While this newly published research and associated editorial are unlikely to end the wrangling about how best to define unhealthy foods and diets, it’s critical that such debates don’t delay the implementation of policies to actually improve our diets.
Bread, especially if it's wholegrain, is a big contributor to fibre intake. So it would be problematic to recommend avoiding supermarket wholegrain bread just because it’s ultra-processed. Photo / 123rf
Ultra-processed foods are industrially produced using a variety of processing techniques. They typically include ingredients that can’t be found in a home kitchen, such as preservatives, emulsifiers, sweeteners and/or artificial colours.
Common examples of ultra-processed foods include packaged chips, flavoured yoghurts, soft drinks, sausages and mass-produced, packaged wholegrain bread.
In many countries, ultra-processed foods make up a large proportion of what people eat. A recent study estimated they make up an average 42 per cent of total energy intake in Australia.
Ultra-processed foods are typically high in energy, added sugars, salt and/or unhealthy fats. These have long been recognised as risk factors for a range of diseases.
It has also been suggested that structural changes to ultra-processed foods as part of the manufacturing process may lead you to eat more than you should. Potential explanations are that, because of the way they’re made, the foods are quicker to eat and more palatable.
It’s also possible certain food additives may impair normal body functions, such as the way our cells reproduce.
High consumption of ultra-processed food has been associated with a higher risk of death from heart disease and stroke. Photo / 123rf
Is it harmful? It depends on the food’s nutrients
The new paper used 30 years of data from two large US cohort studies to evaluate the relationship between ultra-processed food consumption and long-term health. It tried to disentangle the effects of the manufacturing process from the nutrient profile of foods.
The study found a small increase in the risk of early death with higher ultra-processed food consumption.
But importantly, the authors also looked at diet quality. They found that, for people who had high-quality diets (high in fruit, vegetables and wholegrains, as well as healthy fats, and low in sugary drinks, salt and red and processed meat), there was no clear association between the amount of ultra-processed food they ate and risk of premature death.
This suggests overall diet quality has a stronger influence on long-term health than ultra-processed food consumption.
When the researchers analysed ultra-processed foods by sub-category, mass-produced wholegrain products, such as supermarket breads and breakfast cereals, were not associated with poorer health.
This finding matches another recent study that suggests ultra-processed wholegrain foods are not a driver of poor health.
The authors concluded that, while there was some support for limiting consumption of certain types of ultra-processed food for long-term health, not all ultra-processed food products should be universally restricted.
Evidence about ultra-processed foods suggests soft drinks, as well as alcohol and processed meats, are bad for our health.
Should dietary guidelines advise against ultra-processed foods?
Existing dietary guidelines have been developed and refined based on decades of nutrition evidence.
Much of the recent evidence related to ultra-processed foods tells us what we already knew: that products like soft drinks, alcohol and processed meats are bad for health.
Dietary guidelines already advise to eat mostly whole foods and to limit consumption of highly processed foods that are high in refined grains, saturated fat, sugar and salt.
But some nutrition researchers have called for the guidelines to be amended to recommend avoiding ultra-processed foods.
Based on the available evidence, it would be difficult to justify adding such a sweeping statement.
Advice to avoid all ultra-processed foods could adversely affect people on low incomes as many ultra-processed foods, such as supermarket breads, are relatively affordable and convenient.
Wholegrain breads also provide important nutrients, such as fibre. In many countries, bread is the biggest contributor to fibre intake. So it would be problematic to recommend avoiding supermarket wholegrain bread just because it’s ultra-processed.
Veganism has seen a significant rise in popularity in the UK, with an estimated 2.5 million vegans, representing 4.7 per cent of the adult population. Photo / 123rf
So how can we improve our diets?
There is strong consensus on the need to implement evidence-based policies to improve population diets. This includes legislation to restrict children’s exposure to the marketing of unhealthy foods and brands, mandatory Health Star Rating nutrition labelling and taxes on sugary drinks.
These policies are underpinned by well-established systems for classifying the healthiness of foods. If new evidence emerges about mechanisms by which ultra-processed foods drive health harms, these classification systems can be updated to reflect such evidence. If specific additives are found to be harmful to health, for example, this evidence can be incorporated into existing nutrient profiling systems, such as the Health Star Rating labelling scheme.
Accordingly, policymakers can confidently progress food policy implementation using the tools for classifying the healthiness of foods that we already have.
Unhealthy diets and obesity are among the biggest contributors to poor health. We can’t let the hype and academic debate around “ultra-processed” foods delay implementation of globally recommended policies for improving population diets.
