When it comes to healthy eating, humans have a lot to learn, or relearn, from wild and domesticated farm animals.
This “nutritional wisdom” has been a career-long research focus for University of Utah professor emeritus Fred Provenza. It was also a focus during three sessions he delivered at the recent sixth annual education conference of the Ecological Farmers Association of Ontario (EFAO).
Originally from Colorado, Provenza earned an undergraduate degree in wildlife biology while also working on a ranch in his home state, before moving north to further his research into animal behaviour. Previous books have explored wildlife foraging and shepherding, but he gained prominence in human nutritional circles with the publication in 2018 of “Nourishment: What Animals Can Teach Us About Rediscovering Our Nutritional Wisdom.”
Why it matters: The easy access to highly processed food, both for farm animals and humans could have decreased our ability to find the food we need.
Nobody has to tell wild animals what to eat, how much, or how to self-medicate by altering their diet to include rarely eaten foods. Why?
“Because they’re still in an environment,” Provenza suggested. “They’ve been successful. They know how to do that.”
Even laboratory rats, through a study offering diabetic rats a range of foods that may or may not improve their condition, have been shown to instinctually self-medicate. Yet many modern livestock animals, and humans, appear to lack these instincts.
“Do we lack the ability?” Provenza asked. “Or has that been hijacked? I would argue it has been hijacked.”
Citing the book “The Dorito Effect” by Canadian Mark Schatzker, he suggested the “phytochemical richness” of commercially available fruits and vegetables has declined over the past 50 years. For this, he blamed the widespread practices of delivering nutrients through irrigation, of restricting livestock indoors, a regimen of prepared feeds, and picking and shipping produce while it is still green.
Provenza’s earliest studies about how animals choose what to eat involved wildlife. “The mother links the offspring to the ancestors and the landscape,” he explained, adding that the taste system in a human fetus is fully functional in the last trimester of pregnancy. After birth in mammals, the tastes get transferred in the mother’s milk. And when the mother starts foraging, the offspring follow.
If a unique environmental condition occurs early in an animal’s life, and the mother selects a rarely eaten food to fend off disease or starvation, the offspring will return to that food years later if presented with that same environmental condition.
It wasn’t long, though, before it occurred to Provenza that domesticated livestock might share these abilities clearly exhibited in wildlife. He showed a video from a trial he ran with lambs that were mildly deficient in some nutrients. Straw isn’t a food lambs are particularly attracted to, though they would eat it more if it was flavoured with maple or apple. But when he drenched some of the straw with the nutrients the lambs were lacking, the video showed one group of lambs enthusiastically eating, while another group in the next paddock sniffed the same straw without nutrients, and walked away.
He has since researched energy in feeds, energy/protein ratios, minerals, vitamins, and many “secondary compounds” such as phenolics, alkaloids and various nutrients — what he describes as “a lot of work that showed that (farm) animals can self-medicate.” In particular, he said, it has been clearly shown that when you supplement one type of nutrient or compound in the livestock barn, it changes the selection by the animals when they go out to pasture.
Then, in researching and writing “Nourishment,” Provenza again broadened his exploration of nutritional wisdom — to include humans.
“There’s not a huge amount of literature on the topic.” But there is evidence from the historical and anthropological records that self-medicating does happen. Examples include the use of cod liver oil to prevent rickets, craving for salt, and the craving for fruits and vegetables to prevent scurvy.
The lamb study with straw, he suggested, could be likened to humans eating processed foods. It’s a relatively poor nutritional choice, but food manufacturers have come to recognize that positive feedback can be created by injecting a blast of flavour and/or energy in a processed food.
“And then you target kids with your marketing,” he said, adding this leads to early adoption of unhealthy eating.
What’s instead needed for our society to return to healthy eating, Provenza argues, is for the system of food production to return to practices that promote richness of flavour and density of nutrients. Nutritional science, meanwhile, should move away from analyzing the effects of singular compounds on the so-called “average” person, and instead recognize that each person’s body reacts uniquely to the combination of nutrients, minerals, and other compounds contained within their diet.