Effect of cooking on concentrations of β-estradiol and metabolites in model matrices and beef

Validation of a GC- and LC-MS/MS based method for the quantification of 22 estrogens and its application to human plasma

In epidemiological studies, blood levels of 17β-estradiol (E2) are associated with hormone-dependent diseases. The lack of specific methods impedes studies on the role of E2 metabolites and their conjugates in the etiology of hormone-dependent diseases. Stable-isotope dilution tandem mass spectrometry methods (coupled to gas chromatography and liquid chromatography systems) for the analysis of 22 endogenous estrogens, including both oxidative metabolites, as well as sulfates and glucuronides, was validated and the method applied to plasma of women with no breast cancer. No changes in estrogen profile during sample cleanup were observed and values for limit of detection (7fmol/ml - 2 pmol/ml), accuracies (80-122%) as well as intra- and inter-day precision (below 28%) at levels near the limit of quantification were acceptable. In human plasma only seven estrogens were detected and estrone conjugates contributed most to the estrogen profile.

Advances in Nutritional Epigenetics-A Fresh Perspective for an Old Idea. Lessons Learned, Limitations, and Future Directions

Nutritional epigenetics is a rapidly expanding field of research, and the natural modulation of the genome is a non-invasive, sustainable, and personalized alternative to gene-editing for chronic disease management. Genetic differences and epigenetic inflexibility resulting in abnormal gene expression, differential or aberrant methylation patterns account for the vast majority of diseases. The expanding understanding of biological evolution and the environmental influence on epigenetics and natural selection requires relearning of once thought to be well-understood concepts. This research explores the potential for natural modulation by the less understood epigenetic modifications such as ubiquitination, nitrosylation, glycosylation, phosphorylation, and serotonylation concluding that the under-appreciated acetylation and mitochondrial dependant downstream epigenetic post-translational modifications may be the pinnacle of the epigenomic hierarchy, essential for optimal health, including sustainable cellular energy production. With an emphasis on lessons learned, this conceptional exploration provides a fresh perspective on methylation, demonstrating how increases in environmental methane drive an evolutionary down regulation of endogenous methyl groups synthesis and demonstrates how epigenetic mechanisms are cell-specific, making supplementation with methyl cofactors throughout differentiation unpredictable. Interference with the epigenomic hierarchy may result in epigenetic inflexibility, symptom relief and disease concomitantly and may be responsible for the increased incidence of neurological disease such as autism spectrum disorder.

Investigation of zeranol in beef of Ukrainian production and its reduction with various technological processing

Synthetic growth stimulants are widely used to get high productivity of animals. These preparations can accumulate in the meat and their residual quantities will adversely affect the health of consumers. The purpose of the work was to monitor the content of zeranol, growth stimulant of ruminants in beef which goes to meat processing enterprises of the Western region of Ukraine and to determine the effect of heat treatment on its quantity. It was found out that 29.8% of beef samples taken at meat processing enterprises contained a stimulant for the growth of ruminant zeranol. It was found that during the storage of beef samples frozen at a temperature of -18 °C with different content of zeranol there is a decrease in its number. The most intense process of destruction of zeranol occurred during the first month of storage, during this period of time the amount of zeranol is reduced by an average of 20%, regardless of the initial content. Within two months of storage of frozen beef, the content of zeranol decreases by 28.2 ±0.17%, and at the end of the sixth month its quantity decreases to 33.2 ±0.58%. It was also found that the dynamics of zeranol reducing in beef samples with large quantities (22.5 μg.kg-1) and small (2.3 μg.kg-1) were the same. It was set up that during 30 min of meat cooking there was a decrease in the content of zeranol 24.7 ±0.23% and 32.0 ±0.35% for 60 min, compared to its content in fresh meat. At the same time, when stored in the frozen state and subsequent cooking, the reduction of zeranol content in meat was 39.3 ±0.3%. Therefore, it is proposed to revise and amendments into the regulatory documents of Ukraine regarding the control and supervision of the presence of hormone (zeranol) residues in meat and meat products in order to prevent their sale and consumption by humans.

An In Vitro Comparison of Estrogenic Equivalents Per Serving Size of Some Common Foods

The public assumes that some foods, such as milk and ground beef from cattle receiving steroidal implants, are associated with estrogenic hormones, while other foods are presumed "safe" or nonestrogenic. Here, we investigate these assumptions by assessing the relative estrogenic activity of a serving size of four foods: skim milk (8 oz), rice (48 g dry wt) in cooking bag, ground beef patties from steers raised with or without hormone implantation (quarter lb each, 114 g), and tofu burgers (isocaloric to beef burger, 198 g), using an in vitro assay (E-Screen). Mean picogram (pg) estradiol equivalents (E2Eqs) on a serving basis were as follows: skim milk 120; rice 400; rice prepared in cooking bag 370; rice boiling bag alone 4 pg per bag, ground beef burger (obtained from the tissue of cattle that had received no hormone implants) 389, beef burger (obtained from cattle that had received hormone implant) 384, and tofu burger 1,020,000. Rice E2Eqs were highly variable, but the plastic cooking bags provided by the manufacturer added negligible E2Eqs. The source of estrogenic activity in rice may have been due to contamination with the mycotoxin zearalenone. The E-Screen E2Eqs of tofu burger extracts agreed with those predicted based on chemical concentrations of the most estrogenic component times their E2Eq factor. While a tofu burger contained around three times the estrogenic activity of a daily dose of estrogen replacement therapy (125 mg, Premarin®, 303,000 pg); the other foods--a quarter pound ground beef burger at approximately equal calorie count, a serving of milk, or rice, were all at least 750-fold less estrogenic. PRACTICAL APPLICATION: When consuming the recognized serving size of a food, how much estrogenic activity can we expect? While the public assumes that some foods, such as milk and ground beef from cattle receiving steroidal implants, are associated with estrogenic hormones, other foods are presumed "safe" or nonestrogenic. Using one assay, a tofu burger contained three times the estrogenic activity of a dose of hormone replacement therapy commonly prescribed for women after hysterectomy or menopause (Premarin®); while other foods--a quarter pound ground beef burger at approximately equal calorie count, a serving of milk, or rice, were all at least 750-fold less estrogenic.

Hormones in Food as a Potential Risk for Human Reproductive and Health Disorders

In the last 60 years, milk, meat, and egg worldwide consumption per capita increased 2-, 3-, and 5-fold, respectively. In the same period, several studies have reported a drop of semen quality and an increased incidence of cryptorchidism, hypospadias, and some hormone-related cancers (testicular, prostate, breast, endometrial cancer) in humans. A possible reason for these disruptions is increased exposure to exogenous hormones in food of animal origin. Hormones in food are considered to affect the endocrine system and cell signaling and thus disrupt homeostasis in the consumers. Since food safety assurance is a part of the veterinary service, the risk assessment of hormones in food as potential disruptive compounds is a significant challenge. Numerous cohort and epidemiologic studies and meta-analyses have been performed with respect to find an association between the consumption of food of animal origin and particular health disorders. Additionally, several studies in animal models have been performed to explain the mechanisms of disruptive effects of exogenous hormones. Since contradictory results have been reported, there is no general conclusion about the disruptive effects of exogenous hormones. Further experiments on animals in which long-term treatment with exogenous hormones is performed and further comprehensive endocrinological, toxicological, and human epidemiological studies are needed to confirm or deny the role of exogenous hormones in human health disorders. Moreover, long-term exposure to a combination of several exogenous compounds, such as environmental pollutants and dietary hormones and their additive effects, are also not well known and should be a topic for further studies.

Consumption of ground beef obtained from cattle that had received steroidal growth promotants does not trigger early onset of estrus in prepubertal pigs

BACKGROUND

The earlier onset of puberty seen in young American girls has led researchers to question if a causal relation exists between dietary sources of estrogenic compounds and precocious puberty.

OBJECTIVE

Using the prepubertal gilt (young female pig) as an animal model, our hypothesis is that feeding beef obtained from cattle receiving growth-promoting steroidal implants postweaning does not alter the onset of puberty or the peripubertal body composition of gilts compared with contemporaries fed nonimplanted "natural" beef or a common meat alternative, tofu.

METHOD

The base diet was formulated using canola meal replacing soybean meal to reduce diet estrogenicity. Feed intake was monitored and controlled to ensure similar intake. Gilts were assigned to treatments based on dam and initial body weight (mean: 24.5 ± 3.20 kg) at 61 d of age. The negative control base diet was supplemented with daily feedings of a cooked patty from nonimplanted steers (natural), from steers that had been treated with growth promotants [100 mg trenbolone acetate and 14 mg estradiol (E2) benzoate; implanted], or cooked tofu patty.

RESULTS

E2 equivalents (nanogram per kilogram, as fed as analyzed by E-Screen) of the tofu (a soy-based product) supplement were ∼570 times the natural and ∼170 times the implanted supplements. There were no observed differences across treatments in live weight gain (P = 0.90), longissimus muscle area developed at the 10th and 11th rib interface (P = 0.46), and subcutaneous fat deposition (P = 0.41) at the same location over time or in the number of days to reach estrus (P = 0.55).

CONCLUSIONS

Consumption of beef from growth implanted or natural steers or tofu at levels similar to those typically consumed by humans did not impact growth or onset of estrus in these prepubertal gilts.