“Bread is the staff of death.” — Dr. Emmet Densmore, American physician 1837-1911

Imagine: it’s the Paleolithic Period (about 2 million years ago), and you and your sister are sitting in a cave watching a storm coming across the horizon. You decide to stay on the safe side and wait out the weather. Before long, the clouds part, the sun peeks out from behind their protection, and the two of you start foraging for a snack. Sunlight gleams off of the dew of the plants, and the air smells fresh and clean. 

Suddenly, a familiar leaf pattern and a flash of deep, bright red catches your eye. It’s a wild strawberry plant, the first one you’ve seen in months. They must be back in bloom! You carefully pick the ripest of the delectable fruits and place them in a small pouch for safekeeping. They’ll make the perfect dessert for your meal of fish, mushrooms, and acorns.

Before the advent of farming and animal husbandry, this was a likely scenario for securing food for humans in the paleolithic era. Most archaeological and anthropology research suggests that early modern humans, as well as their ancestors, were hunter-gatherers whose diets consisted of foods that could be caught, trapped, killed, picked, shaken, or collected. 

Today, thanks to a modern understanding of this “paleo diet”, the presumed diet of hunter-gatherer has become an immensely popular food trend. In this post, we’ll take a look at this diet, the scientific evidence for it, and benefits that exist for those that adhere to this method of eating.

 

What is a Paleo Diet? 

The Paleo Diet describes food intake that consists primarily of foods that would be found in the wild before the development of modern agriculture. In other words, it is based on the hunter-gatherer diets, also called paleolithic, Stone-Age, or caveman diets of our ancestors.

“Paleo” is short for the word “Paleolithic,” and it refers to the time between two million years ago and 10,000 years ago that ushered the evolution of modern Homo sapiens. 

The diet includes animal products (meat, internal organs, bone marrow) except for dairy and plant products (fruits, nuts, roots, and stems) except for cereal grains and legumes. Paleo diets exclude refined products like sugar and flour, cereal grains like wheat and barley, dairy products, legumes like beans and lentils, and extraction products like coffee and alcohol.

Paleo diets were first described in the medical literature in the mid-1970s but gained little interest until research in the 1980s and 1990s showed that a sedentary lifestyle plays a significant part in the development of several diseases. This lifestyle was created first by farming 10,000 years ago, increased drastically by the industrial revolution of the 1800s, and sharply accelerated by the rise in availability of fast food starting in the 1950s. These sociological events made humans less reliant on covering long distances or exerting substantial effort for food, centralized the food supply, and made more food available for cheaper prices. 

 

Wait — did you say no coffee or alcohol? Why is this diet so popular again?

 

In 1985, medical anthropologists Boyd Eaton and Melvin Konner wrote about the benefits of the paleolithic diet on early modern humans, and its contrast to modern Western calorie consumption, in one of the world’s most prestigious and influential medical journals: the New England Journal of Medicine.

Over the next 25 years, the fast-food revolution, in particular, came under increasing scrutiny for its effects on health. Widely read books like Fast Food Nation and The Omnivore’s Dilemma, as well as popular documentary films like SuperSize Me, were highly critical of the widespread availability of processed foods and often advocated for plant-based diets, including that of the hunter-gatherer. Authors and celebrities alike advocated for these diets based on the idea that humans had evolved to consume calories most optimally through the paleo diet rather than through the modern Western diet. 

 

How is the Paleo Diet different than any other diet?

Like other diets, including the Mediterranean diet, the paleo diet has some basic features: 

● Eating primarily plant-based foods

● Refraining from refined sugar 

● Excluding processed foods

Unlike other diets, the paleo diet has an additional mandate: adherents to this diet are to avoid food that would not naturally be found in the wild. That means avoiding foods that are primarily associated with animal domestication and agriculture. 

Proponents of paleo diets state that we should eat foods that are wild and natural because the human species hasn’t had enough time to adapt to the current human food consumption patterns adequately. Critics of the diet note that there isn’t clear agreement on exactly which foods were consumed by pre-agricultural humans, and that these foods were likely to vary widely due to climate, topography and other factors. 

 

What evidence is there that the Paleo Diet works?

For all of the popularity of the paleo diet since the 2000s, there is relatively little scientific evidence for or against its usage. Studies have generally been low-power (either the study design wasn’t very rigorous or not many people participated). There is data that the paleo diet has short-term effectiveness in reducing short-term potential importance for health: blood glucose, waist circumference, resistance to insulin and body mass index. However, at least one study has shown that the paleo diet isn’t any more effective than other plant-based diets at creating long-term changes. 

Keep in mind, though, that adhering to a paleo diet will beat the typical Western diet since it means cutting out highly processed foods. If you cut out foods high in sugar and low in nutrients like omega-3 fatty acids, vitamins, and minerals…you’re bound to see health improvements!

 

What do I have to consider if I’m going to try the Paleo Diet for awhile?

If you’re considering paleo as a weight-loss diet or healthy lifestyle choice, consider the following: 

● Cost: Paleo diets usually call for fresh rather than frozen or canned foods, which are typically more expensive.

● Nutritional needs: Paleo diets exclude legumes, dairy, and grains, which are major sources of B and D vitamins, as well as of several minerals. So, be sure to vary your menu to get as many nutrients as you can!

● Sustainability: For some, it may not be practical or beneficial to exclude entire food groups from their diets. For others, the benefits may feel natural, and the diet can be integrated into their lives relatively easily. 

 

References:

• Johnson, Adrienne Rose (2016). Paleo Diets and Utopian Dreams. Skeptic. 21 (3): 11–12.
• Challa HJ, Uppaluri KR. Paleolithic Diet. [Updated 2019 May 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan.
• Berggren, T, Marchand R, Barrios A, et al. (2018). Nutritional and Health Info Sheet: The Paleo Diet (for health professionals). Department of Nutrition, University of California Davis
• Harvard University School of Public Health. (2019). Diet Review: The Paleo Diet.
• Otten J, Stomby A, Waling M, et al. (2016). Benefits of a Paleolithic diet with and without supervised exercise on fat mass, insulin sensitivity, and glycemic control: a randomized controlled trial in individuals with type 2 diabetes. Diabetes/ Metabolism Research and Reviews;33(1).
• Mellberg C, Sandberg S, Ryberg M, et al. (2014).  Long-term effects of a Palaeolithic-type diet in obese postmenopausal women: a 2-year randomized trial. European Journal of Clinical Nutrition. Mar;68(3):350.
• Masharani U, Sherchan P, Schloetter M, et al. (2015). Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes. European Journal of Clinical Nutrition;69(8):944-948.
• Frassetto, L., Schloetter, M., Mietus-Synder, M. et al. (2009).  Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. European Journal of Clinical Nutrition 63, 947–955.