Genomics, Telomere Length, Epigenetics, and Metabolomics in the Nurses' Health Studies.

Objectives: To review the contribution of the Nurses' Health Study (NHS) and NHS II to genomics, epigenetics, and metabolomics research.
Methods: We performed a narrative review of the publications of the NHS and NHS II between 1990 and 2016 based on biospecimens, including blood and tumor tissue, collected from participants.
Results: The NHS has contributed to the discovery of genetic loci influencing more than 45 complex human phenotypes, including cancers, diabetes, cardiovascular disease, reproductive characteristics, and anthropometric traits. The combination of genomewide genotype data with extensive exposure and lifestyle data has enabled the evaluation of gene-environment interactions. Furthermore, data suggest that longer telomere length increases risk of cancers not related to smoking, and that modifiable factors (e.g., diet) may have an impact on telomere length. "Omics" research in the NHS continues to expand, with epigenetics and metabolomics becoming greater areas of focus.
Conclusions: The combination of prospective biomarker data and broad exposure information has enabled the NHS to participate in a variety of "omics" research, contributing to understanding of the epidemiology and biology of multiple complex diseases.