Calen Patrick Ryan, PhD

Assoc. Research Scientist and Lead Data Scientist - Robert N. Butler Aging Center - Columbia University Mailman School of Public Health


Office: #414

722 W. 168th Street

New York, NY 10032

I study the effects of reproduction and stress on health and biological aging. To do so, I use high-dimensional epigenetic data and computational statistics to examine the molecular processes that can tell us about the aging process.

Much of my work over the past decade has been carried out in the Philippines with the Cebu Longitudinal Health and Nutrition Survey (CLHNS). More recently, I have applied the same tools to study epigenetic processes in other large, longitudinal population studies, as well as randomized-controlled trails of geroprotective interventions, such as caloric restriction.

My research is situated at the intersection of evolutionary biology, medicine, and public health, and has received support from institutions such as the National Science Foundation (NSF), the National Institute on Aging (NIA), the National Institute of Environmental Health Sciences (NIEHS), and the Natural Sciences and Engineering Research Council of Canada (NSERC).

Our findings have been featured in popular media outlets, including The Washington Post, CNN, NBC, and Time Magazine.

Click here for his full CV.


Apr 8, 2024 Our publication showing that pregnancy is associated with faster epigenetic aging is out now in PNAS! Lots of press on this one, including Time, National Geographic, and The Washington Post, among others! Find the article here.
Jan 12, 2024 I recently had the opportunity to speak to the interesting, eclectic, and engaged group of folks at the Foresight Institute about our work on Caloric Restriction and DNA methylation measures of Biological Aging. Click on this link if you are interested in hearing more.
Feb 9, 2023 My paper (co-led with Dr. Reem Waziry) is now out in Nature Aging! We studied the effect of calorie restriction on biological aging humans in a first-of-its-kind randomized controlled trial in healthy, non-obese adults. The headline finding is that two years moderate calorie restriction slowed the pace of biological aging as measured by the DunedinPACE DNA methylation clock. Click here to read more!
Feb 24, 2022 I have a new article in Evolution, Medicine, and Public Health - DNA methylation analysis reveals epigenetic shift toward risk for metabolic disease, cervical cancer, autoimmune disorders during pregnancy and recovery to pre-pregnancy risk postpartum. For an overview, check out the Twitter thread!
Nov 25, 2020 New paper with Talia Shirazi, Waylon Hastings, and Asher Rosinger looking at parity and composite measures of biological aging is now out in Scientific Reports! Super cool findings that are helping us understand costs of reproduction and women’s health Click here to check it out!

selected publications

  1. breastfeeding.jpg
    Immune cell type and DNA methylation vary with reproductive status in women: possible pathways for costs of reproduction
    Calen P. Ryan, Meaghan J Jones, Rachel D Edgar, and 4 more authors
    Evolution, Medicine, and Public Health, Jan 2022
  2. nature_aging_ryan.png
    Effect of long-term caloric restriction on DNA methylation measures of biological aging in healthy adults from the CALERIE trial
    R. Waziry, Calen P. Ryan, D. L. Corcoran, and 19 more authors
    Nature Aging, Feb 2023
    Publisher: Nature Publishing Group
  3. PNAS_temporary.png
    Pregnancy is linked to faster epigenetic aging in young women
    Calen P. Ryan, Nanette R. Lee, Delia B. Carba, and 6 more authors
    Proceedings of the National Academy of Sciences, Apr 2024
    Publisher: Proceedings of the National Academy of Sciences