Total agreement with you. There have been some interesting studies out of Steve Horvaths lab (among others) on lifestyle interventions influence on epigenetic aging.
Aging - this is one such recent paper you might find interesting (Exercise and dietary influence on epigenetic aging)
Other people doing interesting studies on lifestyle change and how that may influence biological aging and longevity:
-Brian Kennedy - Exercise
-Valter Longo / Jed Fahey / Eric Verdin / Sachin Panda - Diet
As you’re suggesting, there would be great (and unique) value in crowd sourcing data for these types of interventions as long as standardized protocols can be implemented for conducting the study and collecting the data. This has generally posed many challenges in terms of experimental design for studies of this nature.
I would be super interested in participating in a decentralized trial and I think it’s a great way to get that personalized data (longitudinally) from a large cohort of individuals. Can do various online cognitive assessments for brain health, assess parameters comprising frailty index, standard blood panels, would be great to test epigenetic aging (although more expensive), can even see how that correlates to sleep, HRV, etc for those individuals that are already actively monitoring these parameters.
As you said, there’s a great deal of value in collecting/analyzing data to help us transition from the “generally good idea for you” → “this is the personalized impact on longevity for you” Would be fun to talk this out further!