Childhood Stress Determines Testosterone Levels in Later Life
New research carried out by scientists at Durham University has suggested that the level of testosterone is largely determined by the stress they encounter earlier in life, during their childhood. This challenges the idea that testosterone production is controlled by genetics.
It seems that male adults, who spent their childhood in healthier environments and are less likely to be exposed to infectious diseases, have higher levels of testosterone later on in life. This may be due to energy trade-offs; if there aren’t many other demands placed on the body, such as fighting off infections, more energy can be directed towards producing testosterone.
Lead author of the study, Dr Kesson Magid from Durham University’s Department of Anthropology (UK), concluded that “A man’s absolute levels of testosterone are unlikely to relate to their ethnicity or where they live as adults but instead reflect their surroundings when they were children.”
But Why’s This Important?
Testosterone is the male reproductive hormone that supports masculine growth and development during puberty and enables adult males to produce sperm and reproduce. When too little or too much testosterone is produced, it can have severe implications in men’s health and fertility. For example, hypogonadism is a condition where too little testosterone is produced and has been associated include low libido, erectile dysfunction, decreased muscle mass and strength, increased body fat, decreased bone mineral density/osteoporosis, and overall reductions in vitality and quality of life. On the other hand, high levels of testosterone have been associated with prostate cancer.
Co-author Professor Gillian Bentley from Durham University commented “Very high and very low testosterone levels can have implications for men’s health and it could be important to know more about men’s childhood circumstances to build a fuller picture of their risk factors for certain conditions or diseases.”
The researchers collected data from 359 men on height, weight, age of puberty and other health information along with saliva samples to examine their testosterone levels. They compared the following groups: men born and still resident in Bangladesh; Bangladeshi men who moved to the UK (London) as children; Bangladeshi men who moved to the UK as adults; second-generation, UK-born men whose parents were Bangladeshi migrants; and UK-born ethnic Europeans.
Aspects of male reproductive function remain changeable into adolescence, up to the age of 19 and are more flexible in early rather than late childhood, according to the research. However, the study suggests that, in adulthood, men’s testosterone levels are no longer heavily influenced by their surroundings.
The research was published in Nature, ecology & evolution.