Carrying a baby creates some of the same epigenetic patterns on DNA seen in older people.
Aches and pains aren’t all that pregnancy shares with ageing. Brewing a baby leads to changes in the distribution of certain chemical markers on a pregnant person’s DNA — changes similar to those that are a hallmark of getting older. But new research shows that, several months after a person gives birth, the chemical patterns revert to an earlier state1. The results strengthen previous work in mice and preliminary results in humans2.
It’s not surprising that pregnancy takes a toll, but the reversal was “somewhat unexpected”, says perinatal-health specialist Kieran O’Donnell at Yale University in New Haven, Connecticut, a co-author of the study. It was published on 22 March in Cell Metabolism.
I agree with both of them. I think DNA methylation markers have some significance, but they are a marker of a status and the status relates to gene expression. However, that depends on a number of factors. The core of aging, however, also drives gene expression (mitochondrial problems - heteroplasmy, and senescent cells leading to problems with acetyl-CoA in the nucleus and difficulties with translation).
These markers, like most markers in health, have to be trended over the long haul. We can make drastic changes in the short term and see the positive effects in key markers. But then they need to be kept over the years and decades. The pregnacy birth is analogous of this. You can turn all your habits towards health or unhealth and flip them at a later date by changing back.
I’d say this questions the validity of short term use of aging clocks. They clearly are easily manipulated, purposefully or accidentally. Long term is a better reflection but I still question the validity.
The reversal isn’t complete from what I understand. Women with no children seem to have better / younger markers than mothers, all things equal, and the more kids the worse (including by telomere length measurement). At least in modern western societies. I’m pregnant with my 5th and can attest that it’s no walk in the park. Thymus involution alone is definitely an accelerated aging of the immune system that happens during pregnancy— and gets reversed afterwards. I feel like I’m getting a taste of what it’s like to have the immunity of someone in her late 60s and it’s not pretty. Every virus and bacterium zeroes in on me and wipes me out whereas when I’m not pregnant I almost never get sick. Heart rate is up a lot, HRV down, wounds take longer to heal… again probably some of the aging captured by the measures they use is mostly immune related. It wouldn’t surprise me if there’s genuine long term acceleration of aging as a biological tradeoff for having completed reproduction — those who haven’t might have activated gene expression mechanisms trying to give them some extra runway to make up for lost time. Our inner biology considers our individual bodies as completely disposable. It’s only a certain part of our brain that gives a damn about living longer / forever.
A great example of why I question the clocks. Your 5 pregnancies may make the clocks show you to be older, but the pregnancies have cut your risk of breast cancer in half.
There was some discussion of that in the literature as in primitive communal societies where women in a village or extended family raised kids collectively and got a ton of help, it was the mothers who actually seemed to have better / younger markers than the “old maids,” age and all else equal.
So I am not sure.
But when longevity bros talk of hormesis and stressors for rejuvenating the body, heat stress and exercise stress and food availability (in the context of fasting) stress, I have to chuckle. If they were to put their money where their mouths are, hell, they’re missing out on pregnancy stress. This shit busts up your body real good.
Yes and that sounds impressive at first blush but the devil’s in the details. My familial risk of breast cancer was almost zero based on the medical history of my ancestors going back at least three generations. So half of nearly zero isn’t going to move the needle much. But say if I were someone higher risk, it would have mattered more.
The biggest positive side effect to many full term pregnancies seems to be delayed onset of menopause—the eggs that would have been shed during menstruation were spared when menstruation was on pause during pregnancy and breastfeeding (for me nearly a decade somehow—gulp) so I most likely have a much better ovarian reserve than a 37 year old who never had kids. Getting pregnant at the drop of a hat and staying that way seems to confirm that. Most women I know who started having kids in their 30s had to deal with quite a few miscarriages or had to wait to get pregnant in the first place—lots of trying. I never had any of those issues but I wonder if it has to do with starting youngish at 25. So now even in my 30s the arrested cycles of menstruation have left my ovaries in a better state.
I plan to get back on Rapa stat as soon as I wean the new baby because as a woman of my age, the most promising life extension effect of rapamycin is probably its potential to delay menopause by quite a bit. That’s when things go downhill fast for us.
I think they’re probably of very little value. It’s why I never use them myself — seem like a way to fool oneself into a sense of achievement for “scoring” younger. I think blood markers are of obvious value but the clocks are probably junk at this stage. Doesn’t mean the conclusion is erroneous— I could see ways in which pregnancy might accelerate aging and even evolutionary reasons for it doing so. But who knows. At any rate it’s not deterring me from having a rather large family.
That was supposed to be a joke…but I guess for the primary caregiver, it’s no joke.
“I aged 30 years in 15” says Maria de los Angeles - author of the new book How to Double your Aging Speed with Five Kids or Less “and my GrimAge test proves it!”
