**Danielle Gutman 1, Elina Rivkin 2, Almog Fadida 2, Lital Sharvit 1, Vered Hermush 3,4, Elad Rubin 5, Dani Kirshner 4,5, Irina Sabin 4,5, Tzvi Dwolatzky 4,5 and Gil Atzmon 1,6,\***


Received: 25 November 2019; Accepted: 15 January 2020; Published: 17 January 2020

**Abstract:** Exceptionally long-lived individuals (ELLI) who are the focus of many healthy longevity studies around the globe are now being studied in Israel. The Israeli Multi-Ethnic Centenarian Study (IMECS) cohort is utilized here for assessment of various DNA methylation clocks. Thorough phenotypic characterization and whole blood samples were obtained from ELLI, offspring of ELLI, and controls aged 53–87 with no familial exceptional longevity. DNA methylation was assessed using Illumina MethylationEPIC Beadchip and applied to DNAm age online tool for age and telomere length predictions. Relative telomere length was assessed using qPCR T/S (Telomere/Single copy gene) ratios. ELLI demonstrated juvenile performance in DNAm age clocks and overall methylation measurement, with preserved cognition and relative telomere length. Our findings suggest a favorable DNA methylation profile in ELLI enabling a slower rate of aging in those individuals in comparison to controls. It is possible that DNA methylation is a key modulator of the rate of aging and thus the ELLI DNAm profile promotes healthy longevity.

**Keywords:** healthy aging; DNA methylation; epigenetic clocks; telomere length; centenarians
