Does this study take into account other variables? The article also says that people who do not drink milk have shorter telomeres. Could it be that people who

Does this study take into account other variables? The article also says that people who do not drink milk have shorter telomeres. Could it be that people who drink 0% and 1% milk also eat fewer foods high in fat and sugar (or are more aware of their diet in other ways) compared to the average (i.e., those who do not drink milk and those who drink the most common milk available)?