How Lifestyle Studies From Harvard Help Shape Public Health

but I will address the health professionals follow-up study and and I’m sure David knows a lot more about this than I do but this is a study that that is a sort of a partner study to to the Nurses Health Study which was on about 280,000 women there were three cohorts one in 76 one in 89 and one in 2010 and they’ve been followed for many years and the health professionals follow-up study was about fifty thousand men and again following to see who develops what based on various lifestyle choices and both of these studies have been also combined in a number of of write-ups and I can tell you this is not one study these are literally thousands of reports based on these cohorts and these cohorts have informed nutrition policy and and the the outcomes have been really quite profound so we’ve learned a lot about how smoking impacts health how alcohol consumption impacts health why we need to eat more fruits and vegetables and and why red meat and processed meat may be damaging or at least that they are damaging and so and sugar and and so on so so these are I think are very important studies because they’ve given us information about very large populations and and what protects health and what doesn’t and they come from Harvard as as you probably know and you may want to add a little bit onto the good answer Brenda and yeah just a little bit so the question was why do we like it I don’t know who said we did like it or if we all do like it but if we like it I think you know the issue is there is no well let me ask you something anybody do carpentry or use tools of any kind is there any one tool that’s right for every job and anything you can think of right science is the same so methodology and science is a toolkit and the best way to answer a given question is the tool that’s matched to the question the tools of science or different way of asking and answering questions so I what I like about the health professionals follow study the Nurses Health Study other large cohort studies is they provide a view from altitude you’re never going to get with a randomized control trial so we should get the answers we can from our CTS but what happens to large populations over 30 years and more you can’t randomly assign people to eat different ways for the next thirty years nobody’s willing to play so what I like is they populate an important gap they provide the view from altitude

I think when we’re telling you what we like about methods it’s also important to acknowledge limitations and and one of the concerns about cohort studies is they’re not as good at proving cause and effect they show association now sometimes that’s the same as causality sometimes it’s not it’s important to distinguish and the other issue is and there’s some legitimacy here it’s too bad Walter will it’s not here because maybe he would argue effectively against this but there is the concern of so-called data dredging so we’ve got a hundred and fifty thousand people we’ve asked them about all kinds of things for 30 years we can test any hypothesis Under the Sun maybe we’re interested in the correlation between your favorite color and athlete’s foot and we find in our data set that you know people who like chartreuse tend to be particularly prone to athlete’s foot who cares right so there’s the risk of hey we’ve got a huge massive data we can ask it anything and some of what issues from that and this is a perennial concern in epidemiology can be absolute nonsense the best way to safeguard against that is to make sure that you’re posing good sensible defensible questions in the first place and that the association’s you’re exploring are supported by other kinds of evidence and are mechanistically plausible when the health professionals follow-up study is used that way and it usually is it’s a tremendous asset