Sigh. Correlation. Causation. No mechanism is offered, and all they studied was respondent's reported diet. Nothing to see here, other than the fact that there is evidence that eating lots of fresh produce correlates well with longevity. Really? Thanks, Mr. Scientist! Do both of those things also correlate well with upper middle class?
The problem with people like you who have this Pavlovian conditioning of belching out "correlation != causation!!!!!1" whenever an observational study is mentioned which doesn't affirm their own preconceptions is that they seem to be incapable of understanding that it is practically infeasible to run randomized controlled trials to study the interactions between complex lifestyle factors such as diets and complex diseases such as cancers and CVDs, as you would have to somehow ensure sufficiently high study compliance in a sufficiently large sample over a sufficiently long period of time, i.e., decades; not to mention ethical implications.
What "people like me" do you mean? Those who don't forgive you for doing bad science just because good science is hard? Yeah, those guys will totally fuck up a neighbourhood.
By "people like you" I mean people like you who go to social bookmarking sites, don't bother to properly read the article, state the (in this case: scientifically) obvious, mix in some ignorance about the topic at hand and then lean back thinking they had contributed anything insightful. In short, by "people like you" I mean the peanut gallery.
They do say that they controlled for class and physical activity: but the only thing open-access about the article is the abstract, so I can't tell how they controlled for those things.
The controlled for them in the standard way, by adding them into the (Cox) regression. The full list of controls is:
"Other variables included in the analysis were age (35–44 years, 45–54 years, 55–64 years, 65–74 years and 75+ years), sex, smoking status (current smoker, ex-regular smoker, never smoked regularly) and social class of the head of household (manual, non-manual, other). Education (degree or equivalent qualification, other, no qualification), measured body mass index (BMI) (<20 kg/m2, 20–24.9 kg/m2, 25–29.9 kg/m2, ≥30 kg/m2), physical activity (as maximum activity intensity level in the past 4 weeks: inactive, light activity, moderate activity, vigorous activity) and alcohol consumption on heaviest drinking day in the previous week (non-drinker, drank within limits, drank above limits, drank more than twice the recommended daily limit) were also added to the models as indicated."
The most obvious thing missing from this list to me is all other dietary related variables. For example, people who like the taste of plants are probably far less likely to enjoy eating red meat, salty foods, and many other things that have been associated with increased mortality.
>For example, people who like the taste of plants are probably far less likely to enjoy eating red meat, salty foods, and many other things that have been associated with increased mortality.
Which, incidentally, have really only been associated with increased mortality through flawed epidemiological studies such as this one.
Flawed is a strong word. There is little doubt that meat and sodium intake are associated with a number of poor health outcomes. (Run almost any regression you can think of.) That is a much weaker statement than saying the former causes the latter, which is why responsible researchers are reluctant to do so unless there is very convincing evidence. Even if you are not convinced of the causal link, you would be well served to moderate your consumption of these foods on the chance that one exists.
>social class of the head of household (manual, non-manual, other). Education (degree or equivalent qualification, other, no qualification)
Social class is manual/non-manual? What do retail and telemarketing count as?
edit: I'm being a bit pithy here, but what I want to know is if someone who went to DeVry and works in telemarketing ends up higher class than me, a six-figure college dropout with six-figure college (Northwestern/Northern Illinois) graduate parents.
Social class is almost fully determined by the wealth of people's parents, why don't we use it?
The problem is that people have been saying that fruits and vegetables are good for you for a long time, so conscientious who exercise and go to the doctors and take the medicines they're prescribed will also disproportionately eat more fruits and vegetables. With health, the conventional wisdom is the hardest thing to test and is where you really need controlled trials, or at least natural experiments where people eat more or less vegetables for extrinsic reasons.
Mod to high SES is correlated with eating healthier food, we all get that. However, by convincing low SES to eat healthier, you can actually increase their SES. For example, if you eat better, you are healthier and therefore take less sick days at work. If you don't get paid for sick days, this means more money in pocket. Showing up for work more may increase your chance at a raise or promotion and therefore increase your SES.
So I think there is value in these studies. As well, food diaries are a standard measure of diet. Not ideal, but accepted standard.
I think SES is just a very poor proxy for IQ. Higher IQ people are a lot healthier than lower IQ people regardless of SES. Probably quite a bit of that is just genetic (mutational load lowers both IQ and general health) and diet details are secondary.
These observational studies are mostly worthless because they are not controlling for the right things.
> and all they studied was respondent's reported diet
If you read the actual journal article referenced [1], a number of other factors were included in the analysis, and the stated effects were after controlling for those factors (which included smoking, age, and social class, among other factors.)
A valid criticism. I was basing my response on the originally linked article from Science Daily, not on the cited study. Notably, the original article also doesn't make the egregious causation claim that irritated me so in the linked report.
Ah, food studies. The breeding ground of bad science.
I am not saying this is bad science, but a quick glance shows this to be survey data.
The problem with the data is that people who eat "healthy" probably care more about their health. Even if the food has a negative effect, they could have other tendencies (exercise) that outweigh any negatives.
Plus they probably eat more carefully, in general, drink less, etc.
So... correlation != causation yada yada
A better study would be to take unhealthy people and now introduce the fruits and veg and see what happens.
You might be correct, but I've seen a lot of smart people fall into this trap: "X is not proven to be true, there for X is false". The study might not prove any hard facts, but it doesn't mean the point of the study isn't spot on.
On a technical sidenote, 65226 people were in the study. Who wants to bet that the count was limited by the number of rows that fit in an old excel spreadsheet?
I doubt its quite so straightforward. If you eat less veggies and replace them with doughnuts amd beer then im sure you're probably more likely to die sooner. Replace them with organic pastured meats, particularly organ meats, then Im not so convinced.
There is much more to health than the amount of vegetables you eat, including genetics, and it is imposssible to properly test them in isolation.
Don't you just love statements like "and canned and frozen fruit appeared to increase risk of death by 17% per portion" - I could be dead by nightfall.
I do look forward to a proper statistical analysis of these results rather than this tabloid nonsense. It will be interesting to see if there is actually any measurable impact above (say) just some fruit or vegetable intake per day.
Your risk of death is already, probably really really low, so increasing it by 17% isn't going to kill _you_. It will kill the other you out in statistics land, which could actually be me, so do a bro a favor and watch what you eat.
So if you have a 0.004% chance of dying on any given day, and you increase this by 100%, then you have a 0.008% chance of dying. Not a 100.004% chance.
Eating 500+ portions of fruits and veggies a day reduces your risk of death by 99.99%. Because you are far less likely to get into any accidents if you are so busy eating fruits.
I searched on the Internet and couldn't find it either. I also don't have access to this paper so I can't check. Can anyone clarify why they don't use something standard like grams? Nobody else seems to have the question so I assume it's just something standard that we aren't understanding.
This isn't very valuable with out the full questionnaire visible. Most of these kinds of "studies" come from huge questionnaires. If you ask enough questions then your statistics will show a strong link between something.
I have a much stronger dislike for comments like this. Obviously nothing will decrease your risk of death as time stretches toward infinity, so why bother pointing that out? "Hey guys, I chose to interpret this to mean something obviously wrong and it was wrong" isn't at all revelatory.
The article even explicitly says "at any point in time" in the very first graf. The fact that the entire article isn't packed into the headline is also not all that revelatory.
> The title and the abstract are poorly written and the GP is deriding it which his perfectly appropriate.
Without criticizing it for not including more information (which, again, is not the point), what is poorly written about the title? I wouldn't say it's a work of art, but it seems serviceable to me. It's not deceptive, offensive or so vague you don't know what to expect.
> Not only that, after reading it, it appears that the science is bollocks too.
There are certainly valid and substantial criticisms you could make along those lines. That is one of the many reasons I feel like deliberately misinterpreting the title and criticizing that incorrect interpretation is a poor use of time and space.
I think you believe I'm supporting the article as a piece of great science. I'm not. I'm saying that nit-picking titles does not constitute meaningful criticism and doesn't increase our collective understanding of the article one iota. I feel like every science article includes some "Well, actually…" comment about the title that doesn't actually make anything more clear. I'd rather see more people tearing articles apart and fewer sarcastic comments about titles.
Risk of death is actually a pretty common medical term IIUC. It is obviously a risk over a period of time with two end points, not over the half-line from now to infinite-future, because the second interpretation makes zero sense. It's not useful to point out that common and well understood terminology isn't perfectly precise.
Not at any point in time, you don't. You increase your risk of those things as t=∞ (because previously you might have died before they could happen), but your risk of those things does not increase at any point in time.
Fair point, but I do appreciate stories that have to do with health of the human body as it lends to the idea of body hacking and performance tuning. If you peruse around, there's a lot of HN contributed stories and comments having to do with concepts of mixing in exercise and healthy eating habits to minimize lethargy and burnt out symptoms and maximize energy and life balance. (Hopefully no citations needed)
