Just opened the study and read a bit about the methods and I wonder why they didn't include people that do not drink milk so the telomere lengths could be compa

Just opened the study and read a bit about the methods and I wonder why they didn't include people that do not drink milk so the telomere lengths could be compared. We cannot know if milk (in general or 1%) is causing aging or protecting against it, cases which point for very different conclusions. This table also has something interesting that corroborates with this idea: https://new.hindawi.com/journals/omcl/2019/1574021/tab4/ https://new.hindawi.com/journals/omcl/2019/1574021/tab4/ Note how the ones that rarely drink any milk have the same telomere lengths, same as the ones that drink full fat or 2% milk. SE is also so big for 1% and non-fat on the "rarely" row that telomere lengths can be considered to be the same for all the columns (on this row). It makes me wonder if it's the milk or if there is any other covariable that is playing a role here. In fact, they themselves cite this in the study ("Discussion" section): "However, it is possible that other dietary differences account for some of the biological aging differences among the milk fat categories." Therefore, I'd take this study with a grain of salt. If anything can be concluded by these numbers is that 1% milk may be protective, not that full-fat milk promotes aging.