My main point is not that one should depend on carrots to give one an entire daily requirement of calcium. That would be silly.

No one has argued that, you’re beating up a straw man. You’re the only person here who argued that people would be eating a virtual kiloton of carrots each day.

But that thinking exclusively in terms of active ingredients and daily requirements leads one into that kind of thinking.

If I recall, you brought up daily requirements as an argument against both golden rice and the carrots I mentioned. You were suggesting that following the daily requirements would mean that people would have to eat tons and tons of carrots or golden rice. Now, your suggesting that paying attention to daily requirements is a bad thing.

Can you tell me where I said that we should be paying attention to mere known nutrients and daily requirements alone? Diet diversity is very important, if simply for the fact that we do not know everything we need to be healthy.

I don’t think some child in Mali cares much about GM Lycopene enriched tomatoes.

You are well prepared to talk about organic “enriching” tomatoes with flavonoids. (At the risk of repeating myself, I find this possibility to be promising and I’m not denigrating it.) Or maize enriched with beta-carotene when it is through conventional breeding. I’m only suggesting that the argumentation be consistent – which is it: “active ingredients” are to be paid attention to or ignored? I do not want to be impolite on your blog but I really do want to press you about this inconsistency.

I wanted to add that the people spending a fortune on diet pills are not being scientific at all. The benefits are not demonstrated, and in some cases argue strongly against buying such pills. The problem is that the nutritional fads in this country are outpacing the science.

Finally, I’ll tell you who needs ‘em. That kid in Mali. That kid whom “Golden Maize” may be better for than golden rice because corn is already a big part of their diet in Africa, but (s)he is not getting enough carotenoids. More than just that kid – Everyone in this world who is not able to get what they need to be healthy, whether from flaws in their traditional diets, or from their socio-economic status. They need more than active ingredients, but they still need them.

I just did an interview with someone who worked on Golden Maize, to be posted on my site Tuesday.

But then what about people who have a more than adequate diet, in fully developed countries? They’re the ones spending a fortune on vitamin pills, and all that stuff. They’re the ones who are eating and drinking foods touted for their active ingredients. I don’t think some child in Mali cares much about GM Lycopene enriched tomatoes.

My main point is not that one should depend on carrots to give one an entire daily requirement of calcium. That would be silly. But that thinking exclusively in terms of active ingredients and daily requirements leads one into that kind of thinking. I wasn’t the one who started the point about what percentage of the RDA for calcium this GM variety supplies!

I can’t prove it, of course, but it is my contention that if one focusses on a diversity of foods, the likelihood of lacking any single important nutrient is nil.

Yes, you can get carotenemia from consuming too much carotene – but as I said about the unrealistic expectation that the carrot provide all your daily requirements or it isn’t significant, getting carotenemia from eating these carrots is also unrealistic.

errr, I mean “Particularly as just last week you titled your post…”

Good post, I wanted to address a few of your criticisms. First of all, the transgenic carrots are not seen as a solution to everyone’s calcium woes – that is the same issue we had with the golden rice discussion earlier. In that discussion, you said:

Even the new improved version does not contain very much in the way of vitamin A precursors; you would have to eat an awful lot of it each day — probably an amount impossible to ingest in a day — to overcome the levels of malnutrition seen among the poorest children.

As the golden rice issue demonstrates, the criticism us unfair. Golden rice was asked to fulfill all the daily requirements of the malnourished people it is intended for. But there are other sources of Vitamin A in their diet, just not enough, and the rice would more than make up the remaining need for the nutrient.

The same sort of criticism is being made here of the transgenic carrot – that the entire daily requirement of calcium must come from these carrots, or the carrot is no good. The study’s authors have stated in many places that this is a beta-test of their hypothesis, a proof-of-concept that will lead to similar and better advancements in nutritional enhancement. Imagine, for example, if that same 41% difference in absorption of calcium can be achieved in a vegetable that already gives us a significant amount of calcium? What if many vegetables that give us some calcium can be modified in the same way, leading to a significant overall increase in calcium absorption?

As I walk down the hall in my lab building, I can find several examples of nutritional emphasis in different species – one involving calcium enhancement of potatoes.

One point I wanted to emphasize over everything else with the calcium carrot example is that they didn’t just make a carrot that they thought would give us more calcium – they did a nutritional study that showed that the participants absorbed more calcium. Contrast that to the [promising] information about tomato flavonoids, which to my knowledge haven’t been similarly studied in actual nutritional effects.

Yes, you can get carotenemia

It is true that nutritional fads outpace the science that backs them up, and people develop unhealthy obsessions with drastically changing their diet to suit some perceived nutritional benefit. Walk into a mainstream supermarket and see the products touting their trans-fat free and omega-3 rich snack foods, or walk into a Whole Foods and see their store advertisements for untested nutritional supplements, and scores of flax-infested products or snake fish-oil pills and you’ll see it even more-so.

The Pollan-esque rejection of nutrition science (and referring to nutrients at all), however, is unwarranted. Particularly as just yesterday you titled your post about tomato flavonoids “Why Organic Tomatoes are good for you.” Of course, you didn’t claim that they were necessarily better for you, but to be consistent, I don’t think you can emphasize or de-emphasize nutrients when it convenes you. Michael Pollan makes the same error, and I’ll be talking to him about that when I interview him for my show later in March (or April, schedule depending).

People take individual nutrients too far, but the response that we should almost completely ignore them goes too far in the other direction. Skepticism about food fads and the limits of current scientific understanding is a healthy attitude, one that we should all try to er, cultivate in people who well, eat.

I’m flying out to a conference later today, so I may not be able to check on responses right away. But I also wanted to let you know that I’m writing a response to your earlier question about social attitudes toward genetically engineered foods:

I agree; we’ve blogged often about varietal differences in nutrient levels, not just in rice but in many other crops. Indeed, many people know that red and black rice varieties are good for anemia. I think you are right in your implication that the reason people don’t object to high iron varieties is precisely because they were not genetically engineered. And again, I ask, why not go with the flow, even though you know it is “wrong”?