Paleo is rooted in the science of evolutionary biology, which posits that organisms are finely tuned organic machines that have evolved to eat very specific diets. Little diet changes can have massive, life altering effects. Zoology gives us a window through which we can view the life-threatening ramifications of mismatched diet habits.
Lessons From Zoology
The Carnivorous Cat Debacle
Zookeepers and veterinarians at renowned facilities, like San Diego Zoo, realized long ago that they need to mimic each wild animal’s natural environment as closely as possible. These experts have begun to recognize that it’s also crucial that they replicate each species’ natural diet, if they want their animals to stay healthy and reproduce in captivity.
In his book, Paleo for Ahtletes, the father of the Paleo diet, Dr. Loren Cordain, explains how slight alterations in an organism’s natural diet can have life-threatening consequences: “In the past, when lions or any other purely carnivorous cats were fed only raw muscle meat, their health rapidly deteriorated; they developed vitamin A deficiency, bone loss, and eventually died” (Cordain, 145).
These health issues initially stumped zoologist. Observation of wild lions eventually provided the answer. Wild big cats eat more than just muscle meat. They eat entire carcasses- including organs (like the liver, which is an excellent source of vitamin A) and bones (like the calcium-rich ribs). “Accordingly, both vitamin A deficiency and osteoporosis were averted when these wild animals ate the diet that they were genetically adapted to eat…..Pure carnivores like cats are literally genetically programmed to eat the flesh of other animals” (Cordain, 145). Even a small deviation from a big cat’s natural diet has devastating ramifications. The effects of diet changes observed in animals like big cats is now helping to unlock health mysteries in gorillas and humans.
The Captive Primate Predicament
Heart disease, which is rarely observed in wild gorillas, is one of the leading causes of death among captive gorillas. Nearly 70% of captive gorillas in the U.S. die prematurely as a result of this disease. Why does heart disease afflict only captive primates? Zoologists and veterinarians from Case Western University and Cleveland Metroparks Zoo believe the answer may be diet.
It’s common for zoos to feed captive gorillas and monkeys high starch, high sugar biscuits as a major part of their daily diet. These biscuits were designed to include the vitamins and nutrients present in a wild gorilla’s diet. Now, research is showing that these high glycemic, processed biscuits, which are not a natural source of vitamins and nutrients, are contributing to the heart disease observed in captive gorillas.
In Paleo for Athletes, Dr. Cordain discusses the ramifications of this diet change: “When new and different foods are fed to animals, it almost invariably results in ill health or disease. Zookeepers know that exotic species of South American monkeys can be kept alive on cereal-based chow, but these animals don’t do well, are prone to disease, and will not reproduce under these conditions. Only when they are fed their normal diet of insects, leaves, and tropical fruit do they thrive and produce offspring in captivity” (Cordain, 145).
To test their theory, the researchers at Chicago Metroparks Zoo decided to remove the starchy biscuits from the diet of their captive gorillas and instead replace them with dozens of pounds of vegetables, which are the natural source of vitamins and nutrients in a wild gorilla’s diet. Within the first year of the diet change, the gorillas each lost 60 pounds and the researchers saw fascinating behavioral changes; the gorillas stopped regurgitating their food and they ceased plucking out their own hair (both behaviors are frequently observed in captive gorillas who eat a high-starch, biscuit-based diet, but are never witnessed in the wild).
Now, years after the initial diet change, researchers have discovered something even more fascinating: the gut microbiomes of gorillas with heart disease, who are eating a diet full of the starchy biscuits, resemble the microbiomes of humans with diabetes. Conversely, healthy gorillas who are subsisting on the high fiber, low-starch, unprocessed diets reflective of their wild counterparts’, have gut microbiomes similar to that of healthy, diabetes-free humans.
How This Research Applies to Humans
What does all this new research mean? It underscores how sensitive organisms are to diet changes. Animals, including humans, are finely tuned organic machines. Slight variations in diet, can have a cascade of harmful effects. Even though the biscuits that were being provided to captive gorillas were full of vitamins and nutrients, they contributed to the primates’ heart disease. Gorillas in the wild obtain their nutrients from whole, unprocessed, low glycemic sources. Changing their food source from unprocessed, high fiber vegetables to starchy biscuits, can induce a life threatening disease, even though the nutrient profile between biscuits and vegetables may be similar.
This research has implications for human nutrition. It suggests that high glycemic, starchy diets may be linked to both heart disease and diabetes in people. If gorillas and other animals suffer when feed processed foods, it’s likely humans do too. The importance of choosing the source of our nutrients is underappreciated. Although cheerios and other processed foods may contain added vitamins and nutrients, they are not the best choice. We should be getting our vitamins and nutrients from unprocessed, and natural food. Source matters significantly.
As the above research shows, subtle changes in the diet of animals has been shown to have drastic results. What’s most frightening is that our species has deviated further from our natural diet than zoo animals have. Thanks to modern technology, we’ve recently been able to process foods in ways never before imagined; it may be many years before we’re able to fully witness the catastrophic health effects induced by these huge changes.
From Pantry to Refridgerator
What’s the solution? We need to eat a diet similar to the one our species subsisted and evolved on thousands of years ago, before modern agricultural and processing methods developed. This means focusing on a diet comprised of whole, unprocessed, natural sources of meats and vegetables. A high fiber, low glycemic diet, similar to our PaleoFTMC approach to nutrition, may be the best preventative medicine to protect us against the mismatch diseases plaguing our Western culture.
Additional Food for Thought
The researchers in Cleveland also believe that exercise plays an important role in the health of gorillas. Wild gorillas spend hours a day foraging for the dozens of pounds of produce they need to survive. Captive gorillas do not- until now. Researchers are experimenting with creative ways to make captive gorillas forage for their food within the confines of their enclosures.