This 2018 Korean review discussed aspects of the hypothalamus and aging:
“A majority of physiological functions that decline with aging are broadly governed by the hypothalamus, a brain region controlling development, metabolism, reproduction, circadian rhythm, and homeostasis. In addition, the hypothalamus is poised to connect the brain and the body so that the environmental information affecting aging can be transmitted through the hypothalamus to affect the systematic aging of the peripheral organs.
The hypothalamus is hypothesized to be a primary regulator of the process of aging of the entire body. This review aims to assess the contribution of hypothalamic aging to the age-related decline in body functions, particularly from the perspective of:
- energy homeostasis,
- hormonal balance,
- circadian rhythm, and
and to highlight its underlying cellular mechanisms with a focus on:
- nutrient sensing
- loss of stem cell,
- loss of proteostasis, and
- epigenetic alterations.”
The reviewers didn’t consider aging to be an “unintended consequence” of development. This perspective was found in a reference to A study of DNA methylation and age:
“Aging is not and cannot be programmed. Instead, aging is a continuation of developmental growth, driven by genetic pathways.
Genetic programs determine developmental growth and the onset of reproduction. When these programs are completed, they are not switched off.
Aging has no purpose (neither for individuals nor for group), no intention. Nature does not select for quasi-programs. It selects for robust developmental growth.”
The epigenetic clock theory of aging cited the same author, and modified his point to say:
This review’s opposite paradigm was:
“The hypothalamus is hypothesized to be a primary regulator of the process of aging.”
Almost all of the details discussed were from rodent studies.
I favor the “unintended consequence” explanation of aging. As detailed in How to cure the ultimate causes of migraines? and its references, the hypothalamus is a brain structure that lacks feedback mechanisms for several of its activities.
This structure develops shortly after conception and has an active prenatal role. The hypothalamus plays its part in getting us developed and ready to reproduce, with several feedback loops being evolutionarily unnecessary.
The hypothalamus perfectly illustrates the point of:
“When these programs are completed, they are not switched off.”
Should hypothalamic activity not winding down when its developmental role is over be interpreted to construe a role that has some other meaning or purpose as we age?
https://www.sciencedirect.com/science/article/pii/S0047637418300502 “Role of hypothalamus in aging and its underlying cellular mechanisms” (not freely available)