One way of defining functional foods is that they are consumed for day-to-day energy balance and bodily maintenance but “may” have additional health benefits.
Functional foods are like regular foods in many ways. Just as in foods that do not advertise themselves as being nutraceutical or functional, their “Nutrition Facts” label clearly indicates a number of calories, along with quantities and percentages of given types of carbs, fats, vitamins and minerals contained, and how much of the recommended daily needs are met by consuming a suggested portion.
The difference is that while there is widespread scientific and clinical consensus on the standards for accuracy of that Nutrition Fact Label information, as well as support for the efficacy and safety of the nutrients that are mentioned on that label, there is often significantly less factual basis for much of the additional “scientific”-sounding terminology that appear elsewhere on package labeling or in advertising, that suggests those “additional health benefits.”
The most important new health claims are made in bold lettering and only partly offset by fine print warnings that these foods are “not intended or claimed to aid in the diagnosis or treatment of any specific diseases.”
Nonetheless, there is a great rise in the use of terms such as “bioactive ingredients” as if all substances tagged with this, were clearly beneficial to a significant degree for human health.
“Bioactive” simply means that the ingested materials are likely to react chemically within the body, as opposed to being relatively inert. In point of fact, the poisons in mushrooms and snake venom are also “bioactive”.
“Bioavailable” is actually a more useful term, in that it should indicate what proportion of the purported active ingredient is actually released into the body in a way the body can use. In other words, a proposed functional food, like a fish, may be potentially a good source of calcium if one eats the bones. This might be fine for sardines, but, apart from any choking it would cause, swallowing the bones of a codfish would not likely cause for much release of the calcium in a form useable by the body, because the calcium in large fish bones is not particularly “bioavailable.”
And one increasingly finds in nutraceutical and functional food marketing mention of their products having specific categories of naturally occurring compounds that share some characteristic chemical structure or have purported pharmaceutical functionality.
The technical definition, molecular formula, and 3-D drawing of these compounds would make for a good test question for courses in advanced bio-organic chemistry. But the names of these compounds are instead, tossed out to the lay public as if that knowledge was common or self-explanatory.
In reality these compounds are vaguely perceived as being “something medical and important” to most consumers. These compounds are consequently inferred by the consumer to be something essential to their very survival, or at least something of which they ought to have more of, to avoid any “unhealthy deficiency.”
The Best Case Scenario: Antioxidants
Antioxidants are any chemical compound that reduces electron loss in chemical compounds ----- indeed “reducing agent” would be an equally valid term, although not one in common usage in human nutrition.
The aim of reducing oxidation is to stabilize the structure of many biochemicals within the body, which function best in an unoxidized state, or in some cases, seriously malfunction when oxidized.
The causative agents promoting these malfunctions are generally termed “free radicals,” although in Cambridge, MA and Berkeley, CA, they are probably re-named “ bourgeois capitalistic tools, “ to avoid offending the bulk of the populace.
Antioxidants in general have the most conventional science in their favor. Indeed, it is now well established that vitamins A, C, E, beta-carotene, and the trace element selenium work at least partly through their antioxidant capabilities, and recommended minimum daily requirement have long been established.
There is indeed some evidence developing that they may work by helping to stabilize the process of DNA replication, and that some people could benefit even more from these antioxidants if an optimal match could be made between their genetic needs and the antioxidants that would best support this stability, fostering a new field of Nutrigenomics.
What is not clear is what are the specific levels of total antioxidants of all types, one must have before there are too many or too few for good health. The underlying goal is to somehow have enough of a supply of antioxidants to avoid adverse effects, without shutting necessary oxidation activities (like breathing and digestion!).
There are, unfortunately, many more claims that antioxidants “boost immunological functioning”, “cognitive ability”, and “reduce infection and inflammation” and even cure the common cold, than there is evidence that any of these assertions are true.
There is some evidence that the body is less capable of handling free radicals with increasing age, but, unlike some claims made in advertising, it is not clear that an insufficiency of dietary antioxidants causes aging (it is clear to me that living for a long time causes aging) as well as diseases of cumulative effects like some cancers, and macular degeneration.
There is a good deal of epidemiological information that people who consume diets naturally rich in antioxidants ------typically five or more servings of vegetables and fruits -----are healthier. And, at least in the case of macular degeneration, there is evidence that consuming mega-doses of certain antioxidant vitamins (specifically the Age-Related-Eye-Disease-Study or AREDS formulation) slows the progression of macular degeneration, although it is not clear that an absence of antioxidants was the cause of the disease in the first place.
There is conversely some evidence that an overabundance of some of these antioxidants (vitamins A, E and beta-carotene) can increase mortality in certain populations. Smokers with early macular degeneration are given a modified formulation of AREDS vitamins for this very reason.
What specialized categories of antioxidants seem to be making the news most often as being parts of nutraceuticals or functional foods? Lets look briefly at a few categories.
Carotenoids
Lutein, zeaxanthin, and lycopene are among the most commonly mentioned antioxidants. They are called carotenoids, quite frankly because they were first isolated in carrots, although they are widely available in many leafy green plants (but overshadowed by the green pigments). Most of these antioxidants are naturally colored with shades ranging from yellow (marigold petals are used in most AREDS formulations) to orange (carrots) to red (lycopene, for example is particularly found in products made from ripe tomatoes).
The Polyphenols, Particularly the Flavonoids
The nomenclature for the flavonoids comes in part from the Latin term for blond and indeed, a dynasty of Roman emperors, the Flavians, were all (real or bottled) blondes (and major league throwers of Christians to the lions.) .
In fact, this is another family of yellow to red colored compounds with antioxidant capabilities, although their organic chemical structure involves more carbon rings ( particularly phenolic rings) than the carotenes, and there is a branch of this chemical family that also has blue and green tints.
Like the carotenes, polyphenols are largely present in fruits and vegetables, particularly highly colored berries, grapes and citrus. But owing to that blue-green branch, they can also be found in tea and cocoa plants.
Not too surprisingly, the polyphenol antioxidant resveratrol, which is found in darkly-colored grape skins , has suggested that red wines in particular, might well function as nutraceuticals. Peanuts, it turns out, also have a significant amount of this category of antioxidant.
Isothiocyanates
Sharing a blue-green coloring with one branch of the flavonoid family are for some members the Brassica or Cruciferous family of plants. Broccoli, Brussel sprouts, cauliflower, horseradishes, kale, mustard greens, radishes, turnips, watercress and even wasabi are included, although to date, few functional foods seem based on these healthful, but frankly gassy plant foods.
Carbon Sulfides
While hydrogen sulphide, the smell of rotten eggs, is arguably the strongest stink on the planet, the organo-sulphides are another, and rather popular, class of functional food antioxidants, despite their sometimes overpowering smell. The most famous of these are various garlic-based supplements.
The Need for Standards in Making Claims of Quantity, Quality & Efficacy
There is indeed, growing evidence that nutraceuticals and functional foods that contain antioxidants that do just what they claim to do: promote human health, although the extent is quite unclear.
But there is at least as much evidence that the so-called health-food and nutritional supplement industry sometimes plays fast and loose with the levels of the antioxidant that are present, from batch to batch, or which are in fact, truly “bio-available” and in general, exercises less quality control, by far, than the convention medical/pharmaceutical industry. The paper by Griffiths et al. in the January 2009 inaugural issue of the Journal of Functional Foods , below outlines an excellent proposal for this industry to adopt the Council-of-Experts” approach used by the US Pharmacopeial Convention, Inc.
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In point of fact, the poisons in mushrooms and snake venom are also “bioactive”.
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Posted by: Living Will | January 13, 2009 at 10:09 PM
As people continue to live longer, the incidence of eye disease such as macular degeneration is on the rise. These types of debilitating eye diseases rob people of vision, and can result in individuals losing their independence.
It is believed that the visual system requires up to 25% of the nutrients we take into our bodies in order to stay healthy. Impaired circulation and/or poor absorption of nutrients can significantly contribute to eye disease.
There is a great deal of peer review research now showing the vision can be preserved through a proper diet and specific nutritional supplementation.
Essential nutrients include lutein, zeaxanthin, omega-3 fatty acids, taurine, gingko biloba, lycopene, vitamin A, E, zinc, copper, selenium for example, that can help both prevent the onset of eye disease such as macular degeneration as well as help preserve vision for those with macular degeneration.
For more information and specific research studies by eye condition on nutrition and vision, go to www.naturaleyecare.com
Posted by: Michael Edson, MS, L.Ac. | January 09, 2009 at 07:34 AM