Wednesday, January 6, 2010

The Old Way: Plant foods in the !Kung Diet

Some advocates of ancestral diets promote very low or no intake of plant produce, preferring to model their diet plans after some circumpolar tribes like Inuit (Eskimos) and Chukchi who eat almost nothing but meat.

I disagree with this approach because I don't think these circumpolar tribal diets represent the norm for humans in evolutionary time or among recorded hunter-gatherers. Humans originated in Africa, in an equatorial climate, where the environment provided plenty of edible plant products along with wild game.

When we look at observed equatorial hunter-gatherer diets, we find that the people get a significant portion of their energy (calories) from plant foods, particularly roots and tubers.

In the film Journey of Man (PBS, 2003), Dr. Spencer Wells, Ph.D. presents the story of his discovery of the genetic evidence that all modern humans have descended from a group of people who were ancestors of the people of the present-day Ju/wasi (aka !Kung or Bushman) tribe. Given this, the diet of contemporary Ju/wasi can probably give us important insight into ancient human diets.

In The Old Way (Sarah Crichton Books, 2006), Elizabeth Marshall Thomas describes the life of the Ju/wasi from her first-hand experience living with them. Regarding their diet, Thomas reports:

"The meat of big game, large harvests of nuts, and large, delicious windfalls such as palm hearts were profoundly welcomed by all concerned, but months could pass before the people obtained these kinds of foods, foods that required sharing. Most of the time, people ate the berries, roots, and slow game obtained by ordinary, everyday gathering, usually but not necessarily done by women..." (p. 108)

"By far the most important staple foods of the Ju/wasi were roots––the twenty-five kinds of bulbs, rhizomes, corms, and tubers. The other foods were either small, such as berries, or scarce, such as truffles, or seasonal, such as certain fruits or the spinachlike leaves. Roots were the everyday meal, and even in some cases were sources of water...For the Ju/wasi as for the people of the past, roots were excellent nutrition, and best of all, unlike fruits or berries, could be noted in one season and gathered in another, as few other creatures were competing for them." (p. 110)

I want to emphasize that meat played an important role in the Ju/wasi diet. They highly valued meat. How much? I'll let Ms. Thomas speak again:


"Meat united people. A meal of life-giving meat was meant for all. On the day that Short/Kwi came home dragging the heart-shot ostrich that had charged him, the women in the camp stood up and started dancing, just from the joy of seeing the eat and from having a man like Short/Kwi living among them, bringing a bounty of life-giving food to share with his people. My mother wrote: 'Women bring most of the daily food that sustains the life of the people, but the roots and berries of the Nyae Nyae Ju/wasi are apt to be tasteles and harsh and not very satisfying. People crave meat. Furthermore, there is only drudgery in digging roots, picking berries, and trudging back to the encampment with the heavy loads and babies sagging in the pouches of the leather capes; there is no splendid excitement and triumph in returning with vegetables. The return of a hunter from a successful hunt is vastly different. The intense craving for meat, the uncertainty and anxiety that attend the hunt, the deep excitement of the kill, and finally, the eating and the satisfaction engage powerful emotions in the people.'"


The Ju/wasi diet may give us important insight into the ancestral diet of humanity prior to the exodus from Africa about 50,000 years ago. Although I have no doubt it contained plenty of meat and fat, it probably had much more plant food than the Inuit diet. In Africa, our ancestors most likely would have found enough plant foods to make them a significant portion of their diets, just as did the Ju/wasi described by Thomas.

The Old Way gives the reader a first hand, nearly insider account of hunter-gatherer life. I highly recommend it to students of paleo diet.

35 comments:

Aaron Blaisdell said...

Thanks for sharing! It's amazing how much diversity in food types exists among different HG diets. I have observed for myself that starchy plants, such as potatoes and sweet potatoes are very well tolerated and don't seem to cause me to veer away from feeling satiated and healthy. Thank G*d, 'cause I love potatoes, french fries, etc.! Especially when I cook them in rendered duck fat or coconut oil or bacon drippings or ghee.

Todd Hargrove said...

What fantastic book. Not just for the diet info, but for beautiful writing about an amazing (and sad) subject.

I wonder whether how long the Kung have been in an area where it is so hard to scrap out a living. Perhaps they were able to eat a little more meat before being forced into a such a tough area.

rosenfeltc said...

Thanks for the post. I'm wondering though, is the average meat that they eat less fatty and more lean?

Also does it mention in the book if they tended to feast for dinner or if they munched on some nuts and fruits during the day?

Miki said...

I agree with Todd. Present day HG are occupying the worst pieces of land on the planet. The Hadza is a good example and so are the !kung. Agricultural societies are always more organized and have been pushing HG off of good lands for the past 10K years.The present day !kung can only serve as an example for survival, not for an optimal diet. This doesn't mean that we can't tolerate carbs. It just means that they are not necessarily optimal for health and longevity.

Andrew S said...

I think the balance between meat and other stuff for humans follows the common diet balance of all wild animals: in times of plenty, a species grows in population and eats the preferred food. When that food is scarce, they resort to alternatives and reduce in population.

The !Kung provide a snapshot of one culture at one point in a sinusoidal diet cycle. High point? Low point? It's hard to tell, and at some point it seems like food reenactment.

madMUHHH said...

Great to see this. I've basically given up low-carb, because it really seemed to actually damaged my body quite a lot. So, I started incorporationg more starchy vegs and (sweet) potatoes. Glad to see that I can still eat "paleo", probably even more paleo than many VLCers and carnivores out there.

Don said...

Todd and Miki,

I agree that !Kung certainly had richer habitat before getting surrounded by agriculturalists, but richer habitats have both more animals and more plants.

So Miki, your argument cuts both ways...i.e. yes, !Kung would have greater access to animal foods if they weren't surrounded by agriculture, but they would also have greater access to wild plant foods, particularly roots and tubers.

I would like to see the evidence that a plant-food free, starch-free diet is optimal for health and particularly longevity. Certainly low-carb is NOT a feature of the diets of the Okinawans, who have the longest HALE of any group currently under study.

And, just as I have never seen a report of a vegan centenarian, I have yet to see report of a zero-carb centenarian. Please provide evidence if possible.

Don said...

rosenfeltc,

They fast and feast, they eat little or nothing during the day while hunting and gathering, then prepare a communal feast in the evening.

They have mores such that certain prized foods (meats, nuts, palm hearts, and others) MUST be shared with the group, whereas less important foods (berries, small game) belong to the person who gathers them, who can eat or share as much as s/he likes.

In practice, it appears from Thomas's account that most foods get shared, if quantity is great enough to do so.

Don said...

rosefeltc,

The wild game of Africa tends to carry little fat, although it varies with the season. Sometimes they had more, sometimes less.

Hence, probably human physiology is best adapted to some variation in food intake...sometimes more and sometimes less of each macronutrient.

Don said...

One general commment -- if you live in a rich equatorial climate undisturbed by agriculture, you would have access to lots of game and plant foods.

In such a niche, one could almost always collect plant foods. Although the caloric return for investment on a single hunt would almost always exceed the return for gathering plants (because of the lower caloric density of plants), a trip gathering would almost always bring back food, whereas a trip hunting would sometimes succeed, sometimes not.

If a species has the ability to both hunt and gather, especially via division of labor (male/hunt, female/gather), I very much doubt that the individuals would refuse gathered foods (plants) in case a hunt failed.

My point is that even under the best conditions, the caloric delivery of hunting ebbs and flows, whereas that of gathering (including collecting small game) remains fairly constant.

Under such circumstances, an omnivorous species would naturally adopt gathered plant foods and small game as its basic diet, while also making an effort every day to obtain the prized large game, sometimes succeeding and sometimes not.

To repeat, it seems to me that this would play out even in the richest of habitats, simply because of the lower reliability of hunting.

If we were cats, we would essentially have no choice, we would eat meat or fast. But we are not cats, we can eat plant foods.

I have yet to see any advocate of the "humans-are-pure-carnivores" hypothesis give me a good reason to believe that prehistoric human hunters were either a) infallible or b) that they refused to eat plants when hunting failed to return meat-and-fat.

Let me put it another way. If you took all the game out of Africa, lions and tigers would starve to death/extinction. You wouldn't find those cats "fall back" on plant foods. However, if you reduce game supplies available to humans, they do "fall back" on plant foods. It seems to me that this demonstrates that our species is by nature omnivorous -- that we have equipment for processing both plant and animal foods. And this suggests that perhaps we may require both plant and animal foods for best of health.

rosenfeltc said...

I agree, I think that this with your primal potatoes post on amylase really does signify the importance of tubers in our ancestor's diet. However, I still think the whole RDA nutrition of trying to meet 100% of every vitamin is a bit stupid. How about just some fatty meat and potatoes? lol

Greg said...

I don't know if my last comment got lost- the question becomes what do we choose to eat in our food rich environment given we no longer have the constraints of the hunter/gatherer. It would be interesting to see any evidence of a hunter/gather preferring a plant to meat.

madMUHHH said...

Definitely agree Don.

And also - even though this isn't entirely on topic - I believe many people in the paleo scene make a similar people that so many people did/do with cholesterol. They think that high cholesterol or in this case insulin is bad and should be avoided at any cost. But personally, I do not think that insulin itself is the problem, it's the excess insulin that is caused by HFCS, refined grains etc. that is totally out of proportion to the carbohydrate content that's bad, not insulin itself.
This is why I think that there really isn't much of a problem incorporating tubers into your diet. They may cose a bigger insulin release, but won't at the same time drive blood sugar too low. As far as I'm concerned some doctors even "prescribe" potatoes to diabetics to keep they blood sugar high enough throughout the night.

madMUHHH said...

@Greg:
I don't think it really is important to look at what a hunter/gatherer WOULD eat, or at least not viewn in the context of finding an optimal diet if there is any.
The question rather is what a hunter/gatherer DID eat as this is most likely what we are best adapted to. It's just like with intermittent fasting. It has quite some health benefits, but not because paleo man preferred to do this, but rather because he simply had to do this in one way or another, thus leading to a certain genetic adaption to it.

Don said...

Greg,

"It would be interesting to see any evidence of a hunter/gather preferring a plant to meat."

Even if no such case exists, this would not establish that humans are adapted to meat-only.

I have had some women tell me that they prefer plants to meat. But how are their preferences shaped?

I have also had parents present to me their problem with their children preferring sugar to meat. Doesn't follow that sugar is the best diet for those children.

Hunter-gatherers prefer meat to most other foods (although I think !Kung consider mongongo nuts as desirable as meat) partly because meat (and nuts) has the highest energy density of the foods available to them, giving them the most pleasure, the guide to meating energy needs.

But that doesn't mean that the foods they rate as less preferable don't provide important nutrition, or that a diet composed only of the preferred foods is superior to one containing a mix.

People probably prefer to sit on their asses all day, but this isn't best for the organism long term.

Don said...

madMUHHH,

Right on. We are adapted to what paleo people did do, NOT what they would have preferred to do.

Don said...

Honey provides a good example of how hunter-gatherer preferences don't give us the guidance we need. Hunter-gatherers definitely went out of their way to get honey, and had a strong preference for it, and probably would have preferred to eat it every day, in large amounts...but they couldn't.

To a great extent, it is the imposition of our preferences on our food supply that has led us to our SAD diet and all its harmful effects.

Greg said...

I definitely agree that the starting point for health is what our paleo ancestors did, not what they wanted to do.

What I was trying to get at with the hunter gatherer preference for meat is that as the human population grew, hunter gatherers became more constrained. And in recent time the hunter gather populations have been pushed into the land that is least productive.

So in the case of a resource-constrained activity like eating meat, if we go back farther in time to when there were less constraints, we may find that what they wanted to do more closely resembled what they did.

But all of this is just a starting point- it doesn't really answer the question: what is *optimal* for us to eat in our food rich environment?

Ryan Koch @ Health Matters to Me said...

I read an anthropoligical study on the Bushmen once in which the author asked the people what their preffered foods would be if they had the choice to eat whatever they wanted. The reply went something like this:

-Meat for satiety
-Mongongo nuts for strength
-Wild oranges to satisfy thirst

Flowerdew Onehundred said...

Great post, Don.

I think it's likely that our ancestors ate tubers, and I see little reason not to include sweet potatoes in mine. Of course, I adore fatty meat and limit fruit and tubers, but I'm not interested in banishing them from my diet.

Don said...

Ryan,

I would like it if you could provide a reference for that. It makes sense to me but I want the source. If true, it illustrates that preferences arise from needs, and that no one food can meet all needs, at least for !Kung.

Optimal foraging theory is an outiders view of how H-Gs choose to invest time based on a sole criterion, energy-density of foods. But inside the tribe, they may invest in ways that don't fit optimal foraging theory because they have to meet needs other than energy requirements. Meat won't quench thirst and oranges won't provide satiation.

Ryan Koch @ Health Matters to Me said...

I read it a while back in a used book store (Bookman's in Tucson). It was a thin book and was part of a series of studies of tribal peoples all over the world. This may be the right book/series:

The Dobe Ju/'Hoansi (Case Studies in Cultural Anthropology)

If you go to Bookman's, check out the anthropology section and you may find an older version of the book.

Ned Kock said...

I tend to agree that meat-only diets may not be the best in terms of promoting longevity and overall health, even though today they seem a much better choice than the mainstream low fat diets rich in refined carbs and sugars.

Vilhjalmur Stefansson, in his discussion of longevity among the Inuit, implied that it was not that high; certainly not even close to the levels observed in the Ryukyu Islands.

There is also the interesting factoid that Stefansson, known for eating only meat for long periods of time, died at around 82 from stroke; whereas Ancel Keys, whose diet was more like the Mediterranean diet, died just short of 101 years of age.

Among our ancestors are the Australopithecines, who were vegetarian. The first hominid group in our lineage to eat meat was probably Homo habilis, and then Homo erectus with higher consumption.

So, even though we undoubtedly have many adaptations that are geared at meat-eating, we probably still have some associated with our more distant vegetarian past.

Todd Hargrove said...

I'm curious how much honey HGs would eat if given ad libitum access. Maybe they would self limit in a healthy way just based on taste.

A restaurant is basically a chance to eat whatever you want and people don't order a huge bowl of honey. I think its interesting that traditional restaurants all over the world offer meals that are roughly very similar in the breakdown of basic food sources: a piece of meat or fish, an almost equally sized starch, such as a potato or rice, and a slightly smaller bunch veggies. If you randomly order a meal anywhere in the world it will probably roughly conform to this pattern. Maybe HGs given ad libitum access to whatever they wanted would choose similar meals. Perhaps we only start to make poor choices with foods when eating neolithic foods, sch as gluten grains, processed carbs, sugar, etc.

All speculation of course.

Chris D said...

Surprised that no one has linked to a Cordain paper specifically on this topic. "Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets"
http://www.ajcn.org/cgi/content/abstract/71/3/682

The majority of existing hunter gatherers worldwide consume a fair amount of fruits and vegetables. There is no question about this.

Don said...

Ned,

For example of adaptations to plant foods, we need look no further than our saliva and its amylase content. This is a very old adaptation as indicated by its presence in chimps as well.

Todd,

I have noticed the same thing...meat, starch, vegetables seems a universal human dietary pattern when people have the choice. And if you look at macronutrient proportions o free living populations, whether looking at vegans or the French, people tend toward about 15-20% protein, 40-45% fat, and 40% carb. I think neolithic foods and what I call "magic" foods (high sugar + high fat, like donuts, pastries, etc.) misguide the natural guidance system.

Your probably right, given unlimited access to honey, H-Gs probably wouldn't eat only honey, but I think that they might eat it more frequently than might be optimal.

Greg said...

Chris, thanks for the Cordain reference. It is important to remember that any attempt to decipher paleo history is going to be full of guesswork. Traditionally, Cordain and Eaton have been quite wrong on the diets of hunter/gatherers because they didn't take into account that hunters always went after the fattest animals and ate all of the available fat of the animal, and would even sometimes discard animals that were lean. There is a discussion of this phenomenon in the paper, but I still doubt it is being taken into proper consideration.

Also according to the paper, the Ethnographic Atlas listed 20% of hunter gather populations as > 86% of calories coming from animal food. So plant consumption may have occurred in a majority of recent hunter gather populations, but it was not essential for the great health of the Inuit or Masai.

Chris D said...

@Greg

I read the wholehealthsource blog post commenting on the underestimation of fat in this paper.

Judging them to be quite wrong is a bit strong for my taste. I am unaware of anything resembling a comprehensive review of animal fat consumption of HGs; food scarcity may cause consumption of lean animals or all protein tissue at certain times.

Full text of the aforementioned paper here

I also see little evidence to suggest that HGs who get the majority of their calories from animal based sources to be healthier (or less health) than other HG cultures on average.

What would be interesting is some evidence on HGs who live in environments rich enough in game to eat 85%+ calories from meat, and ask them why they do not consume only animals.

Sanjeev said...

Hey don.

There's been a spate of recent theories that mitochondrial proliferation is protective, and all the stuff that causes mitochondrial proliferation is stuff that extends lifespan (but not proven in humans) - calorie restriction, low glucose (extended worm lifespan, increased mitochondria) and high fat when there's no fructose/sucrose around.

So the first question for you is, what's your take on this developing mitochondrial hypothesis.

Second, I'm curious what you think of Jicama - is it a new world food to avoid or close enough to potato / sweet potato to be a good addition?

I like it the couple of times I've had it because it's edible raw - a subtle taste and crunchy, with next to ZERO preparation time.

It has a lot more fiber than sweet potato though, and I believe it did not exist outside Mexico until recently, thus my concern about whether it's similar enough to a true ancestral food, or whether it contains any new world toxins.

I've been on a low carb diet, bordering on zero carb for a long time and lost a lot of weight. I've tried now 3 times in the last year to introduce carbs back in and every time I just seem to pack on the pounds quickly and have to cut the carbs out for a month or 2 to get my appetite and hunger under control. In the next cycle I'm going to try introducing starches and keep the sweeteners way down, and I'm looking at yams and jicama.

gallier2 said...

@Todd Hargrove

Your restaurant observation is not universal. I've been in Africa several times (Gabon and Comoros) and I can tell you, that while the more expensive restaurants follow that pattern (because these are european influenced ones), the traditional ones for the local people, where rarely a white (mzungu) is seen do not follow it. The meat/fat and starchy part are split 50/50, the vegetables are only used as spices for the sauces (like one would use oignon or carrots in gravies).
Here a list of typical african restaurant fare:
In Gabon
poulet yassa (rice + chicken in lemon/oignon sauce)
tchep (heavy fatty rice + fish/chicken + vegebtables (carrots, kassava root, cabbage) but not mcuh of it.
bushmeat niembwe (the sauce made of palmtree nuts, extremely fatty; meat of any species around, I've seen elephant trunk, gazelle, crocodile, monkey and others)
for breakfast, coupé-coupé which is roasted briskett served with powdered chili and a slice of bread.
On Comoros
Zebu brochettes,
Ndrovi y Nyanzi: national dish consisting of cooked green bananas with sheep tripes.
etc..

This was only to show that eating a lot of vegetables is not universal. Meat, fat and starches yes, vegetables no.

Richard Nikoley said...

Fabuouls, Don, as always.

Yep. "Paleo" is Kitava to Arctic circle and all in between, eating real food. Neither extreme is probably optimal, it's good to know it's workable, but every individual has to find their own optimal.

I have enjoyed adding back a bit more carb via potato and other roots. Far better than fruit in my view.

blogblog said...

The life expectancy statistics of Japan (including Okinawa) are completely worthless. Deaths are simply not reported by relatives who continue to claim pensions.

There are more than 230,000 missing centenarians in Japan. They are presumably dead.

http://www.bbc.co.uk/news/world-asia-pacific-11258071

blogblog said...

The Kung! simply show that some people in highly marginal area subsist on a diet high in plant materials. To say they some how represent an authentic HG diet is totally unjustified.

blogblog said...

The Kung!, Hadza and Kitivans typically eat one large evening meal and fast for around 20 hours a day.

Eating one large high carbohydrate meal a day means that nearly all the starch is stored as saturated fat. The saturated fat is then then used to supply energy during the fasting period.

In reality Kitivans, Kudzu and Kung! get most of their their energy from their body fat not starches.

Don said...

Blogblog,

Have you read any basic texts on human nutritional physiology?

If you did, you would know you are wrong. That starch gets stored as glycogen. Numerous studies have shown that the body rarely converts excess carbohydrate into body fat, and certainly not under conditions of intermittent fasting combined with exercise which reliably depletes glycogen stores.

The liver can hold ~100 g of glycogen and the muscles ~300-400 g. That means if you deplete glycogen by exercise and fasting as teh !Kung do, you can store up to 500 g of EXCESS (not immediately required) carbohydrate as glycogen.

You are simply wrong, passing around low carb urban legends.