“This is another large, long-term study confirming the association between ultra-processed food intake and all-cause mortality, particularly from cardiovascular disease and type 2 diabetes.”

Consuming ultra-processed foods could shorten life expectancy by more than 10%, according to a new, as-yet-unpublished study of more than 500,000 people that researchers followed for nearly three decades.

The risk rose to 15% for men and 14% for women after adjusting for the data, explains the study's lead author, Erica Loftfield, a researcher at the National Cancer Institute in Bethesda, Maryland.

When asked about their consumption of 124 foods, people in the 90th percentile for ultra-processed food consumption said that highly processed beverages were at the top of their list.

“Diet soft drinks were the main contributor to ultra-processed food consumption. The second contributor was sugary soft drinks,” Loftfield says. “Beverages are a very important component of the diet and contribute to ultra-processed food.”

According to the study, refined grains, such as ultra-processed breads and pastries, are next in popularity.

“This is another large, long-term study that confirms the association between ultra-processed food intake and all-cause mortality, especially cardiovascular disease and type 2 diabetes,” said Carlos Monteiro, professor emeritus of nutrition and public health at the University of São Paulo, via email.

Montero used the term “ultra-processed foods” and created New food classificationwhich goes beyond nutrients and food production methods. Monteiro was not involved in the study, but several members of the NOVA classification system co-authored it.

This rating system rates foods from unprocessed or minimally processed foods — whole foods, such as fruits and vegetables — to ultra-processed foods, such as deli meats and sausages. Ultra-processed foods contain ingredients that are “never or rarely used in kitchens or in categories of additives whose function is to make the final product tasty or more appealing,” according to the report. Food and Agriculture Organization of the United Nations.

The list of additives includes preservatives to resist mold and bacteria; emulsifiers to prevent separation of incompatible ingredients; synthetic dyes and paints; anti-foaming, bulking, whitening, gelling, and glazing agents; and added or modified sugar, salt, and fats to make food palatable.

Health risks associated with processed meats and soft drinks

The initial study, presented at the annual meeting of the American Dietetic Association in Chicago, analyzed dietary data collected in 1995 from about 541,000 Americans ages 50 to 71 who participated in the American Diet and Health Study. National Institutes of Health (Arb)

The researchers linked dietary data to mortality rates over the next 20 to 30 years. The study showed that compared with people in the bottom 10 percent of ultra-processed food consumption, people who ate the most processed foods were more likely to die from heart disease or diabetes. However, unlike other studies, the researchers did not find an increase in cancer-related deaths.

Some ultra-processed foods carry greater risks than others, says Loftfield: “Highly processed meats and soft drinks were among the subgroups of ultra-processed foods most strongly associated with mortality risk.”

Diet drinks are considered ultra-processed foods because they contain artificial sweeteners, such as aspartame, acesulfame potassium, and stevia, as well as additional additives not found in whole foods. Diet drinks have been linked to an increased risk of premature death from cardiovascular diseases, such as the onset of dementia, type 2 diabetes, obesity, stroke, and metabolic syndrome, which can lead to heart disease and diabetes.

The Dietary Guidelines for Americans already recommend limiting sugary drinks, which have been linked to premature death and the development of chronic disease. A March 2019 study found that women who drank more than two servings a day of sugary drinks — defined as a regular cup, bottle or can — had a 63% higher risk of early death than those who drank them less than once a month. Men who did the same had a 29% higher risk.

Processed meats, such as bacon, hot dogs, sausages, ham, deli meats, cured meats and cold cuts, are also not recommended; research has linked red and processed meat to bowel and stomach cancer, heart disease, diabetes and premature death from any cause.

“The data from this new study suggests that processed meat may be one of the most unhealthy foods for you, but people don’t tend to think of pork or chicken nuggets as ultra-processed foods,” said Rosie Green, professor of environment and food and health at the London School of Hygiene & Tropical Medicine, in a statement. Green was not involved in the study.

The study found that people who ate more ultra-processed foods were younger, heavier, and had poorer diet quality than those who ate less processed foods. However, the increased health risks cannot be explained by these differences, because even people of normal weight who followed a healthy diet were also at risk of premature death from ultra-processed foods, the research shows.

“Studies that use food rating systems like NOVA, which focus on degree of processing, rather than nutritional composition, should be viewed with caution,” warns Carla Saunders, president of the Calorie Control Council of North America, an industry association, via email.

“Suggesting that we should eliminate diet foods such as low- or low-calorie drinks, with proven benefits in treating diseases such as obesity and diabetes, is harmful and irresponsible,” Saunders asserts.

Results may reduce risks

One major limitation of the study is that the dietary data was collected only once, about 30 years ago, and “it’s hard to say how eating habits have changed between then and now,” Green laments. However, the manufacture of ultra-processed foods has exploded since the mid-1990s, with estimates suggesting that about 60 percent of the average American’s daily calories come from ultra-processed foods. That’s not surprising, considering that 70 percent of the foods in any grocery store can be ultra-processed.

“However, we may underestimate ultra-processed food consumption in our study because we were so conservative,” Loftfield says. “It’s possible that intake has increased over the years.”

In fact, a study published in May found similar results—a higher risk of premature death and cardiovascular death in more than 100,000 health care workers who ate ultra-processed foods—that looked at ultra-processed foods intake every four years. It found that consumption doubled between the mid-1980s and 2018.

“For example, daily consumption of packaged savory snacks and desserts containing dairy products such as ice cream has essentially doubled since the 1990s,” says lead author of the Mayo study, Ming-Yang Song, an assistant professor of clinical epidemiology and nutrition at the Harvard School of Public Health.

“In our study, as in this new study, the positive association was driven mainly by a few subgroups, including processed meats and sugary or artificially sweetened beverages,” Song explains. “However, all categories of ultra-processed foods were associated with increased risk.”

Loftfield suggests that choosing more minimally processed foods is one way to reduce ultra-processed foods in one's diet.

“We should focus on eating meals that are rich in whole foods,” he adds. “And if foods are highly processed, look at the levels of sodium and added sugars and try to make the best decision you can, using the nutrition label.”