Mauro Lombardo
www.maurolombardo.it
L 'excessive exposure to hormones has potential adverse consequences for human health, particularly with regard to changes involving the endocrine glands during puberty, the system immune to the effects of genotoxic and carcinogenic. Six growth hormones used in meat production (17-beta estradiol, progesterone, testosterone, zeranol and trenbolone acetate and melengesterolo) may, as appropriate, have deleterious effects on human health. In particular, the group most at risk is made by children and boys until puberty. The evidence is sufficient to prove it, even if they cover different levels and the available data do not permit a quantitative assessment of risks, which are no less real even if the use of small doses. In fact, none of these hormones can make a critical threshold. The 17-beta estradiol on the contrary has been identified as a complete carcinogen, and has the effect will be to initiate and promote the development of cancer (IARC, 1987).
The use of antibiotics and growth promoters in animal husbandry and disseminated in order to decrease fat storage and increase muscle mass.
The discovery of the risks related to the use of these substances has led the EU to adopt some guidelines to regulate in a uniform matter. Recently about the implementation of Directive in Italy EC 96/22 and 96/23 EC concerning the prohibition on the use of hormonal substances, thyrostatic and beta antagonists in animal production. In contrast to the U.S., Canada and certain other third countries, approved the hormones can be bought without prescriptions, and be used without the supervision of veterinarians.
A series of experimental data and epidemiological studies have demonstrated the toxicity of estrogen synthesis both in animals and humans. The diethylstilbestrol (DES), which is among the most widely used synthetic estrogen because of its low cost, if administered for long periods at low doses (0.1 to 2 ng / kg body weight) in experimental animals causes histological changes in liver, kidney, and sperm in the seminiferous tubules, causing serious disturbances of reproductive functions. The metabolites of estrogen also have the ability to damage DNA and cause mutations (Service, 1998). This property could be the start event for many human cancers, including tumors of the breast, uterus, ovaries, prostate and possibly the brain (Cavalieri et al., 1998). Excessive consumption of estrogen in humans results in a negative feedback effect of the hormones with arrest of spermatogenesis and azoospermia in males, interrupted ovarian cycle, block ovulation, menstrual irregularities and infertility in women (Perez-Comas, 1988). The administration of low doses of estradiol (4μg/giorno) for children weighing 30-40 kg causes an acceleration of more than 60% of bone growth compared to the physiological parameters and in both males and females, abnormal sexual development and puberty: Telarc, pubarca, ovarian stimulation syndrome, POS (Perez-Comaz, 1988; Fara etal. 1979; Pasquino et al).
In Italy the legislature prohibits absolutely the use of hormonal substances in animals for breeding purposes auxin. However, in the late 70's, have been repeatedly observed by pediatricians children presenting with symptoms characteristic of the subjects accidentally exposed to estrogenic substances. Because these observations have sometimes taken an epidemic, the suspicion arose that the cause was the ingestion of these events in a more or less continuous meat, especially beef, containing estrogen. Given that the veal is very popular in the first year of life, feeding the baby, as baby food, the presence of estrogenic substances in food meat, especially beef, and the consequent possibility of ingestion of reiterative these substances from the beginning of the developmental age have raised a very sensitive issue. In 1978, the National Institute of Health (ISS) conducted a detailed study on the effects of pharmaco-toxicology of sex hormones like auxin illegally used in animal husbandry and the possible risk of the exposed population. Of the 82 samples came all'lSS by the year 1980, well 78 were found positive for the presence of substances with estrogenic activity, as determined qualitatively DES. The amount found was substantial (30 to 150 pg per kg homogenate) and corresponded to the dose potentially carcinogenic to the rat. This could explain the finding of such large quantities only by assuming that the product homogenized muscle were present in those parts of the animal that had been site of DES. It is well known that the synthetic estrogen, once injected into the calf, is not entirely absorbed into the bloodstream, but at least 10-20% (about 10-30mg of DES) may remain for many months in the tissue within the injection.
However, further study is needed to quantify the level of antibiotics and growth promoters in meat consumed in our tables and more quantitative risk assessments relating intake of these substances.
