Study: ancestral diet and lifestyle reverses diabetes
Source: O’Dea, K (1984)
Derby, Western Australia, 1983.
A group of ten indigenous Australians (with type-2 diabetes) revert to an ancestral diet and lifestyle for seven weeks.
The health of all participants improves—dramatically.
Using this paper as a case study, and leaning on further supporting literature, this article will seek to identify potential reasons for their health improvements.
Study results and implications
The authors conclude…
“In summary, all of the metabolic abnormalities of type II diabetes were either greatly improved (glucose tolerance, insulin response to glucose) or completely normalized (plasma lipids) in a group of diabetic Aborigines by a relatively short (7 wk) reversion to a traditional hunter-gatherer lifestyle.“
“The public health implications of these results are far-reaching: diabetes is potentially preventable in these people. It should be emphasized that although it is not necessary to revert totally to traditional lifestyle in order to prevent or attempt to reverse diabetes, certain characteristics of that lifestyle must be incorporated into any future public health programs…”
Characteristics of ancestral lifestyles that hold relevance to human health outcomes
Food
Movement
Sunlight & fresh air
Sleep
Earth
Stress
Let’s unpack them one-by-one.
The group mostly ate animal foods
As you probably know, animal foods are essential to human physiology.
Meat accounted for ~65% of all the food eaten by this group, and it seems to have done them well.
Beef, kangaroo, turtle, crocodile and fish feature prominently (see table below).
Source: O’Dea, K (1984)
Interestingly, despite meat being easily found in all three study locations, the group showed an inclination towards variety—and changed locations in order to find other food sources, like yams, fruits and honey.
This is an important point with practical implications—eating like a carnivore may supply all of our nutritional needs (energy & nutrients), but at the end of the day, humans do seem to enjoy variety.
The results of this study, however, provide further evidence to support the theory that ancestral diets rich in high-quality animal foods—especially meat—help restore metabolic health and promote optimal physiology in humans.
The group moved around often—at a slow pace
Many physiological processes are optimised by gentle forms of movement.
In the modern era of ‘exercise’ and ‘fitness’ culture, soft and gentle forms of movement—like walking—are not particularly well-received.
If we foolishly embrace the all-or-nothing mentality, then sure, activities like walking might seem like ‘not enough’ or ‘a waste of time’.
Too often do we judge the book by its cover, and not by the context.
Intense activity is not necessarily ‘better’ than soft, it’s just different.
For example, a post-meal walk significantly improves the body’s clearance of blood sugars and blood lipids—something which all humans, but especially those with diabetes or unfavourable lipid profiles, should be aware of.
The results of the study (improved blood sugar control, complete normalisation of blood lipids) seem to affirm the well-known physiological effects, and subsequent benefits, of frequent locomotion in humans.
The Aboriginals in the study hunted and foraged for their food—for up to 6 hours each day. This undoubtedly included some vigorous activity but gentler forms of movements constituted the vast majority of their total ‘exercise’ time.
We should no longer underestimate the power of walking, and other gentle forms of movement.
The group breathed a lot of fresh air and soaked up a lot of sunlight
How does it feel to breathe in pristine forest air?
Before widespread, oft-hasty, prescription of pharmaceuticals, fresh air and sunlight were used therapeutically for the treatment of a variety of medical conditions.
Think on your own experiences in Nature—your feelings are not worthless anecdotes—they are innate responses to the physiological effects of these environmental inputs.
Fresh, oxygen-rich air is indeed much different to the stagnant, recycled (and often polluted) air found in modern homes, offices and cities.
Out of sight, out of mind—what we cannot see with human eyes is too often overlooked.
For example, overexposure to heavy metals (found in our air, water and food) injure human physiology, burden our organ systems and overwork our detoxification pathways. Chronic exposure reliably leads to a host of negative health outcomes.
Have you ever passed through a cold, dark winter, and felt the warmth and aliveness that the spring sunlight brings?
On a more positive note, sunlight contains various wavelengths of light—blue, green, red, UVA/B, infrared and more—and each of these wavelengths interact with human physiology in various ways.
If the dose of sun exposure is appropriate, there seems naught but benefit on offer.
For example, UVB is used by the body to synthesise Vitamin D, which is essential for mood, bone health, and immune function.
Moreover, the evidence strongly suggests that sun exposure plays a key role in the prevention of various cancers and gastrointestinal tract diseases.
In hot and sunny climates like Australia, we have been taught to fear the sun instead of appreciating its necessity, and the benefits we may derive from safe exposure.
The Aboriginals in the study were wandering their lands in one of the most remote parts of Australia, unspoiled by the ravaging footprint of urbanisation. The water and air would have been entirely free from pollution, and the soil and vegetation untouched by pesticides or herbicides—as Nature intended, and as our ancestors experienced it.
The group slept during the hours Nature intended
In the modern era, when the sun goes down, we simply switch the lights on.
We’re also likely to stare into our phones, TVs, or Kindles, whilst sitting beneath our lightbulbs.
All of these modern technologies emit extremely bright wavelengths of light that mimic daytime sunlight.
Bright light exposure before bedtime disrupts our circadian timing (biological clocks), and is now a common cause of poor sleep quality among modern humans.
Sleep quality (but not necessarily quantity) is paramount to optimal health.
Poor sleep quality—from blasting ourselves with artificial light after the sun goes down—has many negative downstream effects.
Reconsider your evening routine and habits.
Improving sleep quality optimises human physiology and leads to systemic health improvements—immune function, brain function, body composition, recovery from physical activity… you name it.
The Aboriginals in this study didn’t have phones or TVs with them in the bush. We can also infer that they cooked on fires each day and likely went to bed when their bodies said so. It is not clear whether they had access to kerosene lanterns or other such lights, however, we can say that there was a definite absence of artificial light. The stars would have been incredible to behold. The Aboriginals would have woken up around dawn feeling very well-rested—something very few of us urbanised folk can relate to, given our predilection for bright lights and late nights.
The group were in direct contact with the Earth
There are a couple of things going on here.
1) Earthing optimises human physiology
Earthing has been shown to benefit the cardiovascular system, decrease inflammation, improve blood flow, improve blood pressure, improve heart-rate variability and positively modulate the Autonomic Nervous System.
Earthing—also called grounding—involves walking, standing, or sitting barefoot outdoors, swimming in the ocean, or any situation where the body comes into direct contact with the conductive surface of the earth.
Modern, urban environments tend to insulate humans from contacting the earth’s electrical fields.
This lack of contact is evolutionarily-inconsistent, and the scientific literature strongly supports our physiological need for it.
2) Exposure to soil-based organisms improves the diversity of our microbiome and optimises gut health
A single handful of healthy soil is home to more living organisms than there are humans on planet earth.
Humans don’t just need nutrients from food.
We also need exposure to microorganisms that live in the soil, grass, and trees.
We can try to mimic the effects of Nature by taking probiotic supplements, but really, it’s much more profitable to go stick your feet in the dirt on a regular basis—like these study participants did.
It is unclear whether the study participants were barefoot the entire time. It may be that they were, or that they wore shoes. Nevertheless, the Aboriginals would have been ‘grounded’ throughout the majority of the study; being in the water while fishing or catching turtles or crocodiles, sitting, and/or sleeping on the ground, touching the earth while digging for yams and so on.
The group were living a relatively ‘stress-free’ existence
The differences between modern, urbanised life and that of our ancestors are not limited to quality food, movement, fresh air, sunlight, sleep or earth.
It’s also about the fact that many of us live in busy, noisy, crowded environments. We live close to others, but often lack community and connection with them.
We engage in evolutionarily-inconsistent, stressful behaviours, like scrolling through social media, and being at the mercy of endless notifications.
Ping-ping.
Ding-ding.
Phone alerts raise our own alertness—until we sufficiently suppress this barrage of modern-day stimuli, we will forever be fighting an uphill battle to truly relax. This kind of stimuli feeds into our sympathetic nervous system, which keeps us switched on, and looking for problems to solve. To relax, we need to find ways to switch off, and instead, feed the parasympathetic nervous system.
How many distracting notifications have you received whilst reading this article?
Ping-ping.
Ding-ding.
It’s annoying, right?
Let me repeat that without the interruptions—ancient human physiology doesn’t seem to enjoy being wedded to extremely modern technology.
So, until we’ve evolved to do so, don’t leave your physiological fate in the hands of your phone.
The Aboriginals in this study had no access to modern technologies, such as smartphones. They had each other, members of their community, presumably on land that is culturally and spiritually significant for them. There was nothing to do other than forage, hunt, talk, laugh, tell stories, and be present with each other and their environment.
Ancestral diet and lifestyle dramatically improves human health and wellbeing
Humans are not destined to become diabetic, develop permanent gut issues, or die of cancer or heart disease.
These chronic, degenerative diseases are diseases of modernity.
They are preventable, and in many cases, reversible.
What this case study clearly reinforces is; that living more like your ancestors profoundly optimises your physiology.
And this will help you live a healthier, more robust, and fulfilling existence.
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References
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