and preserving foods (Krebs 2013). The shift from hunter‐gatherer of wild foods to consumption of agricultural produce allowed the human population to increase and for greater socialization to occur (as foraging for food in hunter‐gatherer societies can take on average nearly seven hours of the waking day) (Soukand 2016), but the net effect on human health initially was negative. Early farmers suffered stunting (a form of malnutrition) and higher tooth decay than wild foragers, likely due to the less varied diet higher in farmed grains (carbohydrates), but as agriculture became better established and more efficient, it provided a more reliable and stable, easily stored food supply for humans (Krebs 2013). However, agriculture’s emergence has dramatically changed the nutritive and phytoactive content of plant foods.
There are relatively few direct, side by side published compositional (or efficacy) comparisons of wild versus cultivated plants, in part because the genotypes of cultivated plants have for the most part been selected and bred for adaptation to a large‐scale cropping regime, and typically diverge widely from parent genotypes endemic in wild settings. A recent study analyzed the differences in mineral composition of wild, naturally growing and cultivated blueberries (V. myrtillus versus V. corymbosum, respectively) by inductively coupled plasma optical emission spectrometry, and reported that the wild species were higher in five minerals (Ca, Na, Mg, Mn, and Zn) while cultivated plants were higher in Fe and Cd, which was related to the composition of the soil at the farm site (Drozdz et al. 2018). However, it was necessary to examine two distinct species in order to compare wild to cultivated blueberries. Another recent study compared mineral composition of wild and cultivated blueberries and cranberries, but had to rely on comparisons of fruits and leaves of two different blueberry species (V. myrtillus and V. corymbosum) and two different cranberry species (V. oxycoccos and V. macrocarpon) to determine their statistically distinct micronutrient compositions in wild versus cultivated, respectively (Karlsons et al. 2018). Wild genotypes of Vaccinium species in general demonstrated higher health‐relevant bioactive potencies than cultivated selections in other studies (Braga et al. 2013). A wild banana species had higher phenolic and tannin content, and higher antioxidant capacities measured in three distinct assays than a commercial banana variety (Sasipriya et al. 2014), and wild strawberries recorded antioxidant capacity three times higher than cultivated strawberry genotypes (Ozgen et al. 2007). With few exceptions, studies have reported higher phytochemical content and bioactive potency for wild genotypes as compared to cultivated fruit selections, but in nearly all cases the species or genotypes collected in the wild were different than those produced under cultivation (Li et al. 2016).
3.4 Animal Mimickry/Zoopharmacognosy
An evolutionary relationship between plants and mammals has conditioned the unique physiological/biomedical effects of wild plants (Wynn and Fougere 2007). Traditional ecological knowledge (as held in indigenous tribal communities) asserts that at least some animals instinctively know how to treat their own injuries or ills and self‐medicate using herbs growing in the wild. Consequently, traditional herbalists routinely use judicious observations of the behavior of sick or distressed wild animals to locate new potential human remedies derived from wild plants (Engel 2007; Wynn and Fougere 2007). Native Americans, as well as tribal groups throughout the world, have observed animal feeding behavior and used these clues to guide their own use of polyphenol‐rich plants as medicines for specific ailments. For animals, is it assumed that nutritional wisdom or use of plant resources for healing is a combination of post‐ingestive hedonic feedback and individual learning. Animals can use hedonic feedback to find ways of removing the unpleasant sensations of disease and injury. Some research has asserted that there is a purgative effect on the animal’s intestines that helps alleviate parasitic infections (see details below), whereas other theories maintain that the natural antimicrobial/wound‐healing effects provided by plant polyphenols are impetus for a wild animal’s tendency to seek berries or other polyphenolic resources, especially after they’ve incurred defensive wounds.
Zoopharmacognosy is defined as the use of plant medicines/medicinally active herbs by animals—specifically when an animal seeks out a plant that is not normally part of its diet (and may have no nutritive value) in order to cure injury or disease (Moerman 1996). Mammals and even birds and insects are able to self‐medicate using plant resources for both physical and psychological treatments. Native Americans revered the bear as one of the most advanced animals in terms of self‐medication, as they use their clawed paws to dig for medicinal root crops (Densmore 1974).
Native American traditional ecological knowledge observed that animals tend to “self‐regulate” tannin content via the diet (Moerman 1996; Engel 2007). Feeding deterrents (like tannins) are deliberately sought out by animals when the bioactive benefits outweigh the adverse tastes. For example, wild deer deliberately select plants not with very low tannin content, but those with moderate tannin content, as an adaptive taste preference, presumably because of the impact of the tannins on intestinal parasites. Repeated evidence suggests that animals attempt to self‐regulate tannin consumption to optimal levels. Similarly, the Asiatic two‐horned rhinoceros periodically will consume copious amounts of mangrove bark (tannin‐rich) to the point where their urine turns orange, to self‐medicate against endemic dysentery, just as a common medication for human dysentery (clioquinol) has a 50% tannin content (Engel 2007). During the coevolution of plants and animals, animals developed receptors for plant‐produced bioactive chemicals (benzodiazepine, opioid, and vanilloid), which had direct effects on the sensations of pain or of consciousness; the animal‐to‐plant relationships provided a template by which herbalists could treat human patients for seizures, anxiety, and pain.
Natural selection has streamlined a variety of animal behavioral health maintenance strategies. These innate behavioral strategies are well documented for wild animals and although the capacity is partially lost in domesticated animals, the latter have also been observed to self‐medicate. It has been noted that Native Americans who depended on their domesticated animals and observed their behaviors (e.g. Plains tribes and horses) had greater knowledge of plant medicine than other tribes (Stowe 1976). Farmers in New Zealand have noted that when captive deer grazed on forage containing tannin‐rich plants such as chicory, there was significantly less need to administer chemical de‐wormer. Parasitized deer and lambs selectively choose bitter and astringent chicory, which reduces their parasite loads. Consumption of condensed tannins increases sheep lactation, wool growth, and live weight gain by reducing the burden of internal parasites (Wynn and Fougere 2007).
Enthusiastic consumption of other polyphenol‐rich plants, including wild berries, is a typical behavior for dogs (Sueda et al. 2008). Anecdotal evidence suggests that dogs will mimic humans when foraging for berries and harvesting from gardens. Dogs apparently love all types of berries—blueberries, strawberries, blackberries, and raspberries have all been scavenged, often to the chagrin of their owners, as well as peas, fallen apples, and corn on the cob from gardens. Sled dogs routinely accompany their owners during wild berry harvesting in Alaska, as a safeguard to keep foraging bears at bay, and these dogs routinely scavenge the berries from the lower branches in a berry stand. In a formal study on the antioxidant status of sled dogs fed wild blueberries, berries were initially mixed into the kibble and fed to the treated animals; however, it soon became apparent that the dogs preferred the berries and if placed on top of the kibble, they’d eat the berries first (Dunlap et al. 2006).
While it has been suggested that domesticated dogs are more omnivorous than wild animals, scat analysis has shown that wolves consume plants as well (Engel 2007) (Figure 3.1). As facultative carnivores, dogs and wolves do not have a physiological requirement for plant carbohydrates, but plants in the canine diet can play a role in health maintenance. Fruits are a vitamin and mineral source for the animals as well as a fiber source. While canines lack salivary amylase (to break down plant carbohydrates) they do produce the enzyme through the pancreas and small intestine. Scat analysis and anecdotal observations of hunters and trappers indicate that fox, coyote, moose, and wolf typically have plant fiber hulls and berry seeds/skins
