell proliferation [6].

The present data clearly demonstrate that the level of estradiol is much higher in chicken from private growers in comparison to those obtained from government cooperative supermarkets (Table 2). It appears that some poultry growers in Egypt use hormones or hormone-like agents to improve the rate of growth. It is worth mentioning that feeding chickens with oral contraceptive steroids leads to the formation of high estrogen residues in muscle and liver in comparison to controls. It has been suggested that oral contraceptive steroids can act as promoters of growth [7]; however, the results of several studies have described the appearance of hepatocellular carcinoma in women using oral contraceptive steroids for prolonged periods of time [8].

The use of hormones was legally permitted for some time in various countries. The question which now arises is whether
the type of home cooking might affect the level of hormonal residue in chicken.   Table 3 shows that the best method for cooking is boiling without skin and hence removal of the skin, which contains fat, could contribute considerably to the decrease of the level of estrogen intake by consumers.  In general the residue of estrogens found in fat exceed those found in the other tissues [9]. Data on residue levels obtained from these results clearly indicate that anabolic agents in beef and chicken entail a special risk to public health.

Acknowledgements

The authors gratefully acknowledge the support given by the World Health Organization for this work.

References

1. Hoffmann B. Use of radioimmunoassay procedures for the determination of sex hormones in animal tissues. Journal of steroid biochemistry, 1983, 19:947-51.

2. Hoffmann B, Evers P. Anabolic agents with sex hormone-like activities: problems of residues. In: Rico G, ed. Drug residues in animals. Veterinary science and comparative medicine. New York, Academic Press, 1986:111-46.

3. Sadek IA, Ismail HM, Sallam HN, Salem M. Some aspects of the use of oral con
traceptives as growth-promoting agents in poultry. Eastern Mediterranean health journal, 1995, 1:241-7.

4. O'Keeffe M. Trenbolone levels in tissues of trenbolone acetate-implanted steers: radioimmunoassay determination using different antisera. British veterinary journal, T., 1984, 140:592-9.

5. Shepherd M. Analysis of veterinary drug residues in edible animal products. In: Creaser C, Purchase R, eds. Food contaminants sources and surveillance. Melksham UK, Redwood Press Ltd., 1991:109-76.

6. Cole FM, Sweeney GD. Changes in rat hepatocyte plasma membranes caused by synthetic estrogens. Laboratory investigation, 1980, 42:225-30.

7. Sadek IA, Abdelmeguid N. Enhancement of liver tumour in the Egyptian toad by oral contraceptive steroids. Journal of nutrition, growth and cancer, 1986, 3:239-44.

8. Henderson BE et al. Hepatocellular carcinoma and oral contraceptives. British journal of cancer, 1983, 48:437-44.

9. FAO/WHO. Residues of some veterinary drugs in animals and foods. Rome, Food and Agriculture Organization of the United Nations, 1987 (FAO Food and Nutrition Paper No. 41.)