Are Acorns, Wild Foods, And The Paleo Diet Bad For Teeth? Here’s What The Research Really Says


Source: PNAS

NPR recently published an article entitled “Looks Like The Paleo Diet Wasn’t Always So Hot For Ancient Teeth” (1). In it, author Christopher Joyce summarized the results of a new study regarding hunter-gatherers and dental caries (cavities).

Up until now, it has been hypothesized that the shift from hunting and gathering to a life based on farming and agriculture correlated with an increase in dental decay.  This new research, published in the journal PNAS, challenges the notion that hunter-gatherers were largely free from dental problems and instead suggests that a particular diet of wild foods can in fact lead to poor oral health (2).

If you haven’t read the NPR piece, no problem.  Here’s the gist:  Archaeological evidence from a Moroccan cave revealed the remains of a hunter-gatherer population that existed between 12,000 – 15,000 years ago.  Archaeologists were astonished to discover a very high rate of dental caries among the bodies, claiming that acorns may have been the culprits.  Acorns, according the study’s author, are very high in carbohydrates, and with their sticky texture can adhere to teeth.  Dental decay is the ultimate result.  This is the earliest discovery of dental caries in a population, challenging the belief that the paleo diet is inherently healthy.

End summary.

Now, it would be easy to address the points Joyce makes regarding the paleolithic diet and
lifestyle – that Stone Age life was “certainly” brutal and short, that there is one single paleo diet, and that saber-toothed cats were maniacally running around everywhere – but it’s not my intention to rebut these particular issues.

Fortunately, I was able to access the original study published in PNAS, and would like to reveal what the researchers actually discovered.

As it turns out, acorns weren’t the only botanical remains found.  Twenty-two different plants were discovered, including juniper, pine nuts, pistachio, wild pulses, wild oats, goosefoot, ephedra, rose, and elderberry.  Sure, acorns outnumbered the other plants, but nowhere in the NPR article is another species mentioned.  The researchers even specifically stated that carbohydrates found in wild pulses and wild oats may have contributed to the high prevalence of dental decay.

But let’s just assume, for the time being, that acorns were the major cause of the dental caries.  The holm oak acorns discovered (Quercus ilex) are reported to be low in tannin content.  Tannins are astringent compounds that can interfere with protein and mineral absorption and, unless action is taken to mitigate their effects, can be detrimental to the human body.  A major finding, mentioned nowhere in the NPR article, is that the acorns were thought to have been eaten raw.  According to the study:

“The rarity of charred seeds indicates that acorns were consumed raw or underwent an initial processing stage that did not involve the use of fire.”

Yes, the individuals may have used fire later on in their preparation of acorns, but the possibility exists that they were eaten raw.

Why does this matter?  Acorns are almost always processed in a particular way to increase edibility.  Ethnobotanical research reveals that clay, lye, lime, and water have all been used to decrease the tannin content of acorns, followed by the addition of heat.  Even though holm oak acorns are low in tannic acids, wild food experts still recommend that all acorns be leached prior to consumption.  Arthur Haines, a botanist who runs the Delta Institute of Natural History in Maine, writes (3):

“Despite what you may have been told, all acorns should be leached prior to consuming them in any quantity.”

There isn’t much evidence to support raw acorn consumption by healthy, indigenous populations.  Rather, what we do find is that those who process acorns through proper leaching and cooking often exude the qualities of superb health, with healthy teeth and bone structures.  Tannic acids affect protein and mineral absorption, and may alter the availability of certain compounds necessary for healthy teeth and bone formation, thus leading to dental caries.

The study isn’t saying that leaching was always omitted.  It is possible that the North African hunter-gatherers leached the acorns and reduced the tannin content.  But heat could have reduced the content even further, as shown in studies using clay to reduce the tannic acids of acorns.  However, as stated above, the researchers suggested that the acorns were eaten raw, with no evidence of leaching.

There’s another issue involved with the consumption of unprocessed acorns, that being the presence of excesssive phytic acid in the diet.  Phytic acid is the primary storage form of phosphorous in plants (including acorns), and when ingested, decreases the availability of certain minerals such as zinc, iron, calcium, and magnesium.  Some oaks contain as much as 2.67% phytic acid by weight, similar to linseed, pinto beans, and tofu (4).

Phytic acid, unless properly dealt with, may affect mineralization involved in enamel building (5).  If this population of hunter-gatherers took the necessary precautions of leaching and cooking the acorns (which they could have, but the evidence is lacking), the phytic and tannic acids would be minimized.  The researchers place most of the blame on acorns as the reason for rampant tooth decay, but perhaps the issue has more to do with the processing methods (raw/leached/cooked), and less to do with the species.

The researchers also revealed other possible explanations for the oral wear and tear experienced by these hunter-gatherers.  For example, land snails were part of their diet, and consumption of abrasive particles could have contributed to tooth wear.  This specific population was known to use stones to pound and grind their food, and abrasive particles from the stones may have led to further tooth wear.  The individuals may have also harbored virulent bacterial strains specific to dental decay that spread rapidly within the population.  Without adequate oral hygiene, this could have greatly influenced the prevalence of dental caries.

It’s difficult to know exactly what led to the high prevalence of tooth decay within this Moroccan hunter-gatherer population.  The NPR article focuses almost entirely on the consumption of acorns as the leading cause, however based on the evidence, only a correlation can be made (and even that is tenuous).

There is limited evidence to suggest that acorns, at least from the holm oak species, are cariogenic.  If they were, we might also find a higher prevalence of dental decay among indigenous groups that relied on acorns as dietary staples.  This isn’t the case, however, and instead we see acorn-eating populations throughout history who experienced great health.

Many more points could be addressed – for example, generalizing this particular diet of wild foods to all paleo diets.  However, no single paleo diet exists.  The real paleo diet of the past, which was a hunting and gathering wild food diet, varied greatly between different areas of the world, and was based on the biodiversity within particular ecosystems.  To say that the paleo diet wasn’t always conducive to good oral health, therefore, is inaccurate.  The North African hunter-gatherer diet of the Later Stone Age?  Maybe.  But not all.

Fear not, for the hunter-gatherer lifestyle has indeed been shown to be a bit more favorable for oral health, though this point was somehow left out of the NPR article.  The researchers from this study stated:

“Frequencies of carious lesions in archaeological populations range from 2.2–48.1% of teeth for agricultural populations, but only 0–14.3% for hunter-gatherers.”

I’ll keep eating my acorns, properly processed of course.  I hope you will too.

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Thank you!
Adam Haritan



The 10 most common medicinal plants used by Native Americans

ArtemisiatridentataIn the United States, it’s easier, now more than ever, to acquire calories.  What was once limited to wild pursuits has been tremendously simplified to the process of supermarket harvesting.  And because of this, humans now have a steady supply of calories at their fingertips.

What’s not so easy anymore is the acquisition of medicine.  At first this may sound confusing, as pharmaceutical drugs are readily available from a variety of outlets.  What I am referring to, however, is natural medicine.

The domestication of our food, from the wilderness to the farm, correlates with a decline in phytonutrient levels.  Plant phytonutrients, some of which are antioxidants and anti-microbial compounds, benefit not only the plant itself, but the consumer of the plant as well.  A modern diet of cultivated foods lacks the presence of these natural medicines, and because of this, the health of the standard bitter-deficient dieter suffers.

The conventional solution?  Prescription drugs.  After all, a medicine-deficient dieter has to make up for the loss somehow.  And just what are the most commonly prescribed drugs in America (1)?

  1. Hydrocodone/Acetaminophen
  2. Generic Zocor (simvastatin)
  3. Lisinopril (Prinivil/Zestril)
  4. Synthroid (levothyroxine sodium)
  5. Norvasc (amlodipine besylate)
  6. Prilosec (omeprazole)
  7. Azithromycin (Z-Pak/Zithromax)
  8. Amoxicillin
  9. Generic Glucophage (metformin)
  10. Hydrochlorothiazide

Seems like we have no shortage of individuals with pain, high cholesterol, hypertension, hypothyroidism, acid reflux, bacterial infections, and to top it all off, type 2 diabetes.

It also seems this is what one would expect when most of the medicine in our food is bred out, purified and patented by drug companies, and sold back to us alongside a deficient diet of domesticated food.

Life wasn’t always this way, however.  Native Americans were very aware of the synergy between plants and humans, and incorporated various plants into their lifestyles for not only calories, but for medicine as well.

Daniel E. Moerman, a Native American ethnobotanist, compiled a book examining the plants traditionally used by indigenous cultures in America*.  In a previous post, I discussed the plants, according to Moerman’s research, with the greatest number of uses in several categories, and here I will be presenting the 10 most utilized plants by Native Americans for medicinal purposes.  Among 2,582 species analyzed, this is the list of plants Moerman provides, along with the number of uses amongst different cultures.

  1. common yarrow (Achillea millefolium), 355
  2. calamus (Acorus calamus), 219
  3. big sagebrush (Artemisia tridentata), 166
  4. fernleaf biscuitroot (Lomatium dissectum), 139
  5. common chokecherry (Prunus virginiana), 132
  6. Louisiana sagewort (Artemisia ludoviciana), 128
  7. devil’s club (Oplopanax horridus), 128
  8. common juniper (Juniperus communis), 117
  9. Canadian mint (Mentha canadensis), 115
  10. stinging nettle (Urtica dioica), 114

Many of the plants in this list are native to North America.  Some, however, were introduced in either pre- or post-Columbian times.  Regardless, the Natives were able to utilize an extensive pharmacopoeia to treat a variety of ailments, and did so successfully.  This is a perfect example of using food as medicine, alongside medicine as food.

Today, a different picture is painted.  What was once common knowledge has been lost or almost entirely forgotten.  Not only do people experience sickness due to poor dietary choices, but the issue is exacerbated even more by the lack of expertise in natural treatment.  The outsourcing of our food is essentially leading to the outsourcing of our medicine, ultimately resulting in a sick population that cannot take care of itself.

Something needs to change, evidenced by the fact that 7 out of 10 Americans are taking at least one prescription drug, with more than half that number taking two (2).  I understand the use of medicine in emergency situations, but the reasons for most of today’s prescription sales are due to poor lifestyle habits.  I also understand that a single plant may not hold the cure for a disease.  Cinnamon may not cure diabetes.  Congestive heart failure may not resolve itself through the supplementation of hawthorn alone.  But when used in conjunction with proper diet and lifestyle practices, they may certainly help.

Plant medicine is not wishful thinking.  Plants have been a part of our diet since the beginning of our existence, and surely serve essential functions in keeping us well.  We do not get sick because we lack enough pharmaceutical drugs to keep us well.  We get sick because we lack plant medicine.

If you’re looking for a good place to start, the list above may help.  Reward your body by incorporating more wild plants into your diet.  You deserve it!

*Moerman, D. E. (2008) Native American Ethnobotany. London: Timber Press, Inc.

Wild berries and health, Part 3: Fat metabolism

SilverBuffaloberryWe have been exploring the phytonutrient actions of wild berries relating to human health in this 3-part series.  If you are just joining us, here are links to the previous posts:

Wild berries and health, Part 1: Diabetes

Wild berries and health, Part 2: Inflammation

In this third and final post, I will be showcasing the role of certain berries in regards to lipid metabolism and energy expenditure.  Just in case you forgot which wild berries the researchers in this study analyzed, here is the list again (1):

  • serviceberry (Amelanchier alnifolia)
  • highbush cranberry (Viburnum trilobum)
  • chokecherry (Prunus virginiana)
  • silver buffaloberry (Shepherdia argentea)

The human body derives most of its energy from carbohydrates and fats (lipids).  Lipid metabolism refers to the synthesis of fats, as well as the way the body converts fats into energy.  It is critical that these processes run effectively, but in certain conditions this is not the case.  In metabolic syndrome, for instance, fat metabolism is impaired, resulting in increased levels of circulating free fatty acids and fat accumulation.  It is normal for lipids to reside in the blood (especially after a meal), but when they do not get shunted to their proper destination (liver, brain, etc.), problems can arise.

In this study, the researchers analyzed how the berries influenced fat metabolism by measuring fatty acid oxidation, or the way fats are converted to energy.  They also measured mitochondrial number to determine the effect of berry samples on the energy status of cells.  Mitochondria are the areas within cells responsible for energy production, and in abnormal conditions like metabolic syndrome, the number and function of mitochondria are impaired.

The researchers discovered that extracts from highbush cranberry, chokecherry, and silver buffaloberry displayed notable activity for enhancing lipid metabolism, while serviceberry and chokecherry increased mitochondrial number.  The findings led the authors to conclude that the ability of the berry samples to modulate lipid metabolism and energy expenditure is consistent with improvements in metabolic syndrome.

Quite the exciting discovery!  Metabolic syndrome encompasses a host of risk factors, including high blood pressure, high blood sugar, high triglycerides, low HDL, and belly fat.  According to the CDC, approximately 34% of adults 20 years and older meet criteria for metabolic syndrome, with the likelihood increasing with age (2).  When there are foods associated with improvements in metabolic syndrome, it may be prudent to seek them out and incorporate them into your current diet.

Sure enough, there are plenty of foods associated with improvements in metabolic syndrome.  Service berry, highbush cranberry, chokecherry, and silver buffaloberry all have the ability to improve the health of those who consume them.  Although this has been suggested by this particular study, keep in mind that the scientific method is only one way to seek answers.

Wild berries have been consumed for millenia by the indigenous peoples of North America.  The illnesses discussed in this series result from the abandonment of traditional dietary habits in exchange for the highly refined and domesticated foods of modernization.  It is no surprise that we do not see the rates of degenerative diseases in Natives who follow their traditional diets anywhere near as high as the rates experienced by modern, civilized humans.

It is important, now more than ever, to implement a strategy reacquainting yourself with the wild foods growing in your ecosystem.  Research the distribution of these four berries, along with other edibles, and begin the sustainable practice of gathering them for your consumption.  Consider them your allies in protecting yourself against the insidious diseases of affluence, and discover for yourself what it means to relay the inherent health of the Earth into your body.

Wild berries and health, Part 2: Inflammation

chokecherryIn the previous post, I discussed the action of certain compounds in wild berries that may offer protection against diabetes.  But if the discussion stopped there, several other important roles involving phytonutrients would go unnoticed.  Not only do extracts from wild berries exhibit aldose reductase inhibition (blocking the conversion of excess glucose to sorbitol), they also display anti-inflammatory effects (1).  This is no surprise, as diabetes and inflammation are related, especially in the condition of obesity-associated insulin resistance (2).

Here is the list of the 4 berries that were analyzed in the study:

  • serviceberry (Amelanchier alnifolia)
  • highbush cranberry (Viburnum trilobum)
  • chokecherry (Prunus virginiana)
  • silver buffaloberry (Shepherdia argentea)

The researchers discovered that compounds in all 4 berries exhibited anti-inflammatory effects, specifically in reducing Interleukin-1 beta (IL-1β) and Cyclooxygenase-2 (COX-2) expression.  IL-1β is a cytokine produced endogenously as a regulator of the body’s inflammatory response.  It has been a target for type 2 diabetes (3) because of its association with the death of beta cells, whose job it is to store and release insulin.  IL-1β, in addition to its role in diabetes, is implicated in other processes involving pain, inflammation, and autoimmune conditions.  Chokecherry and silver buffaloberry demonstrated the strongest effects in reducing IL-1β.

COX-2 is an enzyme involved in inflammation and is a target for NSAIDS like aspirin and ibuprofen.  Normally the enzyme is unexpressed, but in the inflammation process it is activated.  Chokecherry and silver buffaloberry, in addition to reducing IL-1β, also reduced the expression of COX-2.

Not all inflammation is bad, however, as short-term acute inflammation is necessary for defense against toxins, injury, and stress.  Instead, it is chronic inflammation that never gets extinguished.  In this state, the body continuously produces inflammatory mediators which alter normal physiological functions.  Diabetes and obesity are both associated with chronic inflammation, and reducing inflammation may protect against diabetes even in the obese (4).  For this, a dietary strategy may indeed help.

As seen in this research, wild berries, in particular chokecherry and silver buffaloberry, contain plant chemicals that reduce the expression of certain inflammatory compounds.  Although not specifically analyzed, it’s hard to imagine that wild edible berries exhibit the same unpleasant side effects that NSAIDS may create (increased chance of heart attack, stroke, liver damage, kidney damage, headaches, etc.).

Remember, in addition to the scientific evidence, we also have extensive traditional usage of berries amongst numerous groups of people.  It is only within the last few centuries that these foods have fallen out of favor, and, not surprisingly, the health of the general population has declined.

Stay tuned for part 3 of this series, where we will look at wild berries and fat metabolism, and put it all together.

Wild berries and health, Part 1: Diabetes

serviceberryBerries are excellent fruits to add to your wild food diet.  They’re plentiful, they taste great, and they have been used extensively by Natives in their traditional diets.

But what exactly makes wild berries so nutritious?  Researchers wondered the same thing, and in 2008, a study was published in the Journal of Agricultural and Food Chemistry examining the phyto-composition of four traditionally-used berries in North America (1).  These berries were:

  • serviceberry (Amelanchier alnifolia)
  • highbush cranberry (Viburnum trilobum)
  • chokecherry (Prunus virginiana)
  • silver buffaloberry (Shepherdia argentea)

In this 3-part series, I will be discussing the actions of certain compounds analyzed by the researchers, as well as explaining the potential benefits they may confer to our health.

First up: protection against diabetes.

Diabetes mellitus is a group of diseases related to the way the body handles blood glucose.  In a hyperglycemic state (high blood sugar), the body tends to convert more glucose to a sugar alcohol known as sorbitol.  This is done through the enzyme aldose reductase, which, among other places, functions in the eye, kidney, and myelin sheath.  Normally, only a small amount of glucose is converted to sorbitol, but in a hyperglycemic state the conversion is increased.  Excess sorbitol in the body can result in vision problems, kidney problems, and nerve damage.  In short, extra aldose reductase activity is associated with diabetic complications.

Enter wild berries.

The researchers found that all four berries demonstrated the ability to inhibit aldose reductase, with serviceberries and highbush cranberries showing the most effect.  Inhibiting aldose reductase means producing less sorbitol, which could lead to fewer eye, kidney, and nerve complications associated with diabetes.  Furthermore, the berries also displayed the capacity to improve glucose uptake.

In addition to aldose reductase inhibition, berries, on average, contain less sugar than other fruits, with wild berries generally having even less than their cultivated counterparts.  This should also be kept in mind for individuals with diabetes.

It’s important to note that it hasn’t been proven that these berries decrease diabetic complications, but that certain compounds isolated from them may have the ability to do so.  Still, the Natives consumed these berries and no doubt reaped the rewards that the phytonutrients provided.

What can you do?  See which wild berries inhabit your ecosystem and harvest them in season.  I like to freeze and later add them to blended drinks throughout the autumn and winter months, thereby extending the benefits they provide.  Especially if you are dealing with any blood sugar issues, consuming wild berries in addition to practicing healthy lifestyle habits can support blood sugar regulation.

Next up in this series:  wild berries and inflammation.

Lessons from Zimbabwe

AmaranthushybridusCommunities all over the world utilize wild plants for many reasons.  Here in the United States, the foods have fallen out of favor for the majority of citizens and have been replaced by a diet composed primarily of domesticated staple crops like corn, wheat, and soy.  Even though the evidence is clear that on average, wild plants are more nutritious than their cultivated counterparts, this fact alone may not be enough to recruit the U.S. population.

But if not for the nutrition, why else would individuals adopt a lifestyle of eating “weeds?”  Perhaps  the answer lies amongst the residents of Shurugwi District, Zimbabwe, who supplement their tropical agricultural diet of cassava, maize, millet, sorghum, and wheat with wild plants they gather within their community (1) .  They don’t earn much money either, as most are unemployed and make less than $50 per month.  Foraging for them, it turns out, is not only a means for nutrition supplementation, but also for food access and security.

Take a close look at the nutrient levels of the 5 most common wild edibles consumed in Shurugwi District, Zimbabwe (click to enlarge).


Amaranthus hybridus, commonly known as smooth pigweed, is an excellent source of calcium, zinc, magnesium, and vitamin C (all above the DRI).  The ratio of nutrition to caloric density in all of the foods listed is quite high, meaning individuals are receiving high amounts of vitamins and minerals without consuming many calories (when combined with staple crops, like maize, caloric intake is increased).  This nutrition persists into the dry seasons, when periods of drought create food shortages.  Because the residents preserve the wild plants through different methods, they are able to provide a buffer against cold and dry spells when they occur.  The foraged food, therefore, plays two important roles in Shurugwi District: nutrition and food security.

In the United States, 46.5 million people, or 15% of the population, live in poverty.  Many inhabit food deserts and have access only to convenience stores and gas stations.  Efforts are being made to alleviate this problem, but very few focus on the massive potential that one solution contains.  What if there was a shift in focus to wild food identification and foraging, as well as preservation and storage?  As the inhabitants of Shurugwi District demonstrate, a strategy is necessary to ensure food access and security, not only involving the cultivation of crops through agriculture, but the sustainable harvest of wild edibles as well.

Yes, certain wild edibles alone may not meet the caloric needs of those who consume them.  But any effort to increase the consumption of these plants (and/or animals) is a huge step forward for every human being in the quest for sustainability, survival, and health.