Biological age, as opposed to chronological age, is driven by the intrinsic processes of primary aging, the accumulation of molecular damage outlined in the SENS rejuvenation research proposals, but also by the influence of the environment, secondary aging. The important contributions to secondary aging are excess visceral fat tissue as a consequence of diet, burden of infectious disease, lack of exercise, and smoking, acting through a range of mechanisms that overlap with the intrinsic processes of primary aging. There are others, but their effects are smaller and it is harder to see them in the data in comparison to the points above.

In the paper here, researchers make an effort to map recent changes in secondary aging, picking combinations of metrics from past data that might offer insight into the biological age of patients. I would say that there is little reason to expect primary aging to have altered significantly in the past few decades, given the landscape of medical technology, but it is certainly up for debate as to whether medications that control blood pressure and cholesterol levels might have some effect. They have certainly become more prevalent and effective over the time covered by the study data.

Overall this is an interesting exercise, but of little relevance to the future of aging. Gains from here on out will increasingly arise from the development of rejuvenation therapies that can repair the damage of primary aging, rather than from lifestyle improvements such as reduction in smoking or obesity, or forms of therapy that selectively, partially override downstream consequences of aging (e.g. blood pressure) without actually changing the primary aging damage that causes those problems. Greater potential gains in health and life span might be achieved through addressing primary aging; the scope of increased longevity through better lifestyle choices is far more limited. Our remaining healthy life span will thus be determined ever more by progress in rejuvenation biotechnology as time passes.