Trying to find evolution schemes depicting women. If you have one or wish to contribute, post here! #sciart #evolution (image: Eduardo Saiz)

New work looking at how epigenetic clocks and cell composition derived from Illumina EPICv1 and v2 compare, led by our outstanding colleagues @UBC @koborlab Always thrilled to publish with such a great team!.

RT @AnnaMedaris: My latest story for @AARP is live! As a bonus, I got to hang out with my editor IRL at this past weekend's @AHCJ conferenc….

RT @LifespanIO: 🧬What is the link between telomeres and aging, and why does caloric restriction appear to influence them?.A new study sheds….

Stimulating questions and great discussion on our recent paper with @eabrown18 - read more about it in her article with @NatGeo!.

More broadly, these kinds of studies are highlighting how research in biological aging has often overlooked women and women’s health: we really think more carefully about pregnancy, menstruation, and menopause, when building, testing, and validating measures of biological aging.

The effects we see are small, and we still don’t know the long-term implications. But this kind of research may one day help us identify who is at the greatest risk and devise ways to support them to minimize any long-term costs of reproduction.

Summary: Much of the work around pregnancy, health, and aging has focused on neonatal and infant health outcomes. This is hugely important work, but we need to remember to take care of moms!.

Needless to say, more work on the relationship between pregnancy and aging is needed! Good news is the NIA is aware and is taking this seriously.

What we don’t know is the extent to which the sped up epigenetic aging associated with pregnancy returns to baseline, what the long-term implications of these changes are, or if some pregnancies (such as among young mothers) are more costly than others.

The idea that biological aging is sped up during pregnancy is getting to be well-established: We observed this in our study, as did Poganik et al. and Pham et al, in their recent papers in Cell Metabolism.

We did not find any relationship between number of pregnancies a man reported fathering and epigenetic aging, suggesting it might be the direct investment into gestation and/or breastfeeding that drives accelerated epigenetic aging in our study.

In our final analysis, we examined the relationship between number of pregnancies fathered and epigenetic aging in same-aged cohort men (n=910). This helps us further get at potential social factors tied to early life fertility (or sexual activity) and biological aging.

Using conservative estimates from our longitudinal analysis, we estimate the effect of each pregnancy to be about 2.4-2.8 months of biological aging, which based on a meta-analysis of Chen et al. amounts to a 0.5-0.8% increase in mortality risk.

In this analysis, we found that changes in pregnancy number between baseline and follow-up were associated with changes in epigenetic aging according to 2 of the 6 epigenetic clocks - both so called ‘first-generation’ clocks that are trained to predict chronological age.

To further control for social and environmental factors, we followed a subset of women (n=331) and looked at reproductive history and epigenetic aging at a 2nd timepoint 3.5-9y later. This allows us to compare how changes in pregnancy number relate to changes in epigenetic aging.

We found that women with a history of pregnancy (regardless of the outcome) looked biologically older according to all clocks than women who had never been pregnant. We also found that women with more pregnancies looked biologically older than those with fewer pregnancies (n=825)

We measured biological aging using 6 epigenetic clocks, a family of revolutionary tools for studying aging and predicting health and longevity. You can read more about them in my not too out-of-date review article.

To do this, we studied n=1735 young (20-22y old) men and women participating in the Cebu Longitudinal Health and Nutrition Survey (CLHNS), an ongoing, long-term study of growth, development, and health in the Philippines.

We previously showed that parity was associated with biological aging among post-menopausal women. Here, we asked if it is possible to detect these ‘costs of reproduction’ among young adults, decades before they start to show signs of disease or mortality.

Research in plants and animals generally supports this hypothesis, as do large epidemiological studies showing higher risk for some diseases and all-cause mortality, especially at the high end of fertility and among younger mothers. e.g. Zhang et al. 2016.