Partially funded by entity related to manufacturer of daily multivitamins. Study was in people over 60 average age 70 if I recall. I didn't care enough to look, but the question I'd ask is how were the people who died during the study accounted for in the "biological aging testing?"
From Harvard: https://news.ycombinator.com/item?id=47319478
Nature: https://news.ycombinator.com/item?id=47325135
sci.news: https://news.ycombinator.com/item?id=47354653