State of play: diet and food
Throughout this Cancer Prevention Action Week, we are reviewing the current state of public policy for the major risk factors in causing preventable cancers.
There is a clear link between obesity and numerous cancers – 13, according to Cancer Research UK. This link is both statistically clear, and increasingly well understood in biomedical terms: fat cells do not simply sit in the body, but interact with its processes, particularly influencing growth and sex hormones and causing inflammation, all of which increases rates of cell division and therefore the risk of a cancer developing.
However, tackling obesity is a complex and sensitive topic. As we discussed in a previous article, the temptation to blame individuals for making poor choices is strong, but wrong-headed. The rise in obesity levels over recent decades has been overwhelmingly caused by changes in diet. The prevalence of obesity doubled from 1990 to 2020, following major structural changes to the food we buy and how we buy it. From the 1970s onwards, ready-made, “ultra-processed” foods high in salt, fat and sugar became more common in our diets: the UK has the highest consumption of these foods in Europe.
At the same time, supermarkets came to dominate food retail, spurred on by changes to planning laws that made large out-of-town shops feasible. Supermarkets achieved a dominance that enabled them to drive down prices for consumers, but also exert enormous influence over what is available for us to buy, and how attractive different products can seem.
Takeaway food options have also expanded enormously over recent decades, most commonly offer tasty but unhealthy meals, and are more common in economically deprived neighbourhoods.
The need for changes to diet and food supply
It is CancerWatch’s view that major structural changes are needed in order to reduce levels of preventable cancer. This must mean making changes to our food chain and distribution: while changing individual behaviours has its place in the mix, this sort of change is always easiest for people who are already relatively well-off and relatively advantaged. But that is not where change is most needed: the problems with our food supply are a key factor in health inequalities. Sir Michael Marmot’s second review of health inequalities identified the characteristics of an unhealthy high street: they include higher density of payday loan, alcohol, gambling and fast food outlets. And over a million people in the UK live in “food deserts”, meaning they lack access to cheap and nutritious food (in practice, this usually means access to a supermarket).
We therefore argue that this issue should be approached and framed in terms of food and diet, rather than obesity. There are several advantages to taking this approach. One is that it encompasses other food-related factors in causing cancer, such as processed and red meat, which are clearly established factors in causing bowel cancer, and heavily implicated in stomach and pancreatic cancer as well.
Even more importantly, discussion of healthy eating is more acceptable to public opinion. Obesity is still widely understood (or misunderstood) as a personal failing arising from individual choices, and many people are inclined to reject messaging suggesting that individual choice is not the main problem. However, people are generally more receptive to messages about healthy eating, or diet as a factor in improving their overall health, rather than focusing just on wider causes of obesity. Messages pointing out the role of health inequalities also tend to be better received when they relate to access to food, rather than to levels of obesity. This is therefore the route to achieving public buy-in for structural change (although entirely discounting the role of personal responsibility is understandably greeted with scepticism: people expect to continue to see it as part of the policy mix).
Cancer Research UK’s much-publicised advertising campaign in 2019, drawing attention to the link between obesity and cancer, therefore somewhat fell into the obvious trap. CRUK’s policy positioning on what is needed to reduce the incidence of preventable cancers by reducing obesity is entirely right, and it is true that the link between obesity and cancer is not as widely known as it needs to be. But their posters might have done better to call for a specific policy change to improve diets: without that, their messages were directed at an audience of individuals, which carried the implication (whether intentional or not) that it was for those individuals to do something about it, and nobody else.
Policy options, and action to date
So, what action could be taken, and how much is already on course to happen? The good news is that action can be taken on many fronts: there is no shortage of possibilities. Planning reforms could be deployed to address unhealthy high streets, for example, and food deserts could be targeted through a collaborative approach between supermarkets and government both locally and centrally. The power of supermarkets more broadly could be leveraged to good effect: they are being prohibited from heavily promoting unhealthy foods from October this year (albeit this measure is much delayed), but could potentially use their dominant market position to promote healthy choices more heavily.
Measures to prompt the reformulation of food and drink to be more healthy could also be developed. The Soft Drinks Industry Levy (better known as the sugar tax) led many manufacturers to reformulate their products, and has enjoyed widespread public support. More measures of this sort are surely viable.
Public Health England undertook much valuable policy development work in this area, prior to its abolition (for example this paper on calorie reduction and this on a whole system approach to obesity). Unfortunately the Government Food Strategy published last year falls well short of taking the bold structural action needed, including failing to adopt many of the recommendations of the independent National Food Strategy that it had previously commissioned. Until much stronger action is taken, the costs of our current food supply and dietary problems will continue to be passed on to the NHS, and many people will continue to develop preventable cancers.
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