 By Benjamin V. Treadwell, Ph.D.
‘Tis the season of giving and plants have always been very generous to humans. Beyond materials we use for clothing, shelter and heat, they’ve provided a source of food all animals ultimately require to survive. Not to mention virtually all the essential nutrients we call vitamins.
 Perhaps more important, but less appreciated, is the plant world’s gift of numerous medicinal compounds (like aspirin, originally extracted from willow bark) that have improved our quality of life dramatically. In fact, of the current, most popular drugs produced by pharmaceutical companies, a significant percentage is extracted from plants.
These observations might lead an inquisitive mind to wonder why our cells respond to plant compounds and how we came to rely on what plants provide.
Dependent by Design
The Christmas tree many of us display at this time of year could have more meaning than you imagine. It may be a distant relative. Seriously, it’s probable that both the animal and plant kingdoms are descended from a common ancient ancestor. This primitive life form consisted of a network of biochemical reactions, the precursors of the more sophisticated metabolic pathways present in today’s higher life forms.
One theory holds that the capacity to produce some of the compounds involved in regulating the ancient metabolic pathways was retained by plants during evolution. Animals, on the other hand, may have lost the ability to manufacture the early controls, but still retained the capacity to respond to them. Vitamin C is just one example of this type of compound.
Divergent evolution could explain, to some extent, the animal kingdom’s dependence on plants for life-sustaining constituent nutrients. Their production requires cellular “machinery” and energy. Perhaps obtaining them from plants, was simply more efficient for the animal cell. In any case, it now appears there are newly discovered plant-derived nutrients to add to the list of what we need from our distant relatives.
Pockets Full of Vitamins
Extensive studies by biochemists during the past century have demonstrated how most vitamins function in our bodies at the molecular level. Specifically, research has shown that many of the vitamin-dependent cellular machines, the enzymes, contain specially developed pockets where a vitamin lodges to carry out its function. These pockets are only able to keep us healthy if there is sufficient diet- or supplement-supplied vitamin in the body to fill them.
 Current research is discovering additional plant-derived nutrients – the grape-derived phenolic resveratrol, turmeric-derived curcumin, onion/apple-derived quercetin, green tea-derived catechins, broccoli-derived sulforaphane and strawberry-derived fisetin, among others – that act on specific metabolic pathways, eliciting surprising cellular health effects. Unlike vitamins, these nutrients have not yet been linked to designer pockets in enzymes.
New Nutrient Interactions
Also unlike the vitamins we are familiar with, these newly discovered nutrients may not be as critical to our immediate health. In other words, we may be able to remain reasonably healthy without them for long periods of time. However, like vitamins, our cells can’t manufacture them and our metabolic pathways may function more efficiently in their presence.
Furthermore, although designer-pockets have not yet been discovered for these nutrients, they do interact with specific sites on key regulatory cellular molecules. This interaction is believed to elicit biological effects. Primarily demonstrated in animal and cell culture studies so far, some of them are impressive like an inhibition of cancer growth, improved energy production, removal of age-associated deposits in the brain linked to memory decline, protection of the nervous system, increase in bone density and decreases in inflammation and the biological markers of aging.
Staying Connected
This story of the benefits of various compounds in plants is evolving at a fast pace. In the past few years, close to 3,000 articles have been published on resveratrol alone. The results of these studies are fascinating as they provide more information supporting a still viable metabolic connection to our distant plant relatives.
In one sense, we have evolved into a complex network of biochemical pathways allowing for the development of a potent central nervous system that distinguishes us from other forms of life. However, we remain inextricably tied to plants, in that the pathways we once shared require many compounds only manufactured by them but still essential to our health.
Although this story is far from complete, it does present a strong case for including a variety of plant-derived foods in our diet for maximum well-being…and happier holidays. |
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In a recent essay, published in a May, 2008 issue of Cell, Konrad Horwitz and David Sinclair discuss potential reasons that plants, and their various constituent nutrients, promote the health of the animal kingdom.
The well-known resveratrol researchers note that, although many plant molecules are considered “dirty” because they interact with multiple human enzymes and receptors, dozens of these bioactives are surprisingly safe and produce wide-ranging benefits. Horwitz and Sinclair offer multiple examples, from salicylic acid (SA), or aspirin, which the Greek physician Hippocrates wrote about in the fifth century, to more recently identified nutrients like resveratrol, green tea polyphenols and curcumin from turmeric.
By way of explanation for the ability of plant molecules to interact beneficially with animal physiology, the authors refer to a theory that both kingdoms descended from a common ancestor. Some of the components of this ancestor’s metabolic pathways were retained in both plants and animals. Plants also retained elements involved in the regulation of the pathways.
The animal kingdom lost the capacity to produce the regulators, largely due to their availability from plants and the biological advantage of no longer requiring the energy-consuming cellular machinery to synthesize them. This did, however, make the animals dependent on plants for the nutrients necessary for maximum health.
Taking the theory a step further, Horwitz and Sinclair talk about a mechanism, which may have evolved in animals, to detect specific chemicals in the plants they eat. These chemical cues, synthesized by plants for their own survival when they are under stress (infected by a pathogen or exposed to drought conditions), tend to upregulate pathways that provide stress resistance in animals and trigger beneficial reactions.
Horwitz and Sinclair coined the term xenohormesis - from xenos, Greek for stranger, and hormesis, the term for health benefits provided by mild biological stress - to explain the phenomenon.
This
Research Update column highlights articles related to recent scientific
inquiry into the process of human aging. It is not intended to promote
any specific ingredient, regimen, or use and should not be construed
as evidence of the safety, effectiveness, or intended uses of the
Juvenon product. The Juvenon label should be consulted for intended
uses and appropriate directions for use of the product.
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