Cheeseburgers and fries on a food trayShare on Pinterest
Processed meat and dairy products are two of the foods highlighted in a new diet study. Alexander Spatari/Getty Images
  • Researchers say overall dietary quality may have a larger influence on risk of death than the consumption of ultra-processed foods.
  • In their 30-year study, they reported that some ultra-processed foods such as ready-to-eat meat products were major contributing factors to mortality.
  • The researchers add that their work highlights that ultra-processed foods don’t need to be universally restricted, but certain foods should be limited for longer term health.

Overall dietary quality has a greater influence on risk of death than the consumption of ultra-processed foods.

That’s according to research published today in the journal BMJ that states that certain ultra-processed foods are associated with a heightened risk of death.

“Our findings suggest that meat/poultry/seafood based ready-to-eat products and sugar sweetened and artificially sweetened beverages are major factors contributing to the harmful influence of ultra-processed foods on mortality, which is in accordance with previous studies,” the study authors wrote.

“The findings provide support for limiting consumption of certain types of ultra-processed food for long-term health. “On the basis of our data, limiting total ultra-processed food consumption may not have a substantial influence on premature death, whereas reducing consumption of certain ultra-processed food subgroups (for example, processed meat) can be beneficial,” they added.

The 30-year study tracked the health of more than 74,000 female nurses and 39,000 male health professionals.

Every two year participant in the study provided information about their lifestyle and health habits. Every four years the participants also completed a food questionnaire. The overall quality of their diet was then given a score.

The researchers reported that those who had an average of seven servings of ultra-processed foods per day had a 4% higher risk of death than their peers who had an average of three servings of ultra-processed foods a day.

Those who had the highest consumption of ultra-processed foods also had an 8% higher risk of neurodegenerative deaths.

Of the ultra-processed food groups, dairy-based desserts have the strongest association with death from neurodegenerative causes.

“Increasing evidence suggests that ultra-processed food is linked to higher risk of central nervous system demyelination (a precursor of multiple sclerosis), lower cognitive function, and dementia. Studies have shown that a diet rich in ultra-processed foods may drive neuroinflammation and impairment of the blood-brain barrier, leading to neurodegeneration,” the study authors wrote.

Ultra-processed foods include items such as cake, sugary cereal, baked goods, soft drinks, bacon, chicken nuggets, hot dogs, frozen pizza, and ready-to-eat or ready-to-heat meals.

During manufacturing, colors, flavors, emulsifiers and other additives may be added. As a result, many ultra-processed foods can be high in added sugars, salt, and saturated fat. They can also be low in fiber, vitamins, and nutritional value.

In the United States, 57% of the daily energy intake among adults is derived from ultra-processed foods. Among young people, it’s 67%.

More than 73% of the food supply in the United States is made up of ultra-processed foods.

A growing body of research has linked ultra-processed foods with heart disease, diabetes, and cancer.

However, researchers in the new study said that once they had taken overall diet quality into account, the association of ultra-processed foods on death was less pronounced.

They said this suggests that dietary quality may have a stronger influence.

The researchers argue their study highlights that not all ultra-processed food products should be restricted. Instead, certain kinds of ultra-processed foods such as meat, poultry, and seafood ready-to-eat meals could be limited with the focus being on overall diet quality.

“Diet quality looks at the total overall quality of someone’s diet,” Dana Hunnes, PhD, a senior dietitian supervisor at RR-UCLA Medical Center in California who was not involved in the study, told Medical News Today. “Is it filled with processed and ultra-processed foods or is it filled with non-processed foods such as whole fruits and vegetables, whole grains, nuts, seeds, legumes, etc. A good-quality/high-quality diet would be mostly non-processed foods, mostly whole foods as they grow from the ground versus ultra-processed foods that are unrecognizable and have been stripped of their nutritional quality (sometimes having it added back in through fortification) and therefore add calories and fat to the diet without the beneficial nutritional qualities of whole foods (including fiber).”

“You can occasionally eat ultra-processed foods if 95 percent of what you eat is whole, unprocessed foods and have good dietary quality,” Hunnes added. “Alternatively, you can eat a diet that is 90 percent ultra-processed/processed foods that don’t have much fiber and are unrecognizable and have extremely poor dietary quality. Ultra-processed foods occasionally have a place in a healthy diet. We cannot be fully healthy and eat 100 percent healthy all of the time, it’s not 100 percent feasible 100 percent of the time. That’s where the concept of diet quality comes in. The occasional ultra processed food is OK. Less though, is always better.”

The US Dietary Guidelines for Americans recommends a healthy eating plan that consists of fruits, vegetables, and whole grains as well as a variety of proteins, fat free or low fat milk and milk products, and foods that are low in cholesterol, trans fat, saturated fat, added sugar, and sodium.

Lauri Wright, PhD, the president of the Academy of Nutrition and Dietetics who was not involved in the study, says instead of buying ready-to-eat meals from the store, convenience foods can be prepared at home.

“I would recommend preparing meals at home and making ready-to-eat meals from the leftovers,” she told Medical News Today.

The BMJ study is observational, so firm conclusions cannot be made between cause and effect. The study authors say that the classification system of ultra-processed foods doesn’t fully account for the complexity of food processing, meaning some items could be misclassified.

“Future studies are warranted to improve the classification of ultra-processed foods and confirm our findings in other populations,” the study authors wrote.

Some you should avoid to improve overall health