Progesterone concentrations in samples of saliva from adolescent girls living in Britain and Thailand, two countries where women are at widely differing risk of breast cancer

Danutra, V.; Turkes, A.; Read, G F; Wilson, Douglas W.; Griffiths, V.; Jones, R. J.; Griffiths, K.

doi:10.1677/joe.0.1210375

Cited by 20 publications

(6 citation statements)

References 24 publications

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“…However, follicular progesterone was lower in those with menarche either 11 or 14 years of age, and menarcheal age was not related to any luteal-progesterone index. Particularly revealing, even when matched for chronological and gynecological age (time since menarche), British girls had higher levels of progesterone than Thai girls (Danutra et al, 1989). Clearly, whatever factors shape menarcheal age and/or ovarian steroid levels, these two aspects of ovarian functioning can vary independently to some degree.…”

Section: Dietary Composition Despite Vast Differences In Diets Mostmentioning

confidence: 98%

The ecology and evolutionary endocrinology of reproduction in the human female

Vitzthum

2009

American J Phys Anthropol

152

114

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Human reproductive ecology (HRE) is the study of the mechanisms that link variation in reproductive traits with variation in local habitats. Empirical and theoretical contributions from biological anthropology, physiology, and demography have established the foundation necessary for developing a comprehensive understanding, grounded in life history theory (LHT), of temporal, individual, and populational variation in women's reproductive functioning. LHT posits that natural selection leads to the evolution of mechanisms that tend to allocate resources to the competing demands of growth, reproduction, and survival such that fitness is locally maximized. (That is, among alternative allocation patterns exhibited in a population, those having the highest inclusive fitness will become more common over generational time.) Hence, strategic modulation of reproductive effort is potentially adaptive because investment in a new conception may risk one's own survival, future reproductive opportunities, and/or current offspring survival. The hypothalamic-pituitary-ovarian (HPO) axis is the principal neuroendocrine pathway by which the human female modulates reproductive functioning according to the changing conditions in her habitat. Adjustments of reproductive investment in a potential conception are manifested in temporal and individual variation in ovarian cycle length, ovulation, hormone levels, and the probability of conception. Understanding the extent and causes of adaptive and non-adaptive variation in ovarian functioning is fundamental to ascertaining the proximate and remote determinants of human reproductive patterns. In this review I consider what is known and what still needs to be learned of the ecology of women's reproductive biology, beginning with a discussion of the principal explanatory frameworks in HRE and the biometry of ovarian functioning. Turning next to empirical studies, it is evident that marked variation between cycles, women, and populations is the norm rather than an aberration. Other than woman's age, the determinants of these differences are not well characterized, although developmental conditions, dietary practices, genetic variation, and epigenetic mechanisms have all been hypothesized to play some role. It is also evident that the reproductive functioning of women born and living in arduous conditions is not analogous to that of athletes, dieters, or even the lower end of the ''normal range'' of HPO functioning in wealthier populations. Contrary to the presumption that humans have low fecundity and an inefficient reproductive system, both theory and present evidence suggest that we may actually have very high fecundity and a reproductive system that has evolved to be flexible, ruthlessly efficient and, most importantly, strategic. It would be instructive to know not only by what physiological mechanisms a just apportionment is made between the nutriment devoted to the gonads and that devoted to the rest of the parental organism, but also what circumstances in the life-history and e...

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Section: Dietary Composition Despite Vast Differences In Diets Mostmentioning

confidence: 98%

The ecology and evolutionary endocrinology of reproduction in the human female

Vitzthum

2009

American J Phys Anthropol

152

114

View full text Add to dashboard Cite

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“…The phyto‐estrogens genistein and daidzein may well beneficially inﬂuence male puberty. A Western diet lowers the age of menarche – there are marked differences in the onset of hormone secretion and ovulatory cycles between girls in Britain and Thailand 56,57 – and may inﬂuence the LH‐RH pulse generator in males.…”

Section: Adolescence Puberty and Sexualitymentioning

confidence: 99%

Estrogens and aspects of prostate disease

Prezioso¹,

Denis²,

Klocker³

et al. 2006

Int J of Urology

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Estrogens have long been associated with the processes involved in prostate carcinogenesis, particularly in cancer suppression. However, the synergistic influence of low concentrations of estrogens, together with androgens, in promoting aberrant growth of the gland has also been recognized. As new insights into the complex molecular events implicated in growth regulation of the prostate are revealed, the role of the estrogens has become clearer. The present review considers this role in relation to the pathogenesis of prostate cancer and the potential cancer-repressive influence of the dietary estrogens.

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“…However, plasma Pg levels among the groups were similar, which corresponds with the findings of Rose et al (22 ), who measured Pg in plasma collected during the luteal phase in women on bran diets. Danutra et al (32) found differences in extent of Pg activity in saliva from adolescent girls living in Britain and Thailand. The age at which Pg secretion was established was earlier for the British girls than for the Thai girls.…”

Section: Discussionmentioning

confidence: 99%

Effects of wheat bran on blood and tissue hormone levels in adult female rats

Arts

Thijssen

1992

Acta Endocrinologica

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Arts CJM, Thijssen JHH. Effects of wheat bran on blood and tissue hormone levels in adult female rats.The protective effect of dietary fiber on breast cancer development might be explained by the interaction between dietary fiber and hormonal processes. We studied the effects of dietary fiber and the effects of a reduced energy intake on the exposure of mammary tissue to both estrogens and progesterone, as well as the blood plasma levels of these steroids and of LH and FSH. Adult female Fisher rats were fed ad libitum either a low-fiber diet (0.5% dietary fiber based on wheat flour) or a high-fiber diet (9.2% dietary fiber based on wheat bran). A third group was used to control for the reduced energy intake of the hi gh\ x=req-\ fiber group and was fed the low-fiber diet restricted. Energy intake was similar for the second and third groups. Four out of 14 rats of the high-fiber group and 4 out of 15 rats of the restricted low-fiber groups were not in cycle after seven weeks on the experimental diets, indicating that the estrous cycle was significantly affected by a reduced energy intake. Exposure of mammary tissue to estrogens did not differ among the groups, as measured by estrone, estradiol-17\g=b\,estriol and peroxidase activity. During the peak period, plasma LH levels were significantly higher in the high-fiber group than in the two low-fiber groups. FSH and progesterone plasma levels were unaffected by the experimental diets. It is concluded that dietary fiber affects the hormonal processes involved in breast cancer development. The increased LH levels indicate an increased estrogen production in the ad libitum high-fiber group. Cor JM Arts, TNO/Toxicology and Nutrition Institute, In various studies an inverse relation has been observed between dietary fiber intake and breast or mammary cancer. Lower plasma estrogen levels have been meas¬ ured in vegetarian postmenopausal women (1), and a reduced risk of breast cancer has been observed in women with a relatively high intake of dietary fiber (2). In two lifespan studies (3, 4), mammary cancer inci¬ dence was significantly lower in rats fed a high-fiber (HF) diet than in those on a low-fiber (LF) diet. Moreover, NMU-induced mammary tumors in rats fed a HF diet weighed significantly less than those in rats fed a LF diet (5,6). Estrogens have been reported to play a crucial role in mammary carcinogenesis. An increased exposure of the estrogen-sensitive tissue to estrogens would result in a higher risk of mammary cancer at the initiation or promotion phase (7). In a previous study (5), a clear interruption of the enterohepatic circulation of estrogens was observed, resulting in a three to fourfold higher fecal estrogen excretion in rats fed the HF diet than in those fed the LF diet, contrary to urinary estrone (Ei ) excretion, which was lower (p<0.05) in the HF group. Despite the increased fecal estrogen excretion, plasma estradiol-17ß (E2) levels were similar in both groups. This latter finding may be explained by a negative feedback mechanism, i.e. an increase...

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Progesterone concentrations in samples of saliva from adolescent girls living in Britain and Thailand, two countries where women are at widely differing risk of breast cancer

Cited by 20 publications

References 24 publications

The ecology and evolutionary endocrinology of reproduction in the human female

The ecology and evolutionary endocrinology of reproduction in the human female

Estrogens and aspects of prostate disease

Effects of wheat bran on blood and tissue hormone levels in adult female rats

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