Paleo Diabetic

I scored of copy of “A multidisciplinary reconstruction of Palaeolithic nutrition that holds promise for the prevention and treatment of diseases of civilisation” by RS Kuipers, JCA Joordens, and FAJ Muskiet. I’m not going to review it here. I’m just assembling some interesting “facts” for my files, so this could be boring. You won’t offend me much if you stop reading now.

This paper is from the University Medical Center Groningen and Human Origins Group (Faculty of Archaeology, Leiden University), both in The Netherlands. It’s 23 pages long, not counting the 450 references.

I’ll following the spelling conventions of the paper’s publisher.

Introduction

“…our genome has remained basically unchanged since the beginning of the Palaeolithic era.”

“Since the onset of the Agricultural Revolution, some 10 thousand years ago, and notably in the last 200 years following the start of the Industrial Revolution, humans have markedly changed their dietary habits. Consequently, it has been advocated that the current pandemic of diseases of civilization results in part from the mismatch between the current diet and our Palaeolithic genome.”

These are some of the diseases that may result from the mismatch of our Palaeolithic genome and modern lifestyle (including diet): type 2 diabetes, high blood pressure, osteoporosis, fertility problems (polycystic ovary syndrome), pregnancy complications (pre-eclampsia, gestational diabetes), some cancers (colon, breast, prostate), heart disease (such as coronary artery disease), major and postpartum depression, autism, schizophrenia, some neurodegenerative diseases (Parkinsons disease, Alzheimer’s disease). [Sorry, Dr. Cordain – no mention of acne. And I wonder about dental and eye problems.]

Evolutionary Medicine

“Many, if not all, diseases can become explained [sic] by both proximate and ultimate explanations. The science searching for the late explanations has become known as ‘evolutionary medicine.’ Unfortunately, modern medicine deals mostly with proximate explanations, while ultimate explanations seem more prudent targets for long-time disease prevention.”

The term “evolutionary medicine” was coined by Randolph M. Nesse and George C. Williams in the early 1990s. It’s also called Darwinian medicine.

“…about 20% of modern hunter-gatherers reach at least the age of 60 years.”

After the transition to the Agricultural Revolution about 10,000 years ago, life expectancy fell from about 40 years to about 20 years. This is astounding news to me, assuming it’s accurate.  (Remember that for most of human existence, infant and child mortality has been very high. If an infant dies at 6 months old and an adult dies at 40 years, average life expectancy for the two would be about 20 years.)

Average life expectancy among modern hunter-gatherers is about 40 years—same as it was for students of the Harvard College class born in 1880.

Life expectancy in the Neolithic era was stable until the late 18th century, rarely exceeding 25 years in civilized nations.  At that point, life expectancy started to improve dramatically thanks to sanitation, water and food hygiene, immunizations, and quarantine practices. (Thomas Jefferson was the third president of the U.S.  His wife Martha had six children but only two survived to adulthood.)

The earliest species in the genus Homo appeared about  two million years ago.   Homo sapiens appeared about 200,000 years ago in south or east Africa. Several different hominin lines co-existed with modern humans.

The current world population of humans may be derived for only 1000 or so individuals that survived a decimating event.

The ability to store fat is one of the things that differentiate us from other primates.

Hunting and Our Ancient Diet

The composition of the early human diet is still hotly debated.

In modern hunter-gatherers, only about 30% of diet energy is derived from hunting, with the rest coming from gathering plant food and aquatic animals.

In contrast to the arid, hot, iconic savanna, “…the combined evidence strongly suggests that early hominins frequented the land-water ecosystem and thus lived there.” If rainfall and other conditions allowed, there would be wooded grasslands.

“…the proportion of the human gut dominated by the small intestine (>56%) suggests adaptation to a diet that is highly digestible, indicating a closer structural analogy with carnivores than to [animals that eat leaves and fruit].”

“The data of combined studies of early hominins and the more recent hominins suggest a gradual increase in dietary animal protein, a part of which may derive from aquatic resources. In the more recent human ancestors, a substantial part of the dietary protein was irrefutably derived from marine resources, and this habit was only abandoned in some cases after the introduction of agriculture at the onset of the Neolithic.”

Sea levels have risen over the past 17,000 years, up to 150 meters.

“In conclusion, there is ample archeological evidence for a shift from the consumption of plant towards animal foods.”

“For a long time period in hominin evolution, hominins derived large amounts of energy from (terrestrial and aquatic) animal fat and protein. This habit became reversed only by the onset of the Neolithic Revolution in the Middle East starting about 10,000 years ago.”

“The Homo genus has been on earth for at least 2.4 million years and for over 99% of this period has lived as hunter-gatherers.”

“We conclude that gathering plays, and most likely always played, the major role in food procurement of humans. Although hunting doubtlessly leaves the most prominent signature in the archaeological record, gathering of vegetables and the collection of animal, notably aquatic, resources (regardless of whether their collection is considered as either hunting or gathering), seems much easier compared with hunting on the hot and arid savanna. We suggest that it seems fair to consider these types of foods as an important part of the human diet, unless proven otherwise. Conversely, while hunting might have played a much more important role at higher latitudes, dietary resources in these ecosystems are rich in n-3-fatty acids (for example, fatty fish and large aquatic mammals), while the hominin invasion of these biomes occurred only after the development of more developed hunting skills.”

Even though traditional Maasai showed extensive atherosclerosis with fibrous changes and lipid infiltration, they had very few complicated arterial lesions and rarely had clinical cardiovascular disease events.

The Agricultural and Industrial Revolutions

“Contrary to earlier belief, the advent of agriculture coincided with an overall decline in nutrition and general health, but at the same time provided an evolutionary advantage since it increased birth rates and thereby promoted net population growth.”  [Both supporting references are from CS Larsen.]

With the advent of the Industrial Revolution, nutritional quality and general health declined even more rapidly.

“Among the many dietary and lifestyle changes are: a grossly decreased n-3:n-6 fatty acid ratio, the combined high intakes of saturated fatty acids and carbohydrates, the introduction of industrially produced trans-fatty acids, reduced intakes of n-3 and n-6 long-chain polyunsaturated fatty acids, reduced exposure to sunlight, low intakes of vitamins D and K, disbalanced anti-oxidant status and high intakes of carbohydrates with high glycaemic indices and loads, such as sucrose and industrially produced high-fructose maize syrup.”  [Aren’t we eating more n-6 fatty acids, not less?]

Potential Benefits of a Palaeolithic Diet

The authors conclude with a review of the few medical scientific studies of Palaeolithic diets in modern humans. These are the ones by Frassetto, Osterdahl, Jönsson, and Lindeberg. I’ve already reviewed those here.  They missed O’Dea and Kerin’s study.

My Overall Impressions

This article seems very well researched.  It lays out a logical framework for the discipline of evolutionary medicine and should spur further clinical research.  It’s well worth a read if you have more than a passing interest in paleo lifestyle theory.

Bear in mind I’m not a paleontologist, anthropologist, paleo-anthropologist, or archeologist.  So caveat lector.

Steve Parker, M.D.  (B.S. degree in zoology)

Reference: Kuipers,RS; Joordens, JCA; and Muskiet, FAJ. A multidisciplinary reconstitution of Palaeolithic nutrition that holds promise for the prevention and treatment of diseases of civilization. Nutrition Research Reviews, 25 (2012): 96-129.  doi: 10.1017/S0954422412000017

PS: The Paleolithic diet is also called paleo, ancestral, hunter-gatherer, Stone Age,  Old Stone Age, and caveman diet.