We may think of DHEA primarily as a supporting hormone for ovarian health for women. However, DHEA may play other important roles in the body – one of which is to support normal brain development during pregnancy. Interestingly, some biologists and anthropologists think that DHEA may be what made us human in this regard. It’s more speculative than our usual DHEA explainers, but it’s a fun one with potential significance on prenatal health. Let’s break it down.
DHEA may support fetal brain development
We know that the fetus produces a large amount of DHEA in the adrenal glands – enough to increase the amount of DHEA in the mom’s body during pregnancy, in fact. This extra DHEA is primarily taken up by the placenta and converted into an estrogen, which helps the uterus and placenta grow with the baby to maintain a healthy pregnancy.
Doctors think, however, that a part of this additional DHEA is also used to support fetal brain development during pregnancy. The mechanism is not very well understood, but scientists are working for a better understanding. A review of animal studies, for example, suggested that DHEA may regulate the effects of another steroid hormone, glucocorticoids, necessary for normal brain development.
DHEA may also play an important role in brain development long after birth. DHEA, as a neuroactive neurosteroid, may modulate the baby’s early brain development. The increase in DHEA levels as our adrenal glands start producing it at around ages 5-11 has also been suggested as a mechanism to support cognitive and behavioral maturation before and during puberty.
What does this have to do with human evolution?
So, what does DHEA’s role in the baby’s brain development have to do with human evolution? Biologist James Michael Howard posits that an increase in DHEA (and testosterone) levels in humans – especially in females – may have played a significant role in the survival and success of our species in a challenging climate.
In an article published in the journal Rivista di Biologia/Biology Forum and reposted here, Howard explains:
- Thermogenesis: DHEA increases how much heat our body can produce from the food we eat. At the end of the Cretaceous period, when an impact winter from an asteroid wiped out three-quarter of the species on the planet, early humans may have been able to survive partly because of the thermogenic benefit of increased DHEA levels, as they were able to stay warm from the limited amount of food available.
- Larger brains and stronger bones: The same increase in DHEA (and testosterone) levels, especially in females, may have led our species to have advantage over other hominid species. Higher DHEA levels gave rise to some of homo sapiens’ defining characteristics: Larger brains, stronger and larger bones and females closer to males in body size.
- Further frontal brain growth: As the climate warmed back up, more of the DHEA may have been diverted from generating heat to driving brain growth, especially in the frontal region – which further differentiated homo sapiens (that’s us) from other hominids and primates.
The takeaway
While certainly speculative, Howard’s argument is intriguing, given what we know about DHEA’s role in the development of the physical brain, as well as its functions. It’s also a reminder that – despite the “male hormone” moniker – androgens like DHEA and testosterone play important roles in women’s health.
Too much androgen in women is of course a problem, but we shouldn’t automatically consider androgens as detrimental to women’s reproductive or prenatal health. They are necessary for many biological processes that support our lives, including reproduction.
For a more detailed history of how we came to be as a species and what role testosterone and DHEA may have played in that evolution, read Howard’s full post.
