"Suprabasal progesterone, and altered oestradiol-17beta concentrations, seem to play a minor role in cyst formation." (In cows)
"We are particularly concerned about cows' milk, which contains a considerable quantity of estrogens. When we name cows' milk as one of the important routes of human exposure to estrogens, the general response of Western people is that "man has been drinking cows' milk for around 2000 years without apparent harm." However, the milk that we are now consuming is quite different from that consumed 100 years ago."
How does oestradiol-17beta figure in BC. I get lots of links on a google search but am having difficulty in understanding the implications.
What are the levels of progesterone and oestradiol-17beta ingested per pint.
Is this made worse by our search for high yeild cows?
Are they significant in terms of the bodies production?
How are they metabolised?
What impact does fermentation into cheese and yogurt have.?
So many questions - can anybody shed any light?
RB
http://www.ncbi.nlm.nih.gov/entrez/q..._uids=14729019
1: Med Hypotheses. 2004;62(1):133-42. Links
Comment in:
Med Hypotheses. 2005;64(2):429-30.
Estrogen: one of the risk factors in milk for prostate cancer.
• Qin LQ,
• Wang PY,
• Kaneko T,
• Hoshi K,
• Sato A.
Department of Environmental Health, School of Medicine, University of Yamanashi, Shimokato 1110, Tamaho, Yamanashi 409-3898, Japan.
shinr@res.yamanashi-med.ac.jp
Studies to elucidate the cause of prostate cancer have met with little success to date. Epidemiological studies suggested that milk consumption is probably as one of the risk factors for prostate cancer. The studies thus focused on the fat and calcium in milk, but reached no definitive conclusion. According to the measurements of estrogen levels in milk by different studies, it was suggested that estrogen in milk was a possible risk to cause prostate cancer. One reason supporting this hypothesis is that Western diet (characterized by milk/dairy products and meat) causes a trend of increasing levels of estrogens, and Western males show a higher incidence rate of prostate cancer than Asia males. Estrogen levels in prostate fluid are also correlated very well with the prostate cancer. During several decades, estrogens, together with testosterone, was commonly used to induce the rodent model of prostate cancer. Our hypothesis also was supported by the presence of estrogen receptors in the prostate gland and the genotoxic role of estrogens on the prostate gland, as possible mechanisms. Therefore, if modern milk consumption does expose consumers to high levels of estrogen and plays an adverse role in prostate cancer, action should be taken to produce the noncontaminant milk.
PMID: 14729019 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/entrez/q..._uids=16125328
1: Med Hypotheses. 2005;65(6):1028-37. Epub 2005 Aug 24.Click here to read Links
The possible role of female sex hormones in milk from pregnant cows in the development of breast, ovarian and corpus uteri cancers.
* Ganmaa D,
* Sato A.
Department of Environmental Health, Medical University of Yamanashi, Tamaho, Yamanashi 409-3898, Japan.
The continued increase in incidence of some hormone-related cancers worldwide is of great concern. Although estrogen-like substances in the environment were blamed for this increase, the possible role of endogenous estrogens from food has not been widely discussed. We are particularly concerned about cows' milk, which contains a considerable quantity of estrogens. When we name cows' milk as one of the important routes of human exposure to estrogens, the general response of Western people is that "man has been drinking cows' milk for around 2000 years without apparent harm." However, the milk that we are now consuming is quite different from that consumed 100 years ago. Unlike their pasture-fed counterparts of 100 years ago, modern dairy cows are usually pregnant and continue to lactate during the latter half of pregnancy, when the concentration of estrogens in blood, and hence in milk, increases. The correlation of incidence and mortality rates with environmental variables in worldwide countries provides useful clues to the etiology of cancer. In this study, we correlated incidence rates for breast, ovarian, and corpus uteri cancers (1993-97 from Cancer Incidence in Five Continents) with food intake (1961-97 from FAOSTAT) in 40 countries. Meat was most closely correlated with the breast cancer incidence (r=0.827), followed by milk (0.817) and cheese (0.751). Stepwise multiple-regression analysis (SMRA) identified meat as the factor contributing most greatly to the incidence of breast cancer ([R]=0.862). Milk was most closely correlated with the incidence of ovarian cancer (r=0.779), followed by animal fats (0.717) and cheese (0.697). SMRA revealed that milk plus cheese make the greatest contribution to the incidence of ovarian cancer ([R]=0.767). Milk was most closely correlated with corpus uteri cancer (r=0.814), followed by cheese (0.787). SMRA revealed that milk plus cheese make the most significant contribution to the incidence of corpus uteri cancer ([R]=0.861). In conclusion, increased consumption of animal-derived food may have adverse effects on the development of hormone-dependent cancers. Among dietary risk factors, we are most concerned with milk and dairy products, because the milk we drink today is produced from pregnant cows, in which estrogen and progesterone levels are markedly elevated.
PMID: 16125328 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/entrez/q..._uids=12142232
1: Domest Anim Endocrinol. 2002 Jul;23(1-2):125-37.Click here to read Links
Mammary secretion of oestrogens in the cow.
* Janowski T,
* Zdunczyk S,
* Malecki-Tepicht J,
* Baranski W,
* Ras A.
Department of Obstetrics and Pathology of Reproduction, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Poland.
jantom@moskit.uwm.edu.pl
Two experiments in vivo and one experiment in vitro were conduced to examine the mechanisms involved, which lead to mammary secretion of oestrogens and its importance for milk production and udder health in cows. In experiment 1 in six cows of the White-Black breed on day 268 of pregnancy catheters were inserted into uterine vein of pregnant horn, the abdominal aorta and the caudal superficial epigastric (milk) vein. Blood samples for estimation of oestrone, oestrone sulphate, oestradiol-17alpha and -17beta by RIA were obtained daily from day 7 pre-partum until day 1 post-partum. Only the concentration of oestradiol-17beta was statistically higher (P< or =0.01) in mammary venous plasma than in aortal and uterine plasma. In experiment 2 forty late-pregnant cows were divided into two groups according to their milk production in the previous lactation: group 1 (n=20) high-yielding cows (>6500kg milk per lactation), and group 2 (n=20) low-yielding cows (<3700kg milk per lactation). Blood samples for measurement of oestradiol-17beta by RIA were collected from milk and tail veins every fourth day during a period from day 20 prior to parturition to day 4 post-partum. The concentration of oestradiol-17beta was significantly higher (P< or =0.01) in the milk vein than in the peripheral plasma from day 12 pre-partum to parturition. In high-yielding cows the level of oestradiol-17beta in mammary venous blood was significantly higher (P< or =0.01) than in low-yielding cows. In six cows with pathological udder oedema ante-partum the concentration of oestradiol-17beta in milk vein was significantly higher (P< or =0.05) than in control cows. There were no statistically significant differences in the levels of oestradiol-17beta in cows with clinical mastitis (n=10) during 2 weeks after parturition and without it (P> or =0.05). In an in vitro experiment, homogenates of mammary tissue collected on day 7 pre-partum from two cows were incubated with 3H-androstendione. After incubation the samples were extracted and 3H-oestradiol-17beta was separated by HPLC. 3H-oestradiol-17beta was formed in a total yield of 37%. These results indicate that oestrone, oestrone sulphate and oestradiol-17alpha are not secreted by bovine mammary gland. Furthermore, the secretion of oestradiol-17beta starts about day 12 pre-partum and is associated with milk yield and udder oedema. Preliminary in vitro study suggests the synthesis of oestradiol-17beta by mammary tissue.
PMID: 12142232 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/entrez/q..._uids=16149953
1: Reprod Domest Anim. 2005 Oct;40(5):460-7.Click here to read Links
Hormonal and metabolic profiles of high-yielding dairy cows prior to ovarian cyst formation or first ovulation post partum.
* Vanholder T,
* Leroy JL,
* Dewulf J,
* Duchateau L,
* Coryn M,
* de Kruif A,
* Opsomer G.
Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
tom.vanholder@ugent.be
The present study aimed to investigate the pathogenesis of cystic ovarian disease (COD) in high-yielding dairy cows postpartum (pp). Hormonal and metabolic profiles during the first 3 weeks pp as well as during the final week prior to ovulation/cyst formation, were compared between dairy cows that developed either an ovulatory follicle (OV) or a cyst (CYST) < day 60 pp. Thirty-four lactations of 28 high-yielding (9500 kg/305 days) Holstein-Friesian dairy cows were studied. Ovaries of cows were scanned twice a week from day 10 pp on, until ovulation/cyst formation. Milk yield data, body condition scores and blood samples, for determination of oestradiol-17beta, insulin, beta-OH-butyrate and non-esterified fatty acids, were collected simultaneously. Milk samples for progesterone analysis were collected daily. Four lactations were excluded from further analysis because of irregular pp ovarian cyclicity, excluding COD. Eight lactations (26.7%) developed a cyst, while 22 lactations ovulated < days 60 pp. Ovulation and cyst formation occurred at similar times pp. Metabolic and hormonal profiles did not differ between CYST and OV lactations during the first 3 weeks pp. In the final week prior to cyst formation/ovulation, insulin concentrations were lower in CYST than in OV lactations while no differences were observed for any of the other parameters tested. In two lactations, cyst formation was preceded by suprabasal progesterone and increased oestradiol-17beta concentrations. These results suggest that cyst formation in high-yielding dairy cows pp is associated with lower insulin levels but not with other distinct hormonal and metabolic alterations. However from this study, we cannot exclude the involvement of subtle hormonal and metabolic changes in the pathogenesis of ovarian cysts. Suprabasal progesterone, and altered oestradiol-17beta concentrations, seem to play a minor role in cyst formation.
PMID: 16149953 [PubMed - indexed for MEDLINE]
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