“To eat is to compete in an arms race,” says Dr Chris van Tulleken, whose thoughts on evangelising through science, engaging food producers and self-experimentation promise another absorbing series of Royal Institution Christmas Lectures.
Can you summarise the central themes of your Royal Institution Christmas Lectures and what you hope your young audience will derive from them?
When the Christmas Lectures are broadcast on BBC Four and iPlayer in late December, we'll be taking an audience of (I hope) millions through the science of what happens inside our bodies when we eat. How exactly do we (and other living things) work out what to eat, and how do we turn that food into thoughts and actions?
We’re working from tastebuds to toilet. We’ll look at how what we eat has a massive effect on both our bodies and our brains, and how food has fundamentally shaped human evolution as a result. We’ll also be uncovering the importance of our microbiome – as the extra ‘organ’ we didn’t know we had – and asking how we can all eat better in future.
They’re going to be an amazing series of Lectures and at the end I hope we’ll have given our audience an entertaining insight into what we know and how we figured it out; that they’ll have maybe learnt something fascinating that they didn’t know before; and that they’ll maybe see science in a different way – as something that can be accessible and is for them. Most importantly I hope we’ll have given some – pardon the pun – food for thought about our diets today.
We are going to be covering the fact that, globally, poor diet has overtaken smoking as the leading cause of premature death, but it’s not about food-shaming or patronising, it’s about giving young people information that will be empowering.
How do you convey complex science to lay people without over-simplification?
The Lectures are enjoyed by scientists and a lay audience, including young people, and there are few institutions with more experience of conveying complex ideas to young people than the Ri. For my part I have been broadcasting about science and medicine to kids and young people for well over a decade.
My experience is that from a surprisingly early age (around eight) children are more than capable of understanding complex ideas – you only have to sit in the Ri Theatre for one of their regular public talks and hear some of the questions children ask to appreciate that – and in recent years the Christmas Lectures have asked young people to consider some pretty challenging societal and ethical questions around scientific advances.
So we’ll be doing the same. We’ll be thinking about it very carefully as we develop the scripts, because as I say, young people don’t need or want to be patronised. And we will definitely be using a lot of the Ri’s trademark demonstrations. There’s a reason why Humphry Davy was such a showman when speaking at the Ri – it’s because demonstrations are engaging, and they make complex science accessible.
Your work has highlighted the health impact of ultra-processed foods – do we need to be better aware of how that impact varies within categories of UPFs?
The evidence tells us that a dietary pattern high in UPF is harmful but it’s very clear that not all UPF is equal – and no one serious is proposing blanket approaches to all UPF. But one of the many big questions is how any UPF could be considered healthy – early analyses indicate that almost all of it is high in fat, salt, sugar and/or calories as well as having other harmful properties. So, whilst there is a spectrum of UPF, it’s hard to find many products that should be recommended. What is also clear is that there are many products which don’t meet the UPF definition, but which are also harmful. So, when it comes to policy we need to consider many aspects of food for regulating it and limiting the harms of our current food environment.
In your Lectures you’ll be looking at the impact of our modern diets on our own health and the planets. How do we fix our diet for the benefit of both?
There are two questions – what policies might an individual advocate for, and what might any one of us do ourselves. In terms of an individual diet, evidence is clear that for those that can afford and access it, a diet based mainly on plants, comprising mostly minimally processed and whole foods, is strongly associated with good human health.
It’s easy to propose that switching to local food, produced with minimal agrichemical inputs and packaging, would be good; but what we consume is largely determined by price, marketing and availability. This type of food is expensive to buy and prepare, so we need to find a way to overcome that fact that, for many people, the food consumed is determined by financial necessity.
There’s a reason why Humphry Davy was such a showman when speaking at the Ri – it’s because demonstrations are engaging, and they make complex science accessible
And the Ultra Processed Food system is not just harmful to human health – it’s the second leading cause of carbon emissions and greenhouse gases, and the leading cause of loss of biodiversity and plastic pollution. UPF is cheap when we buy it but very, very expensive later on.
For planetary health we need to reimagine the food system and that must start with demand – I’m not suggesting a food system designed from the top down that forces everyone to buy particular foods. Rather, I want to expose the workings of the food system and hope that will change both the demand for UPF and the way we regulate the system. The line detail on regulation is complex but we should start with warning labels and carefully considered taxes.
My seven-year-old can go into any shop and buy products which are indisputably harmful and there is no warning on any of them. There is no warning on a cola that it will destroy teeth. Surely we could begin with that?
Can you give us an insight into how the food we eat, and our need for energy, has shaped almost every aspect of human biology and physiology?
To eat is to compete in an arms race that has lasted billions of years and we’ll look at this in the Christmas Lectures. The world around us has a relatively fixed amount of available energy, and all life is engaged in a competition against other forms of life for that energy. Life has, after all, only two projects: reproduction and extracting energy to fuel that reproduction. Our senses of taste and smell, our immune system, our manual dexterity, our tooth and jaw anatomy, our eyesight: it’s hard to think of any aspect of human biology, physiology or culture that isn’t primarily shaped by our historic need for energy. Over billions of years our bodies have superbly adapted to using a wide range of food. Processing is a very important part of that. Humans have short guts, small teeth and small jaws because we process our food by cutting, grinding, cooking it and so on.
You’ve experimented yourself with UPF diets; to what degree is this a matter of scientific enquiry and to what degree is it about the communication of science to others?
I don’t want to give too much away but it’s fair to say if there’s any human experimentation on the Lectures it’ll either be on me, or someone very similar to me! I try to join up my research, my work as a doctor and my broadcasting. TV is a great motivator to begin an experiment. The UPF diet I went on was a great way of communicating about UPF, but it was also vital to collect data that helped my research group design an experiment which is now ongoing.
What two policy or educational interventions could most feasibly be implemented to counter the worst effects of UPF consumption?
No one thing will do very much. We learned this with smoking. Warning labels, plus engagement and education, plus tax, plus marketing restrictions, plus public health campaigns, and so on.
If I had to pick just two, I’d say investing in supporting parents during the first 1,000 days of life starting at conception is probably the most important thing we can do for children.
Then supporting schools to have kitchens that cook real food and to help them ensure that only milk and water can be drunk on school premises.
‘Bad’ foods can of course be highly addictive. What are the biochemical and psychological factors that prompt cravings in some people but not others?
There are social and genetic vulnerabilities which make addictions very hard to study, but what’s clear is that many addictions have similar sets of risk factors.
And that for many addictive substances there are many people (typically 80-90%) that can try the substance without developing problems. This is the case for alcohol, cocaine, tobacco and hyperpalatable/UPF food.
What is very clear is that we can create environments which really help those who may be vulnerable to addictions – fewer people struggle with tobacco addiction (and subsequent directly attributable impacts on their health) than previously because we changed the smoking environment. We have a long way to go with food and alcohol.
What areas of food science and which institutions and technologies are doing work that excites you? (and why?)
Much of my work is straightforward nutrition research but some forms part of a growing field called ‘Commercial Determinants of Health’, which is focused on how large corporations affect human health in good ways and bad ways. It brings together epidemiology, bench research, economics and the social sciences and it’s incredibly exciting as it offers some hope for solving some of the really big problems in the world. What’s exciting is the work coming out of research groups in the Global South like the nutrition team in Brazil at University of São Paulo who work with a range of other actors to create impact.
It’s hard to think of any aspect of human biology, physiology or culture that isn’t primarily shaped by our historic need for energy
One of the things that is very obvious from this research is that it is very hard for institutions that profit from products or activities causing problems to fund solutions. So I work with WHO, UNICEF and First Steps Nutrition who consistently show that they understand the problem and frame it correctly, with absolute clarity about how they engage with commercial actors.
Similarly the British Medical Journal has shown great leadership in managing conflicts of interest. The Food Foundation is also independent of Industry funding.
Is the food science research being done within different disciplinary fields becoming more integrated?
It is, but not as much as it should be. The sensory research about taste and flavour is really important because it may help explain why we eat more than we used to – but much of it is funded by the industry that is contributing to the health crisis.
Do the likes of yourself and the late Michael Mosley illustrate that, in science if not politics, populist approaches can play a valuable public role?
Populism is such a specific political term these days, and suggests a cynical approach to generating popularity, that I wouldn’t use it about science communication. Whereas what I think Michael did brilliantly was to hook people into some great science by creating a narrative that involved them and their families and by involving himself as the subject. He was a brilliant communicator (and a friend); one of the most important broadcasters of the last few decades. He understood how to get and keep his audience’s attention.
I think that there are many ways of communicating to the public about science. Some people want postgraduate science information and there is a growing demand for detail and critique of that detail. I think that’s in no small part due to the Ri engaging public audiences with science over many decades.
But whilst some people want to understand data in detail, almost all science communication needs to find a wrapping for information that makes it salient to the audience – we need to earn their trust and then entertain them whilst we inform and ideally involve them. One of the most important things, especially with younger people, is that they see people like themselves being involved in science. That may be based on race or sex or any other characteristic that make up our identities, including personality or delivery style.
Those of us who work within science know it is the most extraordinarily diverse, collaborative international environment and I think communicating that to young people considering their careers is really, really important.
- Dr Chris van Tulleken will give the 2024 Christmas Lectures from the Royal Institution, to be broadcast on BBC Four and iPlayer in late December
