- A diet high in ultra-processed foods could increase the risk of death among older Americans by up to 10%, a new study finds.
- The study followed the diet and health of more than half a million participants for more than 20 years.
- The highest level of ultra-processed food consumption was observed among the youngest members of the researcher’s older adult cohort.
Consumption of ultra-processed foods is linked to an increased risk of mortality in older adults, a new comprehensive study suggests.
People who ate high amounts of ultra-processed foods were 10% more likely to die over the study’s long follow-up period than those who did not.
The study drew on data from
The researchers assessed their diet using the NOVA system, which classifies foods based on the degree and type of processing used in their preparation.
They looked at Healthy Eating Index (HEI)-2015 scores, not just NOVA treatment, and noted that people with higher UPF intake tended to have lower diet quality and higher BMI.
What makes this study notable, in particular, are the two approaches the researchers used to further validate food frequency questionnaires (FFQs): expert consensus and an alternative, novel diet-based approach to defining FFP (grams per day) intake, which was broken down into food codes, then ingredient codes, and then categorized via NOVA.
The researchers also used two 24-hour dietary recalls in a subgroup to calibrate their FFQ risk estimates, which is not common practice and adds to the potential rigor of the study results.
The research was presented this week at the American Society for Nutrition’s NUTRITION 2024 conference.
According to the NOVA system, natural, processed and ultra-processed foods are defined as follows:
- Unprocessed, or natural, foods come directly from plants or animals without any alteration or transformation, other than transportation to where they are sold.
- Minimally processed foods are similar, except that they have been cleaned and inedible or unwanted parts have been removed. They may be cut into portions, ground, dried, fermented, pasteurized, chilled, or frozen before serving. However, no oils, fats, sugars, salt, or other substances have been added to them.
- NOVA also includes a category called Processed Culinary Ingredients, which are substances extracted from natural foods. These include oils, fats, salt, and sugar, which are ideally used in small amounts to season and cook foods without degrading the overall nutritional quality of the food.
- Processed foods are foods that have been made to be eaten by adding sugar, salt, and oil to natural foods to give them flavor and extend their shelf life. They usually contain no more than two or three ingredients.
- Ultra-processed foods, or UPFs, are industrial creations made primarily from substances including oils, fats, sugars and proteins derived from natural foods, as well as modified starches and hydrogenated fats, with added colors and flavor enhancers. They are inexpensive and convenient for the consumer, and may contain five or more ingredients.
It is well known that a diet high in ultra-processed foods can be harmful to health. However, the large number of people in this study (318,889 men and 221,607 women) and the long duration of follow-up are unusual.
Registered dietitian Kristin Kirkpatrick, MS, RDN, who was not involved in the study, said, “The very long follow-up period is interesting. However, the researchers also note that it’s not clear what was done between the time the data was collected and the follow-up. Did these people change their diet? Were there other activities that were risky for overall health? We don’t know the details.”
Compared to the lowest consumption of processed foods, the highest amount wasassociated with increased risks of death from heart disease and diabetes, but not death from cancer.
“This research shows that higher consumption of ultra-processed foods is associated with an increased risk of mortality, independent of other factors such as smoking, obesity and diet quality,” said Michelle Routhenstein, MS, RD, CDCES, a preventive cardiology dietitian at EntirelyNourished.com, who was also not involved in the research.
“This suggests that the adverse health effects of ultra-processed foods may persist regardless of general lifestyle factors,” Routhenstein said.
“Ultra-processed foods are typically higher in added sugars, unhealthy fats, and additives, while lacking essential nutrients such as fiber and vitamins, which can negatively impact cardiometabolic health. These foods contain higher levels of advanced glycation end products (AGEs) due to their processing methods, which can increase oxidative stress and inflammation in the body. AGEs can also increase cystatin C levels, which is associated with decreased kidney function and increased risk of cardiovascular disease.”
— Michelle Routhenstein, M.Sc., Dt.P., CDCES
Given the extended follow-up period, participants were approximately 73 to 94 years old at follow-up.
“Research on the impact of ultra-processed foods on older adults is limited but growing. The specific long-term impact on mortality in older populations remains an active area of study,” Routhenstein said.
“It’s never too late to make beneficial changes to your diet,” Kirkpatrick said. “Previous research has shown similar results regarding lifespan, such as a study that assessed UPF in people ages 57 to 91.”
She noted that much of the research she sees is in younger people and focuses on preventing later problems through better nutrition.
The researchers found that younger members of their study population tended to consume more UPF than older members.
“Younger participants, particularly middle-aged individuals, may consume more ultra-processed foods due to factors such as convenience, price and advertising. These foods are often widely available, require minimal preparation and are heavily marketed, making them attractive to active lifestyles,” Routhenstein said.
It may also be, Kirkpatrick noted, that “younger individuals who are generally healthy and have not had symptoms or serious illness are not thinking today about what the future holds for them with respect to their diet.”
The American diet typically contains a significant number of foods that span the spectrum of processing.
“Some of these foods, like breakfast cereals for example, can even help fill some nutritional gaps through fortification,” Kirkpatrick said.
However, she added, “consuming a lot of these foods means not having the opportunity to nourish the body with more nutrient-dense options.” The result can be a high consumption of high-calorie, nutrient-depleted foods.
Kirkpatrick expressed concern about the overreliance on the NOVA classification system to assess the impact of processed foods.
“The NOVA scale is strictly related to the degree of processing and has nothing to do with the nutritional value of foods, so it does not take into account elements such as added sugar, protein or fiber content,” she explained.
“Lumping all processed foods into one category risks oversimplifying nutritional science, so limiting UPF should also go hand in hand with educating individuals,” Kirkpatrick said.
“There is no one-size-fits-all dietary approach, so each patient may deserve a personalized approach based on their dietary needs and goals,” she said.