A high consumption of ultra-processed foods (i.e. almost any consumable food item, except fresh fruits and vegetables) is associated with an increased risk of cardiovascular disease and mortality, show two studies in BMJ.
Findings from two studies recently published in the British Medical Journal highlight the clear impact of consuming ultra-high processed foods to the risk of cardiovascular events and overall mortality.
In a study led by Bernard Srour, M.D., of the University of Paris, researchers found that a 10 percent increase in the consumption of ultra-processed foods corresponded to increases in coronary heart and cerebrovascular disease of 13 and 11 percent, respectively, and a 12 percent overall increase in total cardiovascular disease.
The authors highlight the need for improvements in nutritional quality and a reduction in the use of unnecessary additives.
“Various factors in processing, such as nutritional composition of the final product, additives, contact materials, and neoformed contaminants might play a role in these associations,” they wrote. “Further studies are needed to understand the relative contributions.”
While other studies have linked the consumption of ultra-processed food to increased risks of cancer and cardiometabolic disorders, including obesity, hypertension and high cholesterol, this is the first epidemiological study to show an association between a diet high in processed foods and the risk of cardiovascular disease.
The study included 105,159 adults (79.2 percent women, average age 42.7 years). Dietary habits were recorded for 24-hour periods over an average of 5.2 years in which 1,409 participants experienced their first cardiovascular event: 106 myocardial infarctions, 485 angioplasties, 74 acute coronary syndromes, 155 strokes, and 674 transient ischaemic events.
The amount of ultra-processed foods consumed was found to be directly correlated with the incidence of cardiovascular disease: 277 of 100,000 person years for high consumers as compared 242 among low consumers and 253 for the entire population.
The group who consumed the most amount of ultra-processed foods tended to be younger, current smokers, less educated and be less physically active. They also consumed more foods high in carbohydrates and sodium. They consumed less alcohol, but also less fruit, vegetables, and foods rich in fiber. Even though this group had a higher BMI, they had a lower prevalence of metabolic diseases and less of a family history of cardiovascular disease suggesting the onset of cardiovascular disease in this group could very well be acquired.
“It is important to inform consumers about these associations and to implement actions targeting product reformulation taxation, and communication to limit the proportion of ultra-processed foods in the diet and promote the consumption of unprocessed or minimally processed foods instead,” the authors wrote.
An observational study published in the same issue of British Medical Journal by Maira Bes-Rastrollo, M.D., of the University of Navarra in Spain, evaluated all-cause mortality for 19,899 adult men (7,786) and women (12,113) who were followed every two years between December 1999 and February 2014.
Researchers found that the consumption of four or more servings of ultra-processed foods per day was independently associated with a 62 percent “relatively increased hazard” for all-cause mortality as compared to those who consumed less than two servings. For each additional serving of ultra-processed food, all-cause mortality increased by 18 percent.
Participants who consumed high amounts of ultra-processed foods had a higher hazard for all-cause mortality compared to those who consumed the least amount of ultra-processed foods. The main cause of death was cancer (n=164, mean age 58 years).
“Our results suggest that an increased consumption of ultra-processed food is associated with a higher hazard of all-cause mortality. Improving diet based on adherence to minimally processed food-a key aspect of the Mediterranean diet-has been shown to protect against chronic disease and all-cause mortality,” researchers wrote. “Discouraging the consumption of ultra-processed foods; targeting products, taxation, and marketing restrictions on ultra-processed products; and promotion of fresh or minimally processed foods, should be considered part of important health policy to improve global public health.”
WHAT ARE THEY EATING?
Consuming ultra-processed food products has become a way of life for most people in the U.S., European countries, Canada, New Zealand and Latin American countries where these products represent up to 60 percent of an individual’s daily diet intake.
Ultra-processed foods include prepared foods with ingredients that are high in total fat, sugar and salt. These foods are usually low in fiber and nutrients, but are associated with a high glycemic load which leave consumers craving more. This combination can take a toll on cardiovascular health, but in ways the average consumer may not realize. Heat-treated food products contain contaminants such as acrylamide and acrolein which may be associated with cardiovascular disease risk, according to a previous study. They also contain additives, such as glutamates, emulsifiers, sulfites and carrageenan, which have been linked to adverse cardiometabolic effects in animal models.
Foods in the Srour et al. study were categorized into one of four groups ranging from low to high intake:
Ultra-processed foods: Mass produced packaged breads, sweet or savory snacks, confections and desserts, sodas and sweetened beverages; processed meatballs, poultry and fish nuggets, and other reconstituted meat products transformed with the addition of preservatives other than salt (such as sodium nitrite); instant noodles and soups, frozen or shelf stable ready meals, and food products made mostly or entirely from sugar, oils, and fats and other substances such as hydrogenated oils, modified starches and protein isolates.
Processed foods: Canned vegetables with added salt, sugar-coated dried fruit, meat products only preserved by salting, cheeses and freshly made unpackaged breads, and other products manufactured with the addition of basic food ingredients such as salt and sugar.
Unprocessed or minimally processed foods: Fresh, dried, grounded, chilled, frozen, pasteurized or fermented staple foods such as fruit, vegetables, pulses, rice, pasta, eggs, meat, fish, or milk; salt, vegetable oils, butter, sugar, and other substances extracted from foods and used in kitchens to transform unprocessed or minimally processed foods.
Ultra-processed foods are most commonly known to be associated with weight gain, obesity, metabolic syndrome and functional gastrointestinal disorders, and now a French study documented as association to cancer and breast cancer.
Not only are the ingredients harmful, but so too is the packaging which can include bisphenol A, which could increase the risk of cardiometabolic disorders, research shows.
At least 350 additives are allowed in processed foods, the culmulative impact of which are largely unknown. Heat processes used to manufacture these foods often produce known neoform contaminants, and packaging materials and containers used in distribution may also leach contaminants into the food.
Results from these two studies form the basis of a wave of new research into specific features of ultra-processed food consumption that are likely to impact clinical and public health policy directives regarding diet.
Dr. Srour and his research team are currently conducting research that examines the health effects of chronic exposure to food additives, and eventually they will be exploring the effects of microwavable food containers for ready-made meals on health.
“Further studies are needed to investigate the relative impact of nutritional composition, food additives, contact materials, and neoformed contaminants in this association,” he and colleagues wrote.
MORE FROM ENDOCRINOGY NETWORK ON NUTRITION
Srour B, Fezeu LK, Kesse-Guyot E, et al. “Ultra-processed food intake and risk of cardiovascular disease: prospective cohort study (NutriNet-SantÃ©).” BMJ. May 29, 2019. DOI:10.1136/bmj.l1451.
Rico-CampÃ A, MartÃnez-GonzÃ¡lez MA, Alvarez-Alvarez I, et al. “Association between consumption of ultra-processed foods and all-cause mortality: SUN prospective cohort study.” BMJ. May 29, 2019 DOI: 10.1136/bmj.l1949.