Green leafy vegetables reduce Diabetes risk.
Well would that it was true. If it was certain I would for sure be dancing a jig (not a pretty site). But hold the front page, because I'm pretty sure that this observational study, sadly does not really prove any causation. There was much hype on the Today programme (a much admired breakfast radio programme), which pretty much allowed 'Arnold spokesperson' for said University to say what they liked, in support of this study. Including of course the inevitable conclusions that eating 'five-a-day' was good for us and should be part of a 'proven' lifestyle agenda. If one actually reads the study, or rather the extract, because you can only read the full study by buying it, the only reference to fruit and vegetable consumption was to say that NO significant benefit accrued.
This study I use as an example of the virtually worthless research that is being undertaken with my money to prove something that some pompous Medic thinks might be true, but can't really prove even when they have done the study. It is an established fact that the brassica family are a useful source of vitamins and minerals and even anti-oxidants. How much protection these can impart is still somewhat in conjecture, although it is some. What is proven, even by this study is that fruit and vegetables generally or even in isolation do not impart any protection against Diabetes. Earlier studies have proven that fruit and vegetable consumption imparts little, to no protection, from cancer and heart disease (see posts passim). The protection that is claimed in this study was of a 14% reduction in the risk of becoming diabetic; not a huge amount one might say but nonetheless worthwhile. And, whilst I am convinced that leafy greens are good for you, I do not feel that this rather poor study does anything to advance the cause of that particular food group because it has been linked to an opinion about fruit and vegetables that is not evidence based.
I quote from the study,"The summary estimates showed no significant benefits of increasing the consumption of vegetables, fruit, or fruit and vegetables combined". So why then did Prof. Davies state in her interview that eating 'five a day' was intrinsic to good health and implying, as a consequence that it was proven by this study, by association? Her own data actually states the contrary. She is then advocating once more, the unproven, even dangerous ( for diabetics and the obese) advice that we should eat fruit and vegetables in abundance. Root vegetables, most fruits and potatoes in particular contain an abundance of carbohydrates and fructose. Sucrose (table sugar) is made from root vegetables. Fruits are made into 'smoothies', those appalling thick concoctions of fruits that allow all '5 a day' to be condensed into a small bottle. So that busy people can get their 'health fix' in one shot. This is madness! Feeding this, as medically sanctioned nutrition, for diabetics is madness. Telling fat people to do this is likely to make them fatter and could push them into NIDDM. This is from a Professor of Diabetes Medicine! (Whatever that means).
This is I feel indicative of the way that so much scientific endeavor is now going. Producing endless meta analyses (studies of studies), vast databases of observational material that is nothing more than correlation. Remember 'correlation (and observation) does not prove causation. It can provide one with the hypothesis upon which to conduct a proper trial. But it proves little else other than association. One astounding element is that at no point was the Professor was questioned by the journalist about this statement. Do journalists no longer do any research about the subject of their interview? Or they all part of a conspiracy to subvert the truth? Well probably not. Just p**s poor at the job. Come back Paxman wherever you are!