Early-life stress and reproductive cost: A two-hit developmental model of accelerated aging?

Abstract

a b s t r a c tTwo seemingly independent bodies of research suggest a two-hit model of accelerated aging, one highlighting early-life stress and the other reproduction. The first, informed by developmental models of earlylife stress, highlights reduced longevity effects of early adversity on telomere erosion, whereas the second, informed by evolutionary theories of aging, highlights such effects with regard to reproductive cost (in females). The fact that both early-life adversity and reproductive effort are associated with shorter telomeres and increased oxidative stress raises the prospect, consistent with life-history theory, that these two theoretical frameworks currently informing much research are tapping into the same evolutionarydevelopmental process of increased senescence and reduced longevity. Here we propose a mechanistic view of a two-hit model of accelerated aging in human females through (a) early-life adversity and (b) early reproduction, via a process of telomere erosion, while highlighting mediating biological embedding mechanisms that might link these two developmental aging processes.

Early-Life Experiences and Telomere Length in Adult Rhesus Monkeys: An Exploratory Study

“…Several different lines of research have found links between adverse life experiences in the early years of life and adult telomere length (11–13). These studies are difficult to interpret given that adversities tend to co-occur.…”

“…For example, perceived neighborhood quality (4–6), anxiety (7), exposure to intimate partner violence (8, 9), and being the primary caregiver of a child with a chronic condition (10) are all inversely correlated with telomere length, as typically measured during adulthood. Associations between telomere length and adverse early life experiences have also been observed (11–13). Adults reporting physical or emotional neglect during childhood had shorter telomeres than their counterparts who did not report any childhood maltreatment (14).…”

Cosmetics use and age at menopause: is there a connection?

“…It should be noted that DNA repair mechanisms and telomere length are mechanistically related (55), and telomere length can be affected by many elements, such as telomerase activity, oxidative stress, antioxidant activity, inflammation, the hypothalamus-pituitary-adrenal axis (glucocorticoid levels), and mitochondria regulation (56). One study found that among non-Hispanic white women, one standard deviation in longer leukocyte telomere length was associated with a 0.43 year later age at menopause (57).…”

“…Most companies have made the switch over to synthesizing these colors from petroleum, but consumers have no way of knowing how the dye used in the cosmetics was synthesized, and using petroleum has its own hazards (See Petrolatum ). ** Another major concern of ethanolamine compounds is their ability to react with nitrites and form carcinogenic nitrosamines (21, 56). Nitrites can come from degradation of some cosmetic preservatives when they are exposed to air (57) and nitrites are sometimes used in cosmetics as anti-corrosive ingredients (58).…”

“…Another major concern of ethanolamine compounds is their ability to react with nitrites and form carcinogenic nitrosamines (21, 56). Nitrites can come from degradation of some cosmetic preservatives when they are exposed to air (57) and nitrites are sometimes used in cosmetics as anti-corrosive ingredients (58).…”