The confounding variables cut in every direction, so that is always an issue. But extrapolating recommendations for supplementation adds yet another layer removed from the evidence, which is even more problematic than the diet recommendation itself. In addition to any vitamins we may identify in foods (some of which may not be typically found in supplement form), there are other factors: fiber content, displacement of less healthy foods, etc.

The issue with that sort of approach is that it basically begs for the Hawthorne effect. Is it really the diet that is making these people healthier or is it that fact that people who actually care about their diet enough to think about eating healthier tend to lead a healthier overall lifestyle (exercise, etc)?

@sonic:

I am very aware of the chirality of molecules. It is a basic principle that is hammered into you during organic chemistry in undergrad. And in fact, it is not just that the chirality is important – it is downright necessary. D-glucose is readily utilized by the body, but L-glucose is not. Enzymes (for the most part) have a very significant amount of specificity such that they cannot act on different enantiomers.

However, there are ways to purify a supplement to contain only the proper enantiomer and even if it is racemic (contains both), then all you need to do is double the dose.

So chirality, or handedness, can’t really be the issue here.

As for the flavinoids – I’ll admit I am reasonably ignorant on the topic, but from what I do know that also doesn’t really have a bearing on it. Unless you can cite some data which demonstrates one needs flavinoids to absorb vitamins and minerals – which I think is highly unlikely based on how we treat such deficiencies in CF patients. Once the vitamin makes it into circulation and assuming it is the correct enantiomer, the body can’t possibly differentiate whether it came with or without a flavinoid or from an orange or a tablet. The question, as far as I know it, must be a bit deeper and lie in the gut somewhere – if it exists at all.

As for the bacteria – they don’t exactly regulate our vitamin intake. They can most definitely affect it, but they do not act in a concerted symbiotic fashion to make sure we don’t get too much or get enough. They synthesize vitamin K for us and we take it and utilize it as needed. Beyond that, they can indeed prevent vitamin absorption in certain cases (usually pathologica states that globally decrease intestinal absorption capacity) and do play a role in overloading us with ammonia, but that is about it. In other words, they do not release only those vitamins that we need at the time.

As for your friend’s farm – I never said it was easy to get certified organic, but that it doesn’t really mean all that much vis-a-vis what most people think it means. But I am also under the impression that there isn’t a single uniform “organic accreditation” committee or standard and that foods can say “organic” and actually have that mean different things depending on exactly where it comes from. I could be wrong on this – I haven’t researched it in depth. But if you have some links that summarize exactly what it does mean and delineate if there is a uniform standard or not, I’d be keen to peruse them.

The handedness of the molecules might be of importance– there are a few studies I’ve read that indicate they are.
But it is the flavonoids that are really important IMO. That is because our digestive systems will not use vitamins with the flavonoids attached unless the vitamin is released by a bacterium in the digestive system.

It appears the bacteria in our digestive systems regulate which vitamins we actually get by releasing only those needed at the time.
It seems taking vitamins without flavonoids can lead to various imbalances due to the bypassing of this system.

BTW–The term ‘organic’ is meaningful in the US– it doesn’t mean what many of the farmers lobbied for- but it is meaningful none the less. (My friend recently tried to get his farm certified– not so easy after all…)

Well, my understanding is from a different angle, and the way you are asking the question is the reverse from the way I think the problem lies. The issue seems to be a problem of attributing the “benefits” of a healthy diet to specific vitamins in foods. For example, lets take a body of research that people who have a diet high in fruits and vegetables have lower rates of diseases x, y, and z. Lets assume for the sake of argument that this is a causal relationship. It does not follow that we can simply use a supplement that contains those vitamins found in those foods to replicate results of that diet, but that is where the thinking goes beyond the evidence. This is not a new issue, but I’ve noticed this problem with “antioxidants” more recently… assuming that the theoretical explanation is the whole story when it is an oversimplifcation that makes it incorrect

A refinery pumping carcinogens into the atmosphere is as natural as an ant hill. The natural world has produced both of them.

You forgot the big one – Fat free!

When it comes to supplements as you pointed out CCBowers, that is hit or miss for me. I don’t try and engage people in it too much, unless I think that there is distinct and direct possibility of harm (like the HCG diet or using nasal spray Zicam). However, one personal anecdote is that not terribly long into dating my current girlfriend, I was helping her move out of her place and found she had a gigantic bottle of echinacea. I didn’t want to start anything so I just said “I don’t really think this is worth spending money on, but if you want to go right ahead.” She got a little upset and told me that her doctor had said it was useful and she’d been using it for years and it made her colds feel better. My response was to the effect that I didn’t think it would hurt anything, it’s her money to waste if she wants, and that her doctor may not be hip to the newest data showing it really doesn’t do anything. That was about it.

Two days later she comes up to me and says she needs to apologize and thank me. Huh? Turns out she sat down and did some research and discovered I was right. Here’s the kicker – she actually did a PubMed search and found the same 2005 article that I thought was a pretty good clincher on it. She then did something very few people ever do – she changed her mind based on the evidence. And gave the bottle of echinacea to her very fun and cute yet hippie-ish dancer/pilates instructor roommate. LOL.

Needless to say, she is still my girlfriend. So yeah, the whole Dr. Oz’s wife thing – I picked better (BTW – she is an aerospace engineer, not a medical scientist, so I was doubly impressed she did a pubmed search, read, and undertsood the articles).

Anyways, I am also curious about the apparently better absorption of vitamins and nutrients from foods vs pills. I really don’t know much about it, from an evidence based perspective. But it has been “common knowledge” that this is the case. Me being who I am feels that there must be some sort of actual explanation and MOA for it. Perhaps it has to do with digestion in general? What if you take in foods and pills at the same time vs pills alone on an empty stomach? Is that where the discrepancy lies? I don’t know – just spitballing, but I’d be curious if anyone here has any actual data or other ideas.

I am amazed that we don’t have more definitive answers about this especially considering how much money is spent on food. The comparison in studies should be between washed organic and nonorganic produce. Since the vast majority of people wash their produce what is the point in knowing the prewashed pesticide content? Then again if we find a difference we will have to decide if this difference is meaningful. (In general, I do have a problem with the term “organic” and its definition, because the naturalistic fallacy is built into the criteria, but I am realistic in that the term is here to stay)