The last two days I attended this year’s ‘Science and Society Conference’ an annual conference series which –this time- was focused on “Foods are us! On becoming and eating”. I had a great time and really enjoyed many interesting presentations by food science experts from very diverse disciplines and backgrounds. This ranged from chemistry and molecular biology to psychology and sociology.
The meeting started with a great talk by Mark Thomas presenting the current picture of the evolution of human diet over the last 3 million years. This can be seen as a series of food related revolutions that had an incredibly drastic impact on human nutrition, behavior and human development in general. With first (stone) tools hunting became more efficiently which shifted diets to a higher (meat-based) protein uptake. Importantly, this also represents a higher energy intake so that humans could effort to spend more time not hunting and gathering. In addition higher energy levels ultimately made it possible to develop bigger brains which is quite costly (about 20-25% of our energy expenses)1. Later radical changes came from the invention of cooking which again led to more energy efficient nutrition since cooking reduced the energy cost for digestion. And finally one of the biggest revolutions arguably was farming. Interesting enough, according to Mark Thomas “we are still suffering from that”. Farming was only invented about 10000 years ago which might sound much but is practically nothing in terms of human evolution. So what Mark Thomas is saying is that we still haven’t completely adapted.
So better go back to pre-farming nutrition, right? Yeah, finally some scientific backup for the ‘paleo diet’? Of course: not.
Even if Mark Thomas is right with his hypothesis that we still haven’t fully adapted to farming, he can also only warn (or make fun) of paleo diet crap. First, nobody even knows what paleolithic people ate. And second, we do have adapted to farmed food quite a bit2. One of the most striking examples of human adaptation -and the area of expertise of Mark Thomas- is the evolution of lactose tolerance in grown-up humans. It started at several places on earth wherever milkable animals were kept (e.g. Nigeria, Sudan, Middle East, India, and Europe) and must have been a major evolutionary benefit since it spread extremely fast so that in regions like north-west Europe practically everyone tolerates milk consumption as a grown up.
Panel discussion with the first day speakers at the Science and Society Conference. From left to right: Mark Thomas (University College London, UK), Jim Kaput (Nestlé, Switzerland), José Ordovás (Tufts University, USA), Charles Spence (University of Oxford, UK), Priscilla Parkhurst Ferguson (Columbia Universtiy, USA), Paolo Gasparini (University of Trieste, Italy), Erin Schuman (MPI for brain research).
Jim Kaput from Nestlé raised awareness for the influence of the genotype (different people = different genes) on the effect different foods can have on different people. Depending on the type of question you asked, such has ‘what effect will a high-fat diet have?’, people apparently can be classified into different ‘types’ al standing for varying responses. Interestingly, the fractions of these different types then depend notably on genotype for instance in between different ethnics. In a following talk, José Ordovás further elaborated on correlations of the effects of specific diets and genotype. Paolo Gasparini then looked more into how flavor perception and thus in the end preference for different diets depends on the genome.
Interesting to me, and very comforting, was the fact that Jim Kaput confirmed that the food that we eat is more important than the genotype3. Later in the conference, when Simon Carding introduced the microbiota it again became apparent how little the genome actually determines our ‘fate’, food-wise I mean. After all, our diets, our habits including things like exercise, or our gut bacteria seem to have a far greater effect on our health and our response to food!
A bit along the same line, Hannelore Daniel pointed out that everyone of us has a unique metabolism which in addition is highly dynamic and changes with changing habits. So, again, most things about food and health seem to be ‘plastic’ as scientists like to say. Adaptable you could say. Our genome is only a vague starting point for development of our selves throughout our lifes.
Other very interesting contributions came from Charles Spence which is well-known even in popular media for his psychological food perception experiments. His lab demonstrated many fascinating things, often in close collaboration with chefs. For instance, that round chocolate tastes sweeter than squares, or that a dessert is perceived differently when eaten from either a black or a white plate. In general, it’s all about the multi-sensory aspect of food perception.
Priscilla Parkhurst Fergusson and Hannah Landecker further presented their sociological and historical perspective on food and food science which was a nice contrast to the mostly natural science dominated line-up.
And what about some nutrional recommendations? In spite of the enormeous complexity of humans, of food and of the interplay between humans and food it still came pretty much down to Michael Pollan‘s often cited statement: “Eat food. Not too much. Mostly plants.”Footnotes
- Another interesting point raised here was, that the bigger brain obviously was accompanied by bigger skull sizes which increased female deaths during birth. Brain growth after birth is a slow process, so that humans become reproductive fairly late. [↩]
- However, Mark Thomas also pointed out that the partial not-adaptedness to modern diets could explain some of our food-related behavior such as the (too) high hunger for high caloric foods [↩]
- This was also brought up by others, such as Michael Müller (Norwich). [↩]