Phytochemicals in produce seem to be ignored by the experts.

Factual Questions
21

The problem with “narrow[ing] down the characteristic substance” is that all foods have a variety of substances which interact in different ways with the human metabolism. As others have pointed out, this may vary due to interactions with other chemicals, rate of absorbtion and breakdown during digestion, and methods of preparation–cooking, for instance, which we do to make many foods more palatable or digestable, destroys many naturally occuring nutrients and creates substances that can be carcenogenic or otherwise detrimental. Antioxidants, for instance, have been touted for their benefits over the last few years, despite the fact that most don’t survive digestion and have a questionable impact on health. While it’s true that an antioxidant will, under lab conditions, combine with a free radical and thus prevent it from attacking proteins in the body, in an actual metabolic environment there are so many interactions occuring that it’s hard to tell exactly what effect any individual compound is going to have. In excess quantities antioxidants can actually create free radicals, as can the monounsaturated fats that everyone is so hip-happy about. (Check out the rapeseed oil debacle in Spain the early 'Eighties and you’ll never look at a bottle of Canola oil the same way again.)

It’s useful to bear in mind that, for the most part (baring co-evolved and domesticated species) these “foods” aren’t evolved to offer nutrition but develop these substances for their own purposes (to act as natural pesticides, or aid in some stage of development, or attract pollen carriers, or whatnot) and are nutritionally beneficial or not to humans in a purely random fashion. Not everything you can put in your mouth is good for you even if it is “all-natural”.

Nutritional studies are epidemological experiements that transpire over long time periods (often years or even decades) with understandibly loose controls; often, the study parameters are created retroactively and the data filtered to match the parameters rather than created beforehand; after all, you’re hardly going to dictate to a large group of people what foods they can eat, how much, and how it can be prepared over the next 20 years. As a result, study results (which are often presented as factual conclusions in the popular media) are inferrential indicators, not hard and fast conclusions.

As others have indicated, phytochemicals comprise a vast array of different compounds, some of which may be beneficial, others may be harmful, most probably offering no significant interaction at all. Promoting “phytochemicals” as being good for you is like condemning all steroids as being bad just because a small subset of metabolic steroids (when taken in excessive quantities) can have negative consequences. I daresay, given our still limited understanding of the causes of these afflictions, that no one has yet “proven anti-cancer and anti-heart disease effects” of any phytochemical compounds. There may be correlative links, or even suggested causivity, but “proof” of such claims is a dubious claim at best, and while they might offer some small margin of benefit against heart disease or cancer, the big factors, such as general nutrition (avoiding saturated fats and getting your grains and vitamins), unhealthy behaviors (smoking, excessive drinking, exposure to toxic compounds), and genetics (nothing you can really do there), are going to predominate. If you are genetically prone to, say, breast cancer, you certainly want to avoid other behaviors which are correlated with cancer, but the odds that you’ll get cancer are largely controlled by your genes, regardless of how many antioxidant supplements you gulp down.

As tremorviolet suggests, the best thing to do, if you’re concerned about getting these in your diet, is to eat unprocessed and uncooked (or barely cooked–steamed or lightly grilled) vegetables and fruits. Not only will you get the (unknown and highly speculative) benefits of your phytochemicals but you’ll also get plenty of good old fashioned vitamins, minerals, and fiber, which ain’t nothin’ but good for you.

Stranger

22

Stranger, excellent post! Most informative.

23

For thems as was skimming that post – a point that can never be made too many times.

24

If i can go off on free radicals and antioxidants for a minute…

People talk about free radicals like they are satan’s own molecules. In fact, they play vital roles in the health of a normal human being. One that comes to mind is in the immune system. How do you think we are able to kill pathogenic microbes? At least some of those chemicals are free-radicals.

I would suspect (my own opinion here) that the body must have sufficient antioxidants to take care of free radicals when needed and that, like many other otherwise beneficial compounds, having more than you need is not necessarily better. I would wonder if having excess antioxidants might, in fact, impede some of the beneficial functions free radicals perform…

25

These plants’ chemicals are for their benefit. Any benefit we could have from them is coincidental, I agree. Very good point.

I am beginning to see why this is an issue that will probably not be fully resolved or substantiated for/by the human race any time soon. Its one of those things that has a lot of barriers to fruition of truth. But I still think we (mankind) can gather enough info to draw some decent inferences, such as whether these chemicals have a better effect on us than if we did NOT consume them. I think that much can be determined… we’ll see.

Besides, wouldn’t it benefit someone who exercises a lot (me) and who inhales a ton of carcinogenic O2 and who deals with a ton of acidity during those sessions, to consume something that protects plants from the same things? What do you think?

26

Aren’t most of the recognized vitamins themselves phytochemicals? In that case, the reason why folks talk more about vitamins than other phytochemicals is clear: Some chemicals are known to be necessary or conducive to good health, and those are the ones we call vitamins.

27

Like has been explained, there’s no evidence to suggest that it will benefit you. Stranger confirmed my suspicion that most antioxidants don’t pass unaltered through the body, which means that by the time they reach your tissues, they’ve probably lost their antioxidant effects. And what’s with the phrase “carcinogenic O[sub]2[/sub]”?

Eating a healthy diet of plenty of fruits and vegetables will provide immense health benefits for reasons that have been clear for decades. Of course you should eat plenty of them - but why do you need to invent a false rationale for doing so?

28

100% of people with cancer have breathed air containing oxygen.

29

I don’t know where you’re reading such articles or advertisements, but there are lots of general articles and scientific publications that deal with “phytochemicals”. Garlic has been studied for its anti-blood clotting effects, for example and ginger’s been looked at for anti-nausea action. There is no monolithic denial or absence of information regarding possible or confirmed beneficial aspects of produce.

Theere is, however, considerable skepticism in the medical and scientific community when terms like “phytochemicals”, “glyconutrients” and the like are tossed around as buzzwords, amid overhyped glurge about revolutionary health benefits.

30

Oh my God! Stop breathing, everyone! It’s for your own good!

. . . we’ve learned an important lesson just now about the difference between correlation and causation . . .

31

Excellent point. Free radicals are an essential component of biochemistry, and indeed, chemistry in general. Antioxidants simply oxidize (fulfill) open radicals and prevent them from damaging cell machinery or nucleic acid.

But, as Chronos points out, people get fixated on terminology (re: vitamins vs. phytochemicals) and try to make a simplistic diachotomy; witness the “organic” foods craze, in which some people will buy anything that’s “organic” under the assumption that it must be healthy, and will avoid foods that are genetically modified under the premise that they must be dangerous. Never mind that nearly every cereal, fruit, vegetable, and meat (except for most seafoods) are, in fact, the result of centuries or millenia of genetic modification in the form of selective breeding and hybridization. Certainly “organic” foods are generally fresher than high volume produce (more a result of justifying their premium prices and having to contend with shortened shelf life) and aren’t generally as heavily processed, but off the vine the nutritional difference between an “organic” tomato and its “conventional” bretheren is minimal, with the possible exception of pesticide residues (though in this way the moniker “organic” can be misleading, as it is not equivilent to bieng pesticide free.)

And don’t even mention the coverup about the environmental contaimination by dihydrogen monoxide; it’s everywhere!

Stranger

32

I think there’s some basis for nervousness about GMO foods. I’m a great believer in the concept, personally - minus some of the shitty things Monsanto has done to create an artificial dependence on their products. But centuries of selective breeding are not equivalent to inserting fish genes in tomatoes; selective breeding is a gradual process, while recombinant genetic engineering involves making substantial changes to a plant’s genome that can radically alter its influence on the environment. Look at the GMO corn that killed monarch butterflies - that was not an expected effect of it, but such unexpected effects are absolutely assured when you’re altering a species so much. Many GMO products are not well-tested, either, so it’s in the fields that issues like that become known. It’s not analogous to faster selective breeding at all, as far as I can tell.

33

The recombinant tryptophan fiasco of the late 80’s supports this contention.
Recombinantly modified bacteria, plants, or animals are placed under unique stresses by the introduction of new genes. If they survive, it’s because they’ve altered their homeostasis to accommodate the new gene products. The exact nature of that accomodation cannot usually be predicted, and is not always beneficial to humans.

34

From Wikipedia was this lovely quote
"They are usually used to refer to compounds found in plants which are not required for normal functioning of the body but which nonetheless have a beneficial effect on health or an active role in the amelioration of disease. "

So phytochemicals refers to benificial chemicals found in plants that are not required to be able to live.
OK by that definition I can say without a doubt that they are benificial to your helth.

Let me define mortochemicals as those chemicals found in plants that are not vitamins, minerals, required for life, or phytochemicals.
By this definiton mortochemicals are not benificial to your health.

Plants contain both phytochemicals and mortochemicals in varyiang degrees, food processing is believed to greatly reduce the amounts of phytochemicals and mortochemicals in a product.

I would like to know if the benifits of pjytochemicals outweigh the detriment of mortochemicals within certain plant based food stuffs.

35

Good point about Monsanto’s cupidity and price-gouging, though in fairness, Monsanto never made a secret of their marketing strategy.

On the issue of inserting genes, though: genes are genes. A gene found in, say, a carp, that makes a particular enzyme may equally be found in an apple or a wasp. By crossbreeding two different varietals of grains or hybrizing two different species of pulses you are transferring new genes, and in ways that may not be entirely predictable. The breeding and hybridization that turned the common ancestor of modern corn and maize into a readily digestible cereal also made it susceptible to rust and other fungi to which it should have a natural resistance. Similarly, the domestication and husbandry of cattle and pigs has led to the transference of numerous diseases, including (probably) smallpox and syphilis. The problem of displacing indigenous species and homogenation of domesticated food crops is one that extends back thousands of years.

If anything, GMOs are better controlled insofar as we at least know what genes have been spliced in and what enzymes and proteins they code in their native host. While this doesn’t allow us to predict with certainty what products and byproducts they’ll create in their spliced location, we can at least guestimate the effect they’ll have, whereas random crossbreeding can have all kinds of detrimental effects. (I can’t come up with a cite pertaining to cereals offhand, but looking at domestic dogs and cats we can see the various genetic and congenital disorders that have occurred due to incautious breeding.)

The problems we’re seeing with GMOs is two-fold; they aren’t allowed to develop and intermingle in the way natural selection would develop an organism, and they’re deliberately cultivated in high density, homogenous conditions which artificially protect and enhance them. A new strain that occurred naturally with properties detrimental to a symbiote would expand via normal generational rates and most likely come to some kind of new quasiequilibrium; that is, the symbiote would evolve a protection, or develop into a new niche, or would die off and make room for an adjacent, better protected species to take over the functions it filled. But domesticated species are grown en masse and with as much homogeneity as possible, in order to maximize the particular qualities (taste, nutrition, crop density, pest resistance) that the farmer desires and can overwhelm the natural progression of the evolutionary game. The homogeneity also makes them less resistant, as an overall population, to new predators and variations in conditions.

In short, the same conditions that would seem to make GMOs “dangerous” also make alien or migrated species detrimental. OTOH, GMOs offer the prospect of enhanced nutrition (golden rice), greater crop density and better land usage, greater resistance to spoilage, et cetera. For the most part, the “frankenfood” additions offer a way to better control and suit foods to our biochemistry over traditional crossbreeding. I’m somewhat more dubious about plans to splice antibiotic functions into the food chain; as with meteorology, we understand the fundamentals but are unable to predict all but the grossest effects of alterations in evolutionary developments, and bacteria evolve very quickly.

I guess (to wrap up this long-winded diatribe) my problem is that genetically modified organisms are being held up as some kind of boogie monster, a vial of biochemical nitroglycerine that, if accidentally shaken, might explode and wipe out all life on the planet, which is about a bunch of apocalyptic pseudoscientific nonsense as you can find, whereas “organic” is being touted as some kind of health miracle, no matter what kind of food product it is representing. I was at the Wild Oats this morning and walked down the snacks aisle, reveling in the enormous selection of potato chips, all prominently displaying the label “Organic!” or “Organically Grown!” (and “cooked in organic peanut oil!”) They’re potato chips, for crissake! Organic or not, they’re grease-soaked, calorie-laden nutritional voids, delicious as they may be. But most people have absolutely no grounding in biochemistry or biology (nor is a detailed survey of those topics within the conceptual curiosity of most consumers), and so they fall prey to the simplistic and oft-wrong judgment of organic:good/GMO:bad.

Don’t even get me started on Chakra Lady next to the freezer section who offers to “analyze my auras” and “realign my chi field”. I swear, if Vons would just get some better produce and hire away some of those cute hipster cashiers, I’d avoid the Whole Paycheck Foods entirely.

Stranger

36

Which is why you should always use protection unless you and the cow or pig are in a monogamous relationship and have been tested.

And of course I agree - I think GMO food is both inevitable and something that potentially offers us enormous benefits. The kneejerk naturalists are inevitably people who don’t understand anything about the actual processes that carry food (and other consumer goods) to our tables, or they wouldn’t imagine applying the term “natural” to the foods they’re eating, organic or not.

Organic has other consequences too - now the ecologically aware have to choose between organic agriculture, which relies heavily on tilling the soil to control weeds, and no-till agriculture, which uses particularly heavy coats of pesticide. One sprays artificial chemicals into the environment, while the other worses erosion, which is rapidly destroying productive farmland everywhere in the world. If erosion continues unchecked, it’s hard to imagine where our food will come from at all in fifty or a hundred years.

This is a similar variety of pathological thinking to what hauss displayed in the thread that inspired this. It’s ignoring the rhino charging at you to swat a mosquito - what sense does it make to preoccupy yourself with the tiniest, least important contributors to your health while ignoring the most important? It demonstrates pretty clearly the inability of humans to understand and evaluate risks - we ignore the important matters, we just mentally write them off - and focus on things like terrorist attacks or secondhand cigarette smoke.

37

BTW, I meant to thank you for again writing such an interesting, informative post. You are a wealth of information on this (and other things as well.) I really appreciate hearing from you.

38

I often point this out to the organic/environmentalist crowd, and it’s not just erosion but water table depletion, which is potentially an even more insidious issue, which potentially threatens to limit food production. Many genetically modified cereals are able to better tolerate brief periods of high pesticides (resulting in less cummulative runoff) or grow in untilled or marginally-tilled soil, reducing erosion.

For the most part, “natural species” ain’t. The long-term goal of agriculture should be to limit, in whatever way possible, contamination and further depletion of indigenous species and environmental conditions. The problem is we don’t always know what the effects are going to be; I recall marine aquaculture as being the up-and-coming save-yer-butts technology in the 'Seventies and 'Eighties, but now that we realize how depleted and contaminated the oceans are becoming, and how drastic runoff effects are on marine habitats it’s kind of fallen by the wayside.

Hopefully Charleton Heston won’t be running around divulging the secret ingredient of McDonald’s new 'McSpam Burger" any time soon, but we do need to be more aware of the effect of agriculture, particularly of intensive “ranching”, lest we end up shatting in our own larder.

Yeah, I loved the “I want scientific evidence to back up my purely unfounded notions of health” mentality, especially when he tells an MD off for being ignorant. :rolleyes:

But, back to the OP (somewhere back there…oh, there it is) the reason “the experts” don’t talk about phytochemicals as a class is because, in a nutritional sense, they don’t function as a class. Bippy’s definition aside, most compounds identified as phytochemicals have either speculative or no known causative benefit when digested. Most of the matter you put through your body doesn’t get used nutritionally, or at least not directly. (Most fiber and water isn’t “digested” for food but rather serves to clean and act as a medium for waste.)

Hey, look in the bright side; at least they haven’t distilled nutrition down to a single product. Just imagine: [announcer voice] “McCola-Swanson’s New Improved All-Complete Protein Paste! Complete nutrition in half litre, litre, and the family-sized 3 liter tube! Now in four new colors, but the same great vaguely discernable taste!”[/av]

Stranger

39

Excalibre? Stranger On A Train?

Well done, you two! Keep fighting the good fight!

40

Which means more fishing of the depleted wild fisheries . . . it’s a major problem either way. But aquaculture - at least as it’s practiced; I’m not sure if there are better methods people have come up with - is a terrible polluter of the oceans, and it pollutes the gene pools of wild fish when farmed fish (bred, of course, for size, not survival potential) interbreed with them. That’s a nice illustration, actually, of the point you made about the perils of breeding species to be more convenient.

This is the major reason that I’m a vegetarian, actually - animal farming practices are disgustingly destructive to the environment. The land loses productive value, huge manure lagoons are required - it’s a horror. I try to eat a little lower on the food chain to minimize my contribution to the problems of modern agriculture.

Is there a word for the type of thought process behind this? It seems to be endemic to pseudoscience: whether you’re talking about “energy fields” or “toxins” or “phytochemicals”, you’re lumping a hundred different things together and imagining them to have nebulous, indefinable good or evil qualities. The scary thing is that this kind of thought process underlies many people’s behavior.