In Search Of The Perfect Human Diet - Part II

Transcript From The Video - Part II

P rof. Mike Richards - Head of Archaeological Science Group
Dept of Human Evolution, Max Planck Institute for Evolutionary Anthropology

Prof. Richards is an Evolutionary Anthropologist. He and his team carry out stable isotope analysis of bone collagen to determine human and animal diets and show any dietary changes.

Mike Richards:
I run a group in a field called Archaeological Science. We specialise in applying hard science techniques to anthropology and archaeology.

Human diets are things that people are completely confused about. I certainly was growing up. You think its good to have a glass of milk, its good for you and to have lots of cereals everyday. These kinda things, but if you think about it, you realise that these diets are not so good for you at all.

I work with early human diets. My main speciality is diet. I study bone chemistry as a way of getting at what the diets of people and animals were in the past.

And one of the main things we're looking at is the evolution of diets through time. By trying to get this information from these bones themselves and doing scientific analysis of the composition of these bones.

People have hypothesised that its the first trait of homo, our species is that its animal products what led to our increased brain size. And all the sorts of things that set us apart from other primates.

And the problem is you can, the evidence for this is circumstantial

You find tools that are being used to cut up animals. you find butchered animal bones. But there's no way to really tell what proportion of the diet that represented. And plant foods just don't survive, so they're invisible.

So we have to use this kind of study to directly look at at the fossils themselves, with the bone chemistry. To really prove what proportion of their diet was coming from animal protein versus plant protein.

The first step is taking the sample, that usually happens in a museum or in the field. We try to take as small a sample as possible. so maybe like the size of a thumb nail we can work with.

We get that sample back to the lab, clean off the outside layer to get rid of any sorts of contaminants from the soil. Then we take that bone and we put it in hydrochloric acid and that dissolves away most of the bone.

Because most of the bone is mineral. That's where most of these contaminations from the soil will come in. So we want to get rid of that entirely and this leaves this protein. Then take that freeze dried collagen. White fluffy collagen to the mass spectrometer.

We measure the amount of carbon and nitrogen in it, again to make sure its really collagen. and then we measure the isotope ratios. When we get those numbers we compare for example Neanderthals to animals that lived at the same time. So you know if you have reindeer, you know they were herbivores. And if you have wolves you have carnivores. So you build up this whole food web with isotope values. You see how they all fit in.

When we pick up the story with the Neanderthals, which is the first time we can, we do see really they are getting all their protein from animal sources. So as predicted we pick that up. And as we see with modern humans as well, the same thing that they're very successful because they're eating mostly animal proteins as well, and very little plant foods in Europe, but a larger range of animal foods including I think fish, was a big part of modern humans.

So that was the idea we have of the sort of Paleolithic diet. We see with modern humans a lot of animal proteins.

I spent a lot of time working on neolithic and post-neolithic sites as well and there you really do see the humans with much lower nitrogen isotope values and they're clearly getting their protein from plants.

As agriculture moves in yeah. Before that they had the same values as the Neanderthals. Except for the addition of the addition of fish. That seems to be the biggest difference.

So until agriculture, were there any human, modern human vegetarians?

I really don't think so. I do not think so. Actually its extremely hard to find vegetarians even ethnographically, archaeologically. In all the studies we've measured thousands and thousands of humans from all over the world. And we've yet to find a vegetarian or a vegan. There's no way.

Sometimes we do, then we go back and realise we sampled a cow or something by mistake. Yeah, there are no vegans until recently.

When you get really big villages, people crowding together, and having a really high cereal, amount of cereals in their diet, you really see a difference in their bones.

Its these diseases you would never see, you never saw in the Paleolithic, we start to see in high abundance.

Does it make scientific sense as well as logical sense that we can learn things from their lifestyle that would then apply to us?

I think so. If you think of this evolutionary trajectory that made, how these humans evolved to this state, modern humans. We got to be this way and its over maybe a hundred thousand years of evolution to get to be this state.

Of actually adapting to this diet. Hunter / gatherer moving around a lot. Eating these wild foods. I think there's no question for most of the time that we've been around, we had a really, kind of nomadic lifestyle with lots of exercise and eating a lot of animal proteins and wild plant foods.

If you think of what's been successful in terms of us as a species, we've survived, ya know, 100,000 years, and most of that, 95% of that ,was this kind of adaptation. Eating these animal, wild animal foods. Plant foods with lots of exercise. That's what we've been very successful at.

Its a new experiment now, the neolithic, its a very short period of time, since we've been around, less than 10% maybe that modern humans have been around, so... I dunno, maybe its, you know.

If you think of it that way, what we are adapted to is not what we are living right now.

This kinda Paleolithic diet, I guess is probably the most optimal for modern humans. It has to be, its what you know, evolutionary pressure got us towards and we were successful with that kind of diet. I think it is.

Its gotta be the best diet for humans.

You have to go back to what we were most successfully adapted to up to this point, so I think the processed, the refined sugars, if we get rid of those. I think you have to have more exercise, it has to be built in. I mean Paleolithic humans were moving around all the time and got a lot of exercise.

I think meat eating is important, and processing food like cooking meat, and all those kind of things. Its the big things, that separates us a primate from the other primates.