Nutrition and Wellbeing Week 1: The Makings of a Healthy Diet Step 1.4: How diets have changed from the age of the cavemen to current day [MUSIC PLAYING] ALEX JOHNSTONE: Our diet as humans has changed over millions of years. We have evolved from Stone Age, or Palaeolithic Age, of 2 and 1/2 million years ago to now, what I call the Obese Age. This is as a result of the ready-to-eat food available 24 hours a day at relatively cheap cost, making it very easy to over-consume relative to our energy requirements. We can gain insight into how our diet has changed from archaeology, from burial sites, plant and bone remains, and vessels, utensils, and depictions, such as cave drawings. In this following section, we will briefly explore how nutrition has influenced the development of Homo sapiens. I met with Dr Karen Milek, lecturer in archaeology from the Department of Geosciences to find out more about this process. KAREN MILEK: I'm here with a selection of different hominin skulls, which we have in the collection at the Department of Archaeology here at the University of Aberdeen. And you can see that they're all really different. They have different brain sizes and shapes, different cranial capacities. They have different shapes to the face and also different shapes and sizes of teeth. And all of these evolutionary characteristics are related to past environments, past diets, social structures within all of these groups. So if I start with a modern human, this is the skull of a modern European female. And you can see that it has a very large cranial capacity compared to many of the other specimens here, especially a lot of cranial capacity in that frontal lobe. This is a female, and that frontal lobe is nearly vertical. You can also see that we are perfectly adapted to upright locomotion on the basis of this hole here, which is very centred on the skull. This is where the spine enters the skull. And as you'll see when we look at some of the other skulls, the location of this entry point of the spine changes according to the type of locomotion that our ancestors had, whether they were knuckle walkers or whether they were walking upright.

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So in comparison to the modern human, this is a modern female chimpanzee’s, which has a much smaller cranial capacity. While the modern human is around 1,400 cubic centimetres, a modern chimpanzee is around 300 cubic centimetres. And that there's almost no forehead at all, but very big brow ridges here. The teeth are really different, really large canines. And that's because of the kind of social life of chimps, as well as the diet. Their diet is very diverse. They're adapted to eating everything from nuts and insects and different kinds of vegetable matter and fruit all the way to eating meat. And they are hunters as well as being vegetation eaters. The location of that hole at the bottom of the skull is really far back. So if you can see, the entry point of the spine is heading towards the back of the skull. And that's because chimpanzees are knuckle walkers. They're used to leaning forward. And so they're adapted to a different kind of locomotion. One of our oldest ancestors is Australopithecus afarensis, who was living between two and three million years ago. The famous Lucy belonged to that species. Now, this species was essentially an upright walking ape. You can see that the cranial capacity is still really small, around 300 cubic centimetres. And the difference is that that hole where the spine enters the skull is really far forward again. And you can tell not only from this feature, but also the shapes of the bones in the rest of the body, the shapes of the hip and the knee, what the leg bones are like, that she was upright walking. This was the skull of a Neanderthal. And Neanderthals have really large brains, up to around 1,500 cubic centimetres. And what's really interesting about them is that the majority of that brain is at the back of the skull rather than in the forehead. Neanderthals also have an interesting pathology, which you can see in the teeth here. They're really worn down at the front of the mouth. And this is a frequently recurring feature of Neanderthal skulls, and it's probably related to the fact that they're using their front teeth in different ways from modern humans, either in their diet or the fact that they're working some kind of sinew or leather, or that they're using those front teeth as a kind of grip. This is an example of Homo heidelbergensis. This is our direct ancestor of both Neanderthals and modern humans. And heidelbergensis has very large brain, again, mainly at the back of the skull. Heidelbergensis was a species present in

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both Europe and Africa. In Europe, it evolved into Neanderthals, and in Africa it evolved into modern humans. This bizarre looking fellow is the skull of Australopithecus boisei, nicknamed Nutcracker Man. And as you can see, it looks really different from some of the other specimens. And that's because this species evolved with very distinctive characteristics, probably related to a very specialised diet. And it has really large jaw bones, and this is probably related to very large muscles that were wrapped around the side of the head and indicate that this species was probably highly specialised at chewing tough foods like nuts, roots, things like that. ALEX JOHNSTONE: The theory of evolution says that a change in diet which boosted to a nutrient rich diet led to enhanced brain growth, which enabled acquisition of skills such as toolmaking, language, and cultural expression. Modern man is genetically Stone Age, and we still consume some foods that were available in this Palaeolithic period. We can look to historical data to tell us how our food intake and nutrition has evolved over time. Cookbooks, courtly literature, religious texts, published chronicles, household and hospital accounts and medical texts all provide us with insight into how our diets changed in the past. The change in global weather conditions and traditional hunter-gatherer lifestyle has resulted in a shift from foraging to agricultural diets. Major shifts in food choice and nutrient intakes occurred around the Industrial Revolution and changed farming practices around cereal production. In the 21st century, mass produced ready-to-eat meals and processed foods have emerged alongside globalisation and large-scale farming practices. What can we learn about eating from our ancestors? We know that life expectancy for hunter-gatherer ancestors was lower than it is today. However, studies of contemporary diets rich in palaeolithic foods, including lean red meat, seafood, fibrous foods have revealed significant and positive changes to markers of disease. This has led to renewed trends to incorporate this way of eating in our modern diet. These diets, however, are difficult to stick to because of the low grain and cereal content. They are also contrary to current healthy eating advice. And we will consider some of the purported advantages and disadvantages of palaeolithic style of eating later in the course. Over millions of years from primate to modern human, our diet has evolved as an omnivore. Modern diets in the developed world have contributed to the development of obesity and related noncommunicable diseases, such as

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cardiovascular disease and diabetes. Scientists argue that the discordance between our ancient and genetically determined biology and our current nutritional, cultural, and activity patterns of contemporary western populations result in the emergence of the so-called diseases of civilisation. [MUSIC PLAYING]

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