Foods to kill? Ultra-processed foods linked to increased mortality risk, study finds

13 Feb 2019 --- A 10 percent increase in the consumption of ultra-processed foods has been linked to a 14 percent increased risk in all-cause mortality, including obesity and cancer, according to a new Journal of the American Medical Association study. Published at a time when aspects such as fat, salt, sugar, and their impact on overall health, are under intense government and industry scrutiny, the study highlights the repercussions of a diet high in processed foods and their possible correlation with negative health outcomes.

Ultra-processed foods are foods that go through multiple processes, such as extrusion, molding and milling, and contain many added ingredients, as well as being highly manipulated. The study followed roughly 45,000 French adults for about seven years and found that the increased consumption of processed foods is associated with a higher mortality risk from any cause.

Despite these stark figures, the study has several limitations, however, as it is not entirely possible to determine a clear correlation between processed foods and poorer diet and lifestyle. 

When examining the participants’ backgrounds the study found that those who consumed more processed foods had lower incomes and levels of education, lived alone, had higher BMIs than average and were not very physically active. 

Of the participants studied, those who ate a lot of ultra-processed foods subsequently had diets that were high in saturated fats and sugars and lower in fiber.

“It can be more difficult for those on a lower income to make healthy choices. This is for a variety of reasons including access to foods, cost, perception and marketing,” Aisling Pigott, Dietitian and Spokesperson for British Dietetic Association, tells NutritionInsight.

Taking into account all the aforementioned factors, the researchers adjusted their approach to further include factors related to food processing such as additives, process contaminants or compounds formed at high temperatures that could be causing the association with mortality.

“It’s important to note that many foods have to be processed in some way before they are eaten, such as wholegrain breads and wholegrain, lower sugar breakfast cereals, and this does not make them inherently unhealthy,” Dr. Lucy Chambers, Senior Scientist for the British Nutrition Foundation, tells NutritionInsight.

Chambers says that while this new study is interesting and opens avenues for further research, there’s not enough data yet to understand which characteristics of ultra-processed foods might be associated with poorer health and if this link could be explained by other aspects of the diet and lifestyle of the people who consume these types of foods.

“We are already seeing government and industry drives to improve the sugar, salt and fiber content in [processed] foods which should be commended,” Pigott says.

Categorizing foods purely on their level of processing does not consider their nutrient content or allow us to select more healthy types of processed foods. 

“If you think about it, processed foods are almost everywhere. If we buy a packet of lettuce, for example, that is technically a processed food. We know that this study focuses on ultra-processed foods, which means foods such as pastries/pies/microwave meals,” Pigott explains. “The impact of these foods is often a double-edged sword as they are often of lower nutritional quality and have ingredients with an altered nutritional profile (secondary to the processing).”

“The UK government recommends that foods high in fat, salt and/or sugar such as biscuits, fried snacks and sugar-sweetened drinks, many of which could be categorized as ‘ultra-processed’, are not needed in the diet and we should all be eating less of them,” Chambers says.

She also suggests that people wishing to make healthy food choices should check food labels, avoid foods high in fat, salt and/or sugar and try to eat a diet that contains plenty of fruit and vegetables, whole grains, fish, pulses and unsaturated oils and not much red and processed meat, refined grains, sugar and saturated fat. 

By Kristiana Lalou