Eating too much ultra-processed food could speed up the biological ageing process, Monash University-led research has found.
Published in the journal Age and Ageing, the study showed an association between increased consumption of ultra-processed foods (UPF) and biological ageing. For every 10% increase in UPF consumption, the gap between biological and chronological age rose by 2.4 months.
UPFs include foods such as chips, carbonated drinks, instant noodles, ice cream, chocolate, biscuits, ready-to-eat meals, sausages, burgers, chicken and fish nuggets, sweet or savoury packaged snacks and energy bars.
The cross-sectional study assessed data involving 16,055 people from the US aged 20–79, whose health and lifestyles were comparable to those in other western countries such as Australia.
First author Dr Barbara Cardoso, from Monash University’s Department of Nutrition, Dietetics and Food and Monash Victorian Heart Institute, said the findings underlined the importance of eating as many unprocessed and minimally processed foods as possible.
Cardoso said the association between UPFs and markers of biological ageing was under-investigated, despite the obvious adverse health effects of these foods.
“The significance of our findings is tremendous, as our predictions show that for every 10% increase in ultra-processed food consumption there is a nearly 2% increased risk of mortality and 0.5% risk of incident chronic disease over two years,” she said
“Assuming a standard diet of 2000 calories (8500 kilojoules) per day, adding an extra 200 calories of ultra-processed food, which roughly equals an 80-gram serving of chicken bites or a small chocolate bar, could lead to the biological ageing process advancing by more than two months compared to chronological ageing.”
The study used data from the US National Health and Nutrition Examination Survey (NHANES) 2003–2010. Diet quality was assessed with the American Heart Association (AHA) 2020 and the Healthy Eating Index 2015 (HEI-15). Biological ageing was assessed using the PhenoAge algorithm.
For each 10% of energy intake by UPFs, participants were 0.21 years biologically older. Compared to participants in the lowest UPF quintile (39% or less of their diet was UPF), those in the highest UPF quintile (68–100% of their diet was UPF) were 0.86 biological years older.
The association between UPF intake and biological ageing remained significant after adjusting for diet quality and total energy intake.
This suggested the association could be due to other factors such as lower intake of flavonoids or phytoestrogens, which occur in natural foods such as fresh fruit and vegetables, or higher exposure to packaging chemicals and compounds formed during food processing.
“Adults with higher UPF tended to be biologically older,” the study found. “This association is partly independent of diet quality, suggesting that food processing may contribute to biological ageing acceleration. Our findings point to a compelling reason to target UPF consumption to promote healthier ageing.”
The results also supported earlier research linking UPF consumption to ageing markers such as telomere length (a shorter telomere length is a sign of cell ageing), frailty, cognitive decline and dementia.
Cardoso said while the study participants were in the USA, the relevance of the findings apply to Australians too, as on average, ultra-processed foods represented almost 40% of total energy intake among Australian adults.
She said given the global population continued to age, demonstrating the adverse effects of UPFs reinforced the need for dietary-focused public health strategies to prolong a healthy life span.
“Our findings show that reducing ultra-processed foods in the diet may help slow the biological ageing trajectory, bringing another reason to target ultra-processed foods when considering strategies to promote healthy ageing,” she said.