# Arizona State University studied DNA methylation in 894 dogs to explain shorter lives of large breeds

- Published: 2026-11-13 07:01 UTC
- Section: Life & Health › Biology & biochemistry
- Tags: dog lifespan, small and large breeds, DNA methylation, LINE1 elements, jumping genes, epigenetic ageing, Arizona State University, Blaise Mariner
- URL: https://realtech.media/news/rt-3e7af4c2b3e8b5624088f811_arizona_state_university/

**Researchers found that DNA methylation, especially in LINE1 elements, declines with age in dogs; they suggest this may explain why large breeds age faster.**

![Arizona State University studied DNA methylation in 894 dogs to explain shorter lives of large breeds](https://realtech.media/media/2026/11/5b50ab263defb1c8.jpg)
*cursorinfo.co.il*

Researchers at Arizona State University analysed DNA methylation in 894 dogs to find out why smaller dogs tend to live longer than large ones, cursorinfo.co.il reports. [1] Lifespan varies widely by breed: some dogs live less than ten years, while others under favourable conditions reach 25. [1] In general, the smaller the dog, the higher the chance it will live longer.

## Why size matters for lifespan

Among mammals, larger species usually outlive smaller ones. Within a single species, including dogs, the pattern can reverse. Large dogs mature faster, more often meet age-related diseases and on average live shorter lives. [1] The molecular reasons for this dependence have so far been studied insufficiently.

## Methylation and LINE1 elements

DNA methylation is an epigenetic mechanism that regulates gene activity and serves as one of the biomarkers of ageing. [1] In the 894 dogs, methylation declined with age, most strongly in LINE1 elements, known as "jumping genes". [1] These elements can move around the genome and damage DNA, and methylation normally restrains their activity.

The researchers suggest that these processes may explain the differences in lifespan between dogs of different sizes. [1] Co-author Blaise Mariner said that weaker control over jumping genes may be one molecular mechanism of faster ageing in large dogs. [1]

The scientists allow that a similar process affects ageing in other mammals, and that acting on these DNA elements could in future help extend human life. This remains a hypothesis of the authors: the material describes an observed decline in methylation with age, not an intervention.

## Sources

1. [cursorinfo.co.il](https://cursorinfo.co.il/interest/pochemu-malenkie-porody-sobak-zhivut-dolshe-krupnyh-issledovanie)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-3e7af4c2b3e8b5624088f811_arizona_state_university/