Also see:
Nutrition and Brain Growth in Chick Embryos
PUFA, Estrogen, Obesity and Early Onset of Puberty
Quotes by Ray Peat, PhD:
“It seems clear that the course of degenerative aging processes is set in young adulthood (or even earlier), and that it is never too early to be concerned with correcting processes that are going in the wrong direction. (See Walker, et al., 1988, and Smith, et al., 1992.)
In “The Biological Generality of Progesterone” (1979) I proposed that the life-long trajectory of energy production and longevity was strongly influenced by prenatal nutrition and progesterone. This idea was based on work by people such as Marion Diamond, who showed that prenatal progesterone enlarges the cortex of the brain, and that estrogen makes it smaller, and Leonell Strong, who showed that a treatment that lowered the estrogen function in a young mouse could produce cancer-free offspring for several generations. Strong’s work was very encouraging, because it showed that biological problems that had been “bred in” over many generations could be corrected by some simple metabolic treatments.”
“Many factors, including poor nutrition, climate, emotional or physical stress (even excessive running) and toxins, can cause a progesterone deficiency. Use of estrogens, birth control pills and even IUDs can also bring about a deficiency. Animal studies and clinical experience suggests that the prenatal hormonal environment (a mother’s excess of estrogen during pregnancy) can incline a person toward a deficiency of progesterone relative to estrogen.”
PLoS Med. 2007 May;4(5):e167.
Childhood conditions influence adult progesterone levels.
Núñez-de la Mora A, Chatterton RT, Choudhury OA, Napolitano DA, Bentley GR.
BACKGROUND:
Average profiles of salivary progesterone in women vary significantly at the inter- and intrapopulation level as a function of age and acute energetic conditions related to energy intake, energy expenditure, or a combination of both. In addition to acute stressors, baseline progesterone levels differ among populations. The causes of such chronic differences are not well understood, but it has been hypothesised that they may result from varying tempos of growth and maturation and, by implication, from diverse environmental conditions encountered during childhood and adolescence.
METHODS AND FINDINGS:
To test this hypothesis, we conducted a migrant study among first- and second-generation Bangladeshi women aged 19-39 who migrated to London, UK at different points in the life-course, women still resident in Bangladesh, and women of European descent living in neighbourhoods similar to those of the migrants in London (total n = 227). Data collected included saliva samples for radioimmunoassay of progesterone, anthropometrics, and information from questionnaires on diet, lifestyle, and health. Results from multiple linear regression, controlled for anthropometric and reproductive variables, show that women who spend their childhood in conditions of low energy expenditure, stable energy intake, good sanitation, low immune challenges, and good health care in the UK have up to 103% higher levels of salivary progesterone and an earlier maturation than women who develop in less optimal conditions in Sylhet, Bangladesh (F9,178 = 5.05, p < 0.001, standard error of the mean = 0.32; adjusted R(2) = 0.16). Our results point to the period prior to puberty as a sensitive phase when changes in environmental conditions positively impact developmental tempos such as menarcheal age (F2,81 = 3.21, p = 0.03) and patterns of ovarian function as measured using salivary progesterone (F2,81 = 3.14, p = 0.04).
CONCLUSIONS:
This research demonstrates that human females use an extended period of the life cycle prior to reproductive maturation to monitor their environment and to modulate reproductive steroid levels in accordance with projected conditions they might encounter as adults. Given the prolonged investment of human pregnancy and lactation, such plasticity (extending beyond any intrauterine programming) enables a more flexible and finely tuned adjustment to the potential constraints or opportunities of the later adult environment. This research is the first, to our knowledge, to demonstrate a postuterine developmental component to variation in reproductive steroid levels in women.
