Processed Foods Linked to Shorter Life Span, Study Finds
The study focused on highly processed foods, such as ready-made meals, energy bars, and ice cream.
You might turn to the vending machine when hunger strikes, but a new study suggests ultraprocessed foods — those manufactured industrially with multiple ingredients and additives — may take years off your life.
The study, published on February 11, 2019, in the journal JAMA Internal Medicine, used self-reported data from 44,551 participants in the French NutriNet-Santé Study, an ongoing study that started in 2009. Study participants shared their food logs over a median of 7.1 years. The mean age at the start was 56.7 years, and 73 percent of the participants were women.
In the study group, ultraprocessed foods accounted for almost 34 percent of participants’ average daily calorie intake. Researchers observed that a 10 percent increase in eating these types of foods was linked to a 14 percent higher risk of early death from any cause. In other words, study authors observed that when ultraprocessed foods were a bigger part of an individual’s diet, that person seemed to have an increased risk of early death.
While the study was done in France, researchers note that Americans consume more ultraprocessed foods (58 percent of their daily calorie intake) than the study group.
“We might therefore think that these associations could be stronger in the U.S. population, as the Americans might consume more ultraprocessed foods,” say study authors Bernard Srour, PharmD, MPH, and Mathilde Touvier, PhD, both of the University of Paris 13 and the National Epidemiology Research Team. Because the study participants are volunteers who are more conscious about their health and nutrition, it’s possible that the general population eats more ultraprocessed foods, researchers add.
What Qualifies as ‘Processed’ Food Exactly?
The study defined processed food using the NOVA food classification system, which categorizes food products in four groups. Group 1 foods are unprocessed or minimally processed foods obtained directly from plants or animals, like fresh fruits and milk. Group 2 foods are substances derived from unprocessed foods, such as oils, butter, sugar, and salt. Group 3 foods are “processed” and made by adding salt, oil, and other ingredients to unprocessed or minimally processed foods; for example, fruit in syrup and freshly made bread. Group 4 foods are “ultraprocessed” and include carbonated drinks, ice cream, energy bars, ready-to-eat meals, and hot dogs.
“When processed food is made, they typically add salt, sugar, and fat, and probably take away vitamins, minerals, and fiber naturally present in those foods. There’s concern about both sides of that — what’s added and how it affects your health and what’s removed and how it affects your health,” says Lynn Grieger, RDN, CDE, a health, food, and fitness coach in private practice in Prescott, Arizona. Grieger, who is also a medical reviewer for Everyday Health, was not involved in the study.
The French government has the goal of reducing the consumption of ultraprocessed food by 20 percent before 2021. Based on their findings and the French national nutritional requirements, the study authors recommend reducing how much ultraprocessed food you eat, in favor of fresh and unprocessed food.
Greiger agrees, adding that a study published in January 2016 in the journal BMJ Open found that ultraprocessed foods contribute to nearly 90 percent of all added sugar intake in the United States.
“Every [U.S.] health organization has come out to recommend we eat less sugar because of the negative health impact,” she says. As for other additions used to create processed food, “sodium is directly related to cardiovascular health, especially blood pressure and risk of stroke. Fat seems to make a difference both in cardiovascular disease, and in some types of cancer,” she says.
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How Might Processed Foods Be Harmful for Your Health?
The study’s limitations included that the participants self-reported their food logs, and that participants are more health-conscious than the general population, which may mean that the mortality rates and ultraprocessed foods intake are likely lower than the general population. The follow-up period was relatively short, researchers note, and the majority of participants were women.
Study authors say more research is needed to confirm their findings, but suggest that the nutritional profile of these ultraprocessed foods, additives, and industrial food processing may be to blame. Here’s how they explain it:
Nutritional Quality On average, ultraprocessed foods tend to be poorer in fiber and vitamins, and contain more sugar, salt, and saturated fatty acids. But the study accounted for nutritional quality, so it probably doesn’t fully explain their findings, they say.
Food Additives In animal studies, some food additives have been shown to have effects on chronic disease. According to a review published in November 2017 in the journal Frontiers in Immunology, thickeners, preservatives, and artificial sweeteners may affect immune function, and contribute to metabolic diseases, such as obesity and type 2 diabetes.
Plastic Packaging Ultraprocessed foods are often packaged in plastic that has substances that can migrate into the food. BPA (bisphenol A), which is commonly found in certain plastics and canned goods, may disrupt hormone levels and affect women’s reproductive health, according to a study published in October 2015 in the International Journal of Environmental Research and Public Health.
Compounds Formed During Processing Some compounds, such as acrylamide and acrolein, which form due to high temperature heating, may be associated with increased incidence of cardiometabolic diseases, according to a study published in August 2014 in the Journal of the American Heart Association.
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4 Tips for Eating Less Processed Food
In general, you should try to eat foods that are not processed or are minimally processed, but it can be hard to avoid heavily processed foods. Grieger says the study’s findings are a reminder that you can make healthier, thoughtful choices. She suggests a few ways to make small changes:
- Read the nutrition facts labels and choose an option with the least amount of sodium and added sugar. The Dietary Guidelines for Americans from the Office of Disease Prevention and Health Promotion recommends Americans eat less than 2,300 mg of sodium per day. Calories from added sugar should be no more than 10 percent each day; for a 2,000 calorie diet, that’s about 12 teaspoons.
- Look for a minimal number of ingredients and for ingredients that you recognize in packaged foods.
- Cook dinner at home once per week instead of going out.
- Buy more fresh fruit instead of processed kinds (such as those canned and in syrup). Frozen fruit is picked at peak freshness and is also a healthy option.
“It’s important to remember that health is complex; it’s not just one thing, it’s a bunch of small things,” Grieger says. “I want to empower people to say, ‘Yes, I can make a choice, I can read a food label and choose something that isn’t as highly processed.’”