Regular intake of ultra-processed food ups risk of CVD, all-cause mortality

High consumption of ultra-processed food (UPF) may result in a heightened risk of cardiovascular disease (CVD) and all-cause mortality, driven partly by its high sugar content, according to a study.

“Some established biomarkers of CVD risk were likely to be on the pathway of such associations,” the researchers said. “These findings should serve as an incentive for limiting consumption of UPF, and encouraging natural or minimally processed foods, as several national nutritional policies recommend.”

A longitudinal analysis was performed on 22,475 men and women (mean age, 55 years) recruited in the Moli-sani Study (2005–2010, Italy) and followed for 8.2 years. A semiquantitative food frequency questionnaire was used to assess food intake. The researchers defined UPF using the NOVA classification according to degree of processing. In addition, UPF intakes were categorized as quartiles of the ratio of UPF to total food consumed.

Individuals with the highest UPF intake (Q4, >14.6 percent of total food), as compared with the lowest (Q1, UPF <6.6 percent), showed increased risks of CVD mortality (hazard ratio [HR], 1.58, 95 percent confidence interval [CI], 1.23–2.03), death from ischaemic heart disease (IHD)/cerebrovascular disease (HR, 1.52, 95 percent CI, 1.10–2.09), and all-cause mortality (HR, 1.26, 95 percent CI, 1.09–1.46). [Am J Clin Nutr 2021;113:446-455]

A good portion (36.3 percent) of the association between UPF intake and IHD/cerebrovascular mortality was driven by high sugar content, while other nutritional factors, such as saturated fats, were not likely to be on the pathway. Moreover, biomarkers of renal function were responsible for 20.1 percent of the relation of UPF with all-cause mortality, and 12.0 percent for that with CVD mortality.

“[I]n line with the high energy density hypothesis suggesting that UPFs may promote excess energy intake because of their high energy density, energy content was on the UPF–mortality pathway, although limited to IHD/cerebrovascular death,” the researchers said. [Curr Obes Rep 2017;6:420-431]

The unfavourable relation between UPF and mortality risk, however, was only partly accounted for by nutrients present in large quantities in such foods. This suggested that nutrient composition alone could not fully explain the increased mortality risk associated with higher UPF consumption, in line with previous studies. [Prev Med 2015;81:9-15; Am J Hypertens 2017;30:358-366; BMJ 2019;365:l1949; Public Health Nutr 2019;22:1777-1785]

“Moreover, we should acknowledge that a higher proportion of the observed association may be explained by other dietary factors contained in UPFs not explored here,” the researchers said.

These findings were consistent with previous data on >100,000 French adults, which concluded that higher UPF consumption correlated with elevated risks of CVDs, IHD, and cerebrovascular diseases. [BMJ 2019;365:l1451]

“Although a direct comparison with other epidemiological studies is difficult owing to different assessments of UPF, it is of note that others provided similar results in terms of increased mortality risk being associated with higher UPF intake,” the researchers said. [BMJ 2019;365:l1949; Public Health Nutr 2019;22:1777-1785]

“Further longitudinal studies on dietary behaviours reflecting the modern food supply are needed to support our associations, but more urgently, there is a clear need for randomized controlled trials to document the effects on health of increasing UPF that are independent from differences in nutrient content or the types of foods consumed,” they noted. [BMJ 2019;365:l2289; Curr Obes Rep 2017;6:420-431]