Aging
Sonia Sandhi’s Journey to a Ph.D. in Aging Research
- September 10, 2026
We caught up with Sonia just before she presented her research on sex differences on muscle aging to the annual Meeting of the Corporation. She spoke about her remarkable journey from modest circumstances in her native India to the highest levels of academic achievement, with a Ph.D. from Hannover Medical School and now, a appointment as Research Fellow to the Mayo Clinic’s research institute in Minnesota.
Q: Growing up in Punjab, was scientific research something that anyone around you did for a living? What was that world like?
Sandhi: If you know the caste system in India, I was born to a very low-caste family, and historically people who belong to this caste didn’t have a right to education. So it wasn’t a big part of the culture. And my parents didn’t have a lot of education, but as things improved a little they were thinking, ‘okay, so now we should go for that for our kids.’ They really had a big romance with education, and they let us know that you have the whole sky to explore.
Q: When did you first understand that biology and research could be a pathway for you?
Sandhi: When I got to college in Chandigarh, which is the capital of Punjab, I met a zoology teacher, Dr. Ruchira Sen, who was studying wasp behavior. She was one of a lot of people whose title said “Ph.D.,” and I was very confused why people were referring to her as “doctor” because I thought doctors were only med school people… Why is she a doctor? She’s teaching in a school, in a college, to us, and about zoology.
For me, there was no reference point. Doctors and lawyers and engineers were what we knew of. I had never been exposed to this world, to research, and suddenly I saw somebody doing these things, and I was so curious, and I felt like in all my life I had never had this much interest in something.
Plus I liked watching wasps a lot, so she included me in the work; that’s how I also ended up as one of the authors on a research paper.
Q: That path eventually led to a Ph.D. project at Hannover Medical School (MHH) and, without you quite realizing it, to Bar Harbor in November of 2021. How did that happen?
Sandhi: The project brought me to Aric Rogers and his work on aging. I didn’t know he was in the U.S., and then we scheduled a video meeting and he told me the meeting times and I thought, ‘How can he be in such a different time zone?’ It’s very accidental and very funny because I didn’t ever really think to come to the U.S., just because of how expensive it was going to be. But I still ended up in Bar Harbor, and now I just love it.
Q: Your Ph.D. thesis looks at sex differences in muscle aging, called sarcopenia, among African turquoise killifish. You found that muscle tissue in male and female African turquoise killifish age through structurally different biological pathways, while an intermittent-fasting protocol extended median lifespan by roughly 53% in males but only 21% in females. Why do these questions matter to you specifically?
Sandhi: What really interests me is how much we still do not understand about sexual dimorphism in aging. Males and females can differ in how diseases develop and progress, in the diseases they are more susceptible to, and in how they respond to treatments. Those differences can arise from sex chromosomes, hormones, reproductive biology, metabolism and the way all of those factors interact over a lifetime.
For a long time, biomedical research did not adequately account for these differences. We often treated findings from one sex as though they could automatically be generalized to the other. But we now know, for example, that males and females can metabolize drugs differently and can respond differently to the same intervention.
That is why this question matters so much to me. If the biology of aging is different between males and females, then we should not assume that an intervention that extends lifespan or preserves muscle in one sex will work equally well in the other. My work with the African turquoise killifish gives us a way to study those differences across an entire lifespan and begin identifying the biological mechanisms behind them.
Ultimately, the differences already exist in the biology. Our job as scientists is to understand them, appreciate their significance, and make sure that research and medicine account for them rather than treating them as an afterthought.
Q: The results of your most recent research, comparing muscle aging in male and female African turquoise killifish put that principle to the test.
Sandhi: What stood out was that our results, especially in females, were very different from what another lab had reported. To me, that showed why aging studies need to include both sexes rather than assuming the biology will be the same.
If we ignore sex differences early in research, we risk developing treatments that do not translate well later. Including both sexes may cost a little more upfront, but it can produce much better science.
And I do think it’s part of a larger story about gender equity. For me one of the ways to address inequality, would be through my science because that’s my language.
Q: Looking back on the Ph.D. itself, what stands out about earning it while at MDI Bio Lab?
Sandhi: I like the spirit here; that everyone here as a scientist is also helping other people to improve their science. I don’t think this project would have been possible without the collaboration of the people from MDI Bio Lab. I made a good decision coming here. I was a little hesitant in the beginning, but it turned out to be great.
Q: What’s next?
Sandhi: My postdoc is at the Mayo Clinic Department of Cardiovascular Medicine in Rochester, Minnesota. I am going to a lab that works on cardiac aging and cardiomyopathy using several different vertebrate models, including killifish. And I will continue work on dimorphism there.
Q: And on aging?
Sandhi: Aging, I think, is deeply philosophical because it forces us to ask what it means for a living system to change over time. I truly don’t know the answer, and we still don’t fully understand what it is or even exactly when it begins. Why do different tissues age at different rates? Where does aging end and disease begin, and why are the two so intertwined? Those are questions I could spend my entire career trying to answer.
The MDI Biological Laboratory graduate training program has more than doubled its ranks in three years. Just since last year, five fellows earned their doctorates while embedded in MDI Bio Lab’s research groups: Sonia Sandhi, Ph.D.; Yannic Becker, Ph.D.; Atalay Ata, Ph.D.; Blanca de Juan Mora, Ph.D.; and Sofia-Christina Papadopoulos, Ph.D.