In a recent study published in BMJresearchers investigated the relationship between ultra-processed food (UPF) intake and all-cause and all-cause mortality in the United States (US).
Study: Association of hyperprocessed food consumption with all-cause and specific mortality: a population-based cohort study. Image credit: Daisy Daisy/Shutterstock.com
Record
Highly processed foods, which are low-quality, high-energy-dense, ready-to-cook/heat industrial preparations, dominate the food supply in high-income countries and are increasingly common in middle-income countries.
These foods often have added sugars, salt, saturated fat, trans fat, refined carbohydrates, and poor fiber. They may also contain dangerous additives and contaminants.
Large-scale cohort studies suggest that highly processed foods have negative health effects, including overweight or obesity, cardiovascular disease, type 2 diabetes, colon cancer, metabolic syndrome, depression, postmenopausal breast cancer, and increased all-cause mortality.
However, there is insufficient research on the effect of UPF intake on mortality outcomes. High-quality evidence is vital for making dietary recommendations and developing food policy.
About the study
In the present population-based cohort study, researchers investigated whether UPF consumption increases all-cause or cause-specific mortality, especially cancer mortality.
The researchers conducted the study among female Nurses in the Health Study (NHS, 1984–2018, in 11 states) participants aged 30–55 and male Health Professional Follow-up Study (HPFS, 1986–2018) participants aged 40–75. .
Study participants included 74,563 women and 39,501 men without a history of cardiovascular disease, diabetes, or cancer, excluding those with unlikely caloric intake or missing UPF intake data.
Participants filled out questionnaires about their lifestyle habits and medical history every two years. The researchers assessed UPF intake using the NOVA classification and semiquantitative food frequency questionnaires at four-year intervals. They assessed diet quality using the Alternative Healthy Eating Index-2010 (AHEI) scores.
Follow-up time accumulated from the date of questionnaire return to the date of death or the end of the follow-up period (30 June 2018, for the NHS and 31 January 2018, for the HPFS), whichever occurred first.
Deaths were notified by descendants via mail in returned questionnaires or identified through the National Death Index and state vital records. The team identified cause of death using International Classification of Diseases, Eighth Revision (ICD-8) codes.
The researchers performed multivariate Cox proportional hazards modeling to determine hazard ratios (HRs) for the relationship between UPF intake and all-cause and cause-specific deaths from cardiovascular disease, cancer, and others, including neurodegenerative and respiratory causes.
Study covariates included race, ethnicity, smoking habits, alcohol consumption, physical activity, body weight, marital status, family history of diabetes, cardiovascular disease, cancer, menopause, and hormone use after menopause.
Results
Overall, 48,193 deaths were recorded, including 18,005 men and 30,188 women, during a median follow-up of 31 and 34 years, respectively.
By cause, 13,557 were cancer-related, 11,416 were due to cardiovascular disease, 3,926 deaths were of respiratory causes, and 6,343 were of neurodegenerative causes.
Individuals with higher UPF intake were physically inactive and younger, with increased body mass index values, lower AHEI scores, and increased likelihood of smoking.
Compared with subjects in the lowest quartile of median UPF intake (average of three servings per day), those in the upper quartile (seven servings per day) had a 4.0% higher rate of all-cause mortality (HR, 1.0) and 9.0% higher deaths due to causes excluding cardiovascular disease and cancer (HR, 1.1).
Deaths from any cause among people from the lowest and highest quartiles were 1,472 and 1,536 per 100,000 person-years, respectively.
Meat, seafood, and ready-to-cook foods derived from poultry (such as processed meats) consistently showed strong associations with death, with HR values between 1.1 and 1.4.
Artificial and sugary liquids (HR, 1.1), dairy desserts (HR, 1.1), and UPF breakfast foods (HR, 1.0) also contributed to higher all-cause mortality.
However, there were inconsistent relationships between UPF intake and death in each trimester of diet quality based on AHEI scores.
Conversely, improved dietary quality reduced mortality outcomes in each quartile of UPF intake. Associations between UPF consumption and all-cause mortality were stronger among people who did not currently smoke and those who consumed less alcohol.
The study found that eating more highly processed meals was associated with a slight increase in all-cause mortality, mainly due to ready-to-cook poultry/seafood/meat, sugary drinks, dairy-based desserts and highly processed breakfast dishes.
Therefore, careful consideration is required when including UPFs in dietary patterns, and their intake should be limited for long-term health reasons.
However, the impact of dietary quality was more profound than UPF intake on mortality. Further research can strengthen the evaluation of UPF and confirm the findings in different groups.
