Study suggests ultra-processed food can affect our brain health

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  • More and more people worldwide are consuming ultra-processed food.
  • Research, however, shows it can have concerning effects on our health, including our cognitive function.
  • Minimally processed foods, such as in the Mediterranean diet, are highly beneficial for health and longevity.

Globally, more and more people are receiving their total energy intake from ultra-processed foods. In South Africa, nearly 80% of packaged foods in our supermarkets are ultra-processed, a recent study revealed.

From breakfast cereals to mass-produced bread, biscuits, ice cream, sausages, crisps, chocolates, soft drinks, flavoured yoghurts, processed meats and frozen foods (such as pre-packaged pizzas and pies), ultra-processed foods are everywhere.

As explained by a nutritionist at Harvard University, unprocessed or minimally processed foods (in their natural, or nearly natural state) have their vitamins and nutrients intact. Ultra-processed foods, on the other hand, have numerous added ingredients, including artificial colourants, preservatives, sugar, salt, and fat. 

The average individual may find reading food labels tricky and time-consuming, so they never really know what’s in the foods they are consuming. A 2018 survey found that only about a third of South Africans regularly read food labels.

But we should pay more attention to these labels as ultra-processed foods can negatively impact cognitive functions, according to a new study.

The study

The research, which appears in the European Journal of Nutrition, highlights how consuming these foods can negatively impact the cognitive performance of older adults.

Just over 2 700 participants aged 60 and older (54% females) were involved in the study and underwent cognitive assessments. 

The participants were part of the National Health and Nutrition Examination Survey – using a combination of interviews and physical examinations to track the health and nutritional status of the Australian population – from 2011 to 2014. 

All participants were asked to recall the type and amount of food and beverages they ate in 24 hours on two non-consecutive days. 

Potential effects

One of the tests used by the research team, from Monash University in Melbourne, focused on Alzheimer’s disease. 

Unfortunately, their analysis revealed eating ultra-processed foods was linked to worse performances in participants who didn’t have any pre-existing diseases.

To the researchers’ knowledge, this is the first study to analyse the association between cognitive performance and ultra-processed food consumption in older adults. 

But this may be offset if switching to a healthier diet, such as the Mediterranean diet. Research over the years, such as this study, shows that this diet, typically high in whole grains, fruits, vegetables, nuts, legumes, seafood and unsaturated fats such as olive oil, is associated with a reduced risk for dementia as well as cognitive decline.

The authors noted some limitations in their work, including the cross-sectional nature of the study, which means that the results do not present a cause-and-effect relationship.

However, while longitudinal studies are needed to provide stronger evidence, “these results suggest that decreasing [ultra-processed food] consumption may be a way to mitigate age-associated cognitive decline and reduce the risk of dementia”, the team concluded.

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