How concerned should we be about ultra-processed food? And if you wanted to cut it out of your diet, following a slew of worrying studies on it, how simple would that be?

Not remotely simple, apparently. I wanted a loaf that was made of stuff I recognised, so I took a wander down my local supermarket’s bread aisle.

After checking around a dozen labels, I’d still drawn a blank.

The most straightforward definition of ultra-processed food (UPF) is food that contains ingredients you wouldn’t find at home, things like stabilisers, preservatives, emulsifiers, artificial flavourings, sweeteners and colourings. UPF is industrially produced and made substantially from substances derived from foods, and additives, rather than unprocessed ingredients in their natural state.

In the end, I found only one product that was made entirely with recognisable ingredients, some wholemeal flatbreads. An organic wholemeal loaf came second, containing added wheat gluten and ascorbic acid (vitamin C).

Both were definitely posh breads and significantly more expensive by weight than the average loaf.

How did it come to this, that you can’t just pop into a supermarket and buy affordable bread made of flour, yeast, water and salt?

Processing enhances the look, flavour, texture and lifespan of foods and some types of food are more likely to be ultra-processed than others. Ready meals, snacks and confectionery, mass produced bread, biscuits, processed meats and some meat substitutes are often, though not always, highly processed.

We all eat it. One estimate has it that 50 per cent of the calories we eat in the UK come from foods that would be classed as ultra-processed. Even if your diet is rich in fruit and vegetables, the chances are it’s also rich in reconstituted textured soya, methyl cellulose, soya protein concentrate, sodium nitrite, sodium alginate, invert sugar syrup and humectant. You’ll be eating foods that, apparently, have been hydrogenated, hydrolysed or subjected to fractionation.

No, I haven’t a scooby either.

But does it actually matter? It’s long been assumed that no, it doesn’t. Every food additive is tested to ensure it’s safe for human consumption, so it must be fine, right?

Read more Rebecca McQuillan: The referendum-that-never-was has left space for real politics

Read more Rebecca McQuillan: Should we be wearing Covid masks again?

I’ve always thought so. Years ago, back in the 1990s, enthusiasts for organic food would warn against the consumption of processed food on the precautionary principle, because “you never know”. They tended to embrace organic food as part of a wider lifestyle and philosophy that equated natural with good and man-made with bad, which could in itself be harmful if taken to the extreme. It was unconvincing.

But then reports started emerging suggesting a link between processed meats and conditions like heart disease and some types of cancer. Some scientists believed that this was due to higher salt, sugar and fat levels in processed meats, but others speculated that there could be more to it and that there was also something about the processing that was a problem.

Come 2023, and this debate is becoming impossible to ignore. Last month, two big studies were presented to the European Society of Cardiology that added to concern over UPF.

The first, tracking 10,000 women for 15 years, found that those with the highest proportion of UPF in their diets were 39 per cent more likely to develop high blood pressure than those with the lowest.

Importantly, this was the case even after results had been adjusted to take account of the amount of salt, fat and sugar the participants were eating, suggesting the processing itself could be harmful.

The second, an analysis of 10 studies involving 325,000 people, found those with the highest levels of UPF in their diets were 24 per cent more likely to have heart attacks, strokes and angina.

As these were observational studies, this doesn’t necessarily mean there’s a causal link between the processing of food and ill-health, though further research may unearth one. What it does mean is that thinking it’s a good idea to cut back on highly processed foods is no longer precautionary but based on evidence.

So should we all be going through our store cupboards and freezers, jettisoning anything with gobbledegook in the ingredients list?

Dieticians, including the UK Scientific Advisory Committee on Nutrition, are concerned. But given the limitations of the evidence, they don’t think we need to go cold turkey just yet.

Long-standing healthy eating messages already support reducing foods high in fat, salt and sugars, which are often highly processed, and eating more wholegrains, fruit, vegetables and pulses, which typically aren’t.

And because we don’t understand exactly why eating a lot of UPF is associated with poorer health outcomes, dieticians are wary of giving consumers the impression that all UPF should be avoided.

The NOVA system of food classification, which describes ultra-processed food, gives it a very broad definition indeed. Foods that are high in fat, salt and sugar are classed together with products that are low in those things.

The British Nutrition Foundation (BNF) points out that alongside things like some biscuits, sweets and fried snacks “the definition of UPF can also include foods such as sliced wholemeal bread and lower sugar wholegrain breakfast cereals which can contribute to an affordable, healthy, balanced diet”.

The issue of affordability is glaring. Anyone buying artisanal bread for a year will be spending the cost of a family holiday.

But the BNF is not dismissive of the evidence. It suggests that further research into the mechanisms linking UPF and adverse health is needed.

Above all, dieticians and health campaigners want the way foods are formulated and marketed to improve, so we can all be helped to make healthier choices. An important step would be to tackle promotions of high salt, fat and sugar foods – much of which will be highly processed.

The lesson of the supermarket bread aisle is that consumers can’t begin to deal with this on their own. It’s too confusing, the choice is too limited and people’s budgets and time are too constrained. Further evidence may emerge showing that processing itself is contributing to ill-health – perhaps, as some speculate, by compromising gut health.

Either way, consumers need a food environment that promotes healthier choices. It’s up to government and industry to make it happen.