Many diets purport to be optimally designed for the human body, and the Paleo Diet is no exception. This well-known dietary plan was popularized in Dr. Loren Cordain’s 2002 book of the same name, and is based on the hypothesis that our bodies’ dietary needs are based on our early evolution as hunter-gatherers. It states that humans are evolved to eat the foods available during the Paleolithic era, approximately 2.5 million to 10,000 years ago (before the advent of agriculture). This means an emphasis on lean meats and eggs, fruits, vegetables and nuts/seeds, and avoidance of grains, legumes, dairy, refined sugar, salt, and any highly processed foods. It can generally be thought of as a high protein/low carbohydrate diet and the increase in fiber and protein is meant to keep you full so calorie counting is not necessary. Cutting down salt, refined sugar, and highly processed foods follows most mainstream dietary advice and most sound dietary plans will suggest at least a decrease in the presence of these items in your food. But is the complete removal of grains, legumes and dairy necessary? Recent discoveries in the field of paleo-archeology and genetics potentially point to an answer: no, not really.
The Paleo Diet’s basis for cutting out these staples of modern human diets (grains, beans, and dairy) is rests on its interpretation of our genetic make-up more or less settling into its modern state around 10,000 years ago, and that chronic degenerative diseases in our population are a result of sub-optimal nutrition from this diet, most specifically the addition of refined carbohydrates. This mismatch between Paleolithic genes and modern food intake is called the “evolutionary discordance hypothesis”, which first appeared fully in a 1985 scientific article entitled “Paleolithic Nutrition: A Consideration of Its Nature and Current Implications”. But, fifteen years of scientific discovery, including the sequencing of the human genome, has presented some difficult challenges for this hypothesis to overcome.
The idea that our bodies have not significantly adapted to match our diets post-Paleolithic times (ie. 10,000 years ago) is largely becoming a difficult pill to swallow. Archeological research has shown starches and grains making a very early appearance in pre-agricultural diets well before the end of the Paleolithic era, and dairy products not long after. Furthermore, all foods available today are widely different than those available to our Paleolithic ancestors, meaning adherence to a Paleolithic lifestyle of eating is not really possible, even if one were to follow the guidelines. 10,000 years of artificial selection for bigger and more calorie dense vegetables and animals, for example, has seen to that. And quite a few genetic changes in our own bodies have arisen since this time as well. Lactose tolerance evolved independently in many localities (e.g. Europe and the Middle East) around the world over the past 7,000 years. Malaria resistance and eye and hair color variations have also evolved over that time period, and continue to evolve today. Perhaps more importantly, the billions of gut bacteria which live in our intestines and are a crucial part of our digestive system (helping break down tough plant matter, for example) evolve extremely rapidly, as our understanding of anti-biotic resistance has shown.
The diet also does not take into account the sheer scope of human being’s variability across the world. Isotopic analysis of early human remains from different global regions has shown some had more meat heavy diets, while others had more plant heavy diets. Human’s being opportunistic nature and problem-solving ability likely meant we took as much calorie dense foods as we could get our hands on, depending on what was available wherever we were. This can be seen in more modern examples as well. Some recent human diets feature far more meat than others – the Inuit people of Greenland for example – because very few edible plants grow in the environments, they live in. Diets in south and east Asia, as evidenced in Hindu and Buddhist practices, have been largely plant-based for several thousand years. The simplicity of the Paleo diet masks these differences which have always made us human. Finally, the lifestyle of paleolithic hunters-and-gatherers means that they were in fact out and about all day, moving and expanding high amounts of energy, meaning their caloric needs are going to be different than are our more modern sedentary lifestyles, regardless of genetic history. The idea of any single ideal human diet negates the depth to which we have and continue to evolve to the challenges of attaining food in nature.
What the paleo (and for that matter plant-based, Mediterranean and many other) diets do get right is a significant decrease in highly processed foods and an emphasis on leaner meats and healthy fats. This has long been shown to be a healthy, long-term dietary rule that will continue to serve as a guide star to all those wandering down any dietary path. A focus on whole foods is also a positive, and many people may find some success with the Paleo diet plan. But it is likely not the only diet humans have been, and continue to, be adapted to. For those looking to try the paleo diet, we do offer Paleo meal planning, with meals that have been carefully designed by our expert nutritionist and founder, Jackie Keller.
No ideal human diet has every existed, and diets have always been in flux due to changes in the attainability of resources both across different regions, and different time periods. What is certain is that a truly human diet places an emphasis on nutrient-rich, healthy eating tailored to the needs of the individual. The truest human diet, really, is one which recognizes, shifts and changes its components based on what is available and what it needs. This has been and will always be our species’ greatest strength – the ability to adapt and thrive. It is why we have an omnivore’s dentition, an omnivore’s gut, and omnivore’s tastes. An Omnitarian Diet Plan, designed towards the individual, may in fact be the most healthful way forward.
Sources
https://www.nature.com/articles/nature02734
https://www.nationalgeographic.com/foodfeatures/evolution-of-diet/
https://www.nationalgeographic.com/culture/food/the-plate/2014/04/22/prehistoric-dining-the-real-paleo-diet/
https://www.pnas.org/content/early/2010/12/17/1016868108
https://www.nature.com/news/art-of-cheese-making-is-7-500-years-old-1.12020
https://www.sciencedaily.com/releases/2013/06/130603163749.htm
https://blogs.scientificamerican.com/observations/early-meat-eating-human-ancestors-thrived-while-vegetarian-hominin-died-out/