Dr. Nick’s Reply To “Debunking The Paleo Diet | Christina Warinner | TEDxOU”

Dr. Nick’s Reply To “Debunking The Paleo Diet | Christina Warinner | TEDxOU”


thank you it’s a pleasure to be here I’m
an archaeological scientist, and I study the health and dietary histories of
ancient peoples using bone biochemistry and ancient DNA and I’m here today
because I want to talk to you about the Paleo diet it’s one of America’s
fastest-growing diet fads the main idea behind it is that the key to longevity
and optimal health is to abandon our modern agricultural diets which make us
ill and move far back in time to our Paleolithic ancestors more than ten
thousand years ago and eat like them now I’m really interested in this idea
because it purports to put archaeology in action to take information we know
about the past and use it in the present to help us today now this idea was was
really started in the 1970s with this book the Stone Age diet it’s diversified
since then into several variants including the Paleo diet the primal
blueprint the new evolution diet and meander thing and most of the the
language of these diets makes references to anthropology nutrition science and
evolutionary medicine the diet does seem primarily targeted at men so if you look
at advertisements and descriptions they have virile cavemen like images things
like live primal lots of red meat and that can basically be the idea behind it
can be broken down into four parts one is that our agricultural diets today
make us chronically ill that they are out of sync with our biology and to that
we need to abandon these agricultural diets that started during the
Agricultural period and move back in time to the Paleolithic and eat more
like our ancestors over ten thousand years ago third that we know what these
diets were like and what they were like was they had a lot of meat they were
mainly meat based and that that was supplemented with vegetables and fruits
and some nuts and oils but it definitely did not contain grains or legumes or
dairy okay so
what she’s saying is she summarized he’s saying that the the people purporting
the Paleo diet and the keto diet that they’re saying that the diet was mostly
meat but she’s going to go on to basically comment about that because
there are carbon dating x’ for the way to analyze feces and dr. van from Texas
University was able to discuss this topic and say that you know our
ancestors millions of years ago ate principally vegetables and fruit and
various things that grew like yams and potatoes and things so they they
definitely didn’t have dairy or much in the way of animal product per se but so
let’s let’s go on to hear what her concepts or theories are and for that if
we emulate this ancient diet it will improve our health and make us live
longer and so what I want to talk to you about today is that this this version of
the Paleo diet that promoted in popular books on TV on self-help websites and in
the overwhelming majority of press has no basis in archaeological reality so
thank you no I’m not gonna end there I will I will explain okay so what I want
to do as an archaeologist is go through this do a little bit of myth-busting of
some of these foundational archaeological concepts upon upon which
it’s based and I thought I want to talk to you about what we really do know from
the archaeological record and from scientific studies about what
Paleolithic people did eat so miss one is that humans are evolved eat meat and
that Paleolithic people’s consumed large quantities of meat humans have no known
anatomical physiological or genetic adaptations to meat consumption quite
the opposite we have many adaptations to plant consumption
take for example vitamin C now carnivores can make their own vitamin C
because vitamin C is found in plants if you don’t eat plants you need to be able
to make it yourself we can’t make it we have to consume it from plants
we have a longer digestive tract than carnivores that’s because our food needs
to stay in our bodies longer so we have more time to digest plant matter we need
more surface area we need more microbes we have generalist intuitions so we have
big molars that are they’re there to shred fibrous plant tissue we do not
have carnassial’s which are the specialized teeth that carnivores have
to shred meat and we do actually have some genetic mutations and some
populations that are adaptive to animal okay so it’s important to recognize
she’s saying that overall the human species is adapted to eat plants we have
a longer digestive tract to keep the foods and longer to digest it mixed in
with microbes we have the the teeth structured the dental structure that
allows us to chew and crunch on vegetables and various fruit and so
forth and we don’t have the sharp canine teeth and she’s going on further to talk
about maybe some adaptions we’re able to adapt but we’re not designed to eat
animal product on rugger basis let’s go further here because we’re all talking
about tips for longevity and well-being and we’re gonna get on to some
supplement and stem-cell and hormonal things as well well consumption but it’s
– milk not meat and these are rose and certain populations during agricultural
periods primarily in Europe and Africa the meat and I call this the meat myth
if the idea behind it is that we should eat all this red meat but that’s just
really not true if you look at this plate of meat here for example these are
from fatted cattle these are domestic animals anything a Paleolithic person
would have eaten would have probably been very lean probably small and they
wouldn’t really have eaten that much meat of course there’s also bone marrow
and organs these would have been very important we see evidence of harvesting
of bone marrow and faunal assemblages where you see characteristic cutting
open of the bones like you see here for marrow extraction now sure people did
eat meat and especially in the Arctic in areas where there’s long periods where
plants are not available they would have eaten a lot of meat but people that
lived in more temperate regions or tropical regions would have had a very
plant portion of their diet so where does this meat myth come from there’s
really two places and one is the inherent bias in the archaeological
record bone is 80% in mineral by weight it’s
going to preserve better and longer over thousands of years the delicate plant
remains but the other issue comes from some early bone biochemistry studies
that were performed on Neanderthals and early people this bone biochemistry
study is based on that something called nitrogen stable isotope analysis it’s
complicated but I’m gonna try and break it down the basic idea is that you are
what you eat and so we there’s nitrogen 15 and nitrogen 14 heavy heavy and light
versions of nitrogen and we consume this nitrogen in our food but was there’s one
important difference and that is with each step that you go up the trophic
hierarchy the amount of the heavier isotope increases so if you measure the
amount of heavy isotope in the bone you can infer where that individual was on a
food chain this is an example of a generalized isotopic model and I’ve
plotted where plants generally fall and then above them or the herbivores and
then above them the carnivores but one of the problems is is that not all
ecosystems conform to this model there’s a lot of regional variability so if you
don’t understand the region you can come to erroneous conclusions so I’m going to
give you some examples we can take east africa if we measure animals and humans
ancient humans in East Africa we see some very strange patterns first of all
how can a human be higher than a lion Lions only eat other animals and then
how is this herbivore above a lion well it turns out that the food that you eat
is not the only contributor to these isotopic values and that aridity can
also have an impact so what we’re likely seeing here is differences in water
access so let’s move out of the savanna and move into the tropical areas let’s
look at the ancient Maya again we see something anomalous we see the ancient
Maya lining up with Jaguars now we know the ancient Maya had diet heavily
reliant on corn so what’s happening we don’t exactly know but we think this
may have to do with the way they performed agriculture and how they
fertilize their crops now let’s go to the pleistocene we see some really
interesting patterns here too we see reindeer flooding very low in the range
of plants we see wolves plotting normally where you would see herbivores
and we see mammoths panning all three levels at once plants herbivores and
carnivores so what we think is happening here is that in very very cold climates
animals eat unusual things and in this case we think what is happening is these
mammoths are eating lichens and bark that’s giving them very strange values
so if we now go to humans ancient humans Paleolithic humans and Neanderthals we
see that they plot in the same isotopic space as Jaguar or as wolves and hyenas
now that’s true but as I’ve shown if you don’t have a good control over the
regional isotopic ecology you can come to an erroneous conclusion and I think
it’s premature to say this is very strong evidence of meat consumption
given how very little we really know about the Paleolithic ecosystems so myth
2 is that pale of the peoples did not eat whole grains or legumes now we have
stone tool evidence from at least 30,000 years ago that’s 20,000 years before the
invention of agriculture of people using stone tools that look like mortars and
pestles to grind up seeds and grain more recently we’ve been developing
techniques where we can actually measure this thing called dental calculus it’s
very interesting it’s fossilized dental plaque we can go into the individual
mouths of people pull out that plaque and recover micro fossils of plants and
other remains my team is working on developing methods to extract DNA and
proteins and other research groups are focusing on these micro fossils like
starch grains pollen and phytoliths now we’re still in early days here but
even with the limited research we have we can say that there is an abundance of
plant remains inside the dental calculus of Paleolithic people’s and these things
include grains including barley refining barley inside a Neanderthal teeth inside
the plaque we also have legumes and tubers
so myth three is that pale paleo diet foods in the in the diet fad diet or
what our Paleolithic ancestors ate that’s just not true
every single food that’s pictured in these advertisements are all
domesticated foods they’re all products of farming of Agriculture they’re from
the Neolithic transition so let’s give an example let’s take bananas bananas
are the ultimate farmers food they can’t even reproduce in the wild anymore we’ve
actually bred out their ability to make seeds so every banana you have ever
eaten as a genetic clone of every other banana grown from cuttings that they’re
definitely a farmer’s food if you were to eat a wild banana it is so full of
seeds that I bet many people in this room wouldn’t even recognize it as
edible let’s take salads that seems like a
really great Paleo diet food except that we’ve radically changed the ingredients
to suit our needs so wild lettuces contain a great deal of latex which is
indigestible and irritates our gastrointestinal system it’s bitter the
the leaves are tough we’ve domesticated them to be softer to press bigger leaves
to remove the latex in the bitterness remove the spines that naturally grow on
the leaves and stems of wild varieties to make them tastier for us the tomato
that’s shown here does it lacks the Tomatina and solanine toxins that are
present in its wild relatives which are all members of the poisonous nightshade
family if we look at oil it’s true that olive oil is the only natural vegetable
oil that can be harvested without synthetic chemicals except it still
requires at least rudimentary presses to remove it something that no Paleolithic
person would have ever built this is a farmer’s food this is a model diet I
found on the web okay that’s a really important statement that the ability to
express oils out of all of she says it’s the only thing the only food that made
sense to build pull oil out of but you’d have to have what’s called a
cold-pressed process which came out about 1900 to be able to extract oils
out it was never used in large scale the way we do
in the current American diet so I tend to agree that the the whole food
approach makes sense but it doesn’t make sense to add olive oil as a new recent
phenomena that isn’t really part of healthy living and eating so I think
that she’s bringing up a great point here and we need to pay attention
because the whole idea of longevity is eat and sexually unprocessed foods right
does that make sense to you so the more unprocessed foods that you eat the
better you’re going to do so let’s continue on
with her model she’s talking about some of the early vegetables that were quite
different than today’s high bred vegetables but it doesn’t mean we
shouldn’t eat more vegetables and more fruit we do need to eat them in a wide
variety slice it looks like a delicious and nutritious breakfast and I’m sure it
is but it’s not something a Paleolithic person would have had access to first of
all the blueberries are from New England the avocados are from Mexico and the
eggs are from China this would have never appeared on any Paleolithic plate unless we have this problem of size
domestic blueberries are twice the size of wild blueberries we’ve already talked
about bananas you look at avocados a wild avocado has maybe a couple
millimeters of fruit on it and the same goes for wild wild olives and of course
chickens chickens are prolific producers they’ll egg eggs almost every single day
they’re predictable large and abundant if you’re trying to collect wild eggs
they don’t lay your around and they’re not as easy to find they’re typically
small but maybe you’re not convinced so I’m gonna give just a couple more
examples so this you may all recognize as broccoli broccoli did not even exist
in the Paleolithic period what you see on the left is wild broccoli looks quite
different now while broccoli is also wild cabbage wild cauliflower wild kale
wild kohlrabi and wild Brussels sprouts they’re all the same species the only
difference is there are different cultivars we’ve selectively bred the
same species to produce the kind of food that we like best
these are human inventions broccoli I think is an interesting example because
it’s this weird thing what even is broccoli it’s such a strange-looking
vegetable so I think it’s important to recognize that she’s talking about the
some of the beliefs that certain vegetables weren’t really as prevalent
or present as they are today so we just again need to understand that hybrid or
changes in broccoli or bananas these things weren’t as starchy in those days
but it’s okay because starch breaks down slowly I’m gonna show you a video here
coming up about fructose but she talks also about the idea that sugar cane you
you would have to eat the equivalent of eight feet long of sugar cane to equal
like the amount in a soda pop so really keep it in mind
the American diet and of course the use of food preservatives and chemicals and
what’s going on with the microbiome all these things are very important and III
think it’s a good beginning to recognize that we as Americans eat too many
calories so here let’s jump into this part where she talks about the sugar
cane I think it’s it’s it’s a pretty good portrayal sugar cane do you think
do you think you’d have to eat I brought some sugar cane how many feet of sugar
sugar cane do you think you’d have to consume to reach that level any ideas
one how many sticks do you think you’d have to eat they’re pretty big not quite
40 feet you have to 8.5 feet of sugar cane to reach to reach that level that’s
an awful lot of sugar there is no physical way that a Paleolithic person
could have possibly eaten that much sugar cane even if they really really
wanted to and now you can consume it in about 20 minutes
so we’ve by decoupling the whole food from the nutrients inside of it we trick
our bodies and we can we can override the the mechanisms that we’ve evolved to
signal fullness and satiation and these are the three main
lessons I think we can learn from real pilots there’s no one correct diet but
dietary diversity is key that we need eat fresh foods when possible and that
we need to eat Whole Foods so anthropology and evolutionary medicine
have a lot to teach us about ourselves and new technologies are opening up new
windows into the past but we