INMA: “Do sedentary behaviours affect the length of telomeres in childhood?”


Our colleague Daniel Prieto has recently published the following scientific article with information from the INMA Study: ( in which the relationship between sedentary behaviours and the length of the telomeres is explored.

But what are telomeres? Telomeres are structures found at the ends of chromosomes, which are made up of DNA and protein sequences. These telomeres act as “plugs” which protect the genetic material of the chromosomes and prevent them from deteriorating. As our cells divide, telomeres naturally shorten, contributing to the aging process. The innovation of this work is to verify the effect of sedentary behaviours on the length of telomeres.

Sedentary behaviours, downtime in front of the television, video games, etc., during childhood can have negative effects on the health and well-being of children. In particular, there are studies that have shown that more time dedicated to sedentary behaviours in childhood influences having less muscular development, less concentration and poorer academic performance, as well as affecting their interaction and socialization skills. In addition, scientific evidence has observed that more time dedicated to sedentary behaviours in childhood can influence having more obesity, cardiovascular problems, type 2 diabetes, and anxiety and depression in adult life. Regarding telomeres, sedentary behaviours could contribute to accelerate their shortening due to their oxidative and inflammatory action on the cells of our body. However, to date no studies have been carried out to see if sedentary behaviours influence telomere length in childhood.

Thanks to the participation of 669 children from the INMA Study who gave a blood sample and answered several questionnaires at 4 years of age and 530 children at 8 years of age, this manuscript has been possible. These blood samples allowed us to determine telomere length at 4 and 8 years and with these measurements we were able to calculate changes between 4-8 years. In addition, at the follow-up visit at child’s age 4, information was collected on the sedentary behaviours reported by the parents. Specifically, screen viewing time (television, videos, etc.), other sedentary activities (puzzles, reading, homework, etc.) and total time (the sum of these two) were calculated. These variables were transformed into three levels of sedentary behaviours (low, medium or high level).

The results obtained showed that children who spent more time viewing screens at age 4 (highest level, between 1.6 and 5.0 hours a day) had a telomere length 3.9% shorter compared to children at the lowest level (between 0 and 1.0 hours per day). In addition, these children exposed to more screen time at age 4 showed a greater acceleration of telomere shortening. This study corroborates the potential negative effect of sedentary behaviours during childhood with respect to cellular longevity and focuses on the importance of promoting an active lifestyle from an early age to promote the health of children.

If you want to know more about telomeres, you can consult the following informative video:

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Reference: Prieto-Botella D, Martens DS, Valera-Gran D, Subiza-Pérez M, Tardón A, Lozano M, Casas M, Bustamante M, Jimeno-Romero A, Fernández-Somoano A, Llop S, Vrijheid M, Nawrot TS, Navarrete-Muñoz EM. Sedentary Behaviour and Telomere Length Shortening during Early Childhood: Evidence from the Multicentre Prospective INMA Cohort Study. Int J Environ Res Public Health. 2023 Mar 14;20(6):5134.

Link to the scientific article: