Written by Angeline A. De Leon, Staff Writer. Study finds that processed meat but not red meat, is significantly associated with higher mortality risk and recommends healthier protein substitutions.

health hazard - processed meatThe relationship between dietary intake of meat and general health outcomes has typically been a complex one. Research indicates that intake of processed meat is positively associated with overall mortality 1,2, but intake of red meat is inconsistently associated with total mortality 3. For processed meat also, the link to cause-specific mortality is less consistent, though most typically associated with cardiovascular and cancer mortality 1,4. Processed meat intake has also been linked to respiratory mortality 5, with cured meat intake being specifically linked to risk of chronic obstructive pulmonary disease (COPD) 6. Other dietary protein sources, such as poultry, eggs, fish, nuts, and dairy, also show a variable relationship to mortality, with nut consumption showing a consistent inverse association 7, and intake of poultry, eggs, and legumes showing generally inconsistent results 8,9. To help elucidate the relationship between mortality and different types of meat and dietary protein sources, a 2019 study 10 in the European Journal of Epidemiology looked at the association of overall and cause-specific mortality with red meat, processed meat, and other dietary protein sources.

A total of 120,852 participants (aged 55-69 years) were enrolled in a prospective cohort study. At baseline, subjects completed a food-frequency questionnaire (FFQ) in which they reported average daily intake of meat (fresh and processed), fish, eggs, dairy, legumes, and nuts. After about a 10-year follow-up period, data on mortality and causes of death were obtained from linkage with the Dutch Central Bureau of Genealogy and Statistics Netherlands. Case-cohort analyses were conducted based on 8823 deaths and 3202 subcohort members with complete dietary data.

Red meat (unprocessed) was neither significantly associated with overall mortality nor with cause-specific mortality. Processed meat, however, was significantly positively associated with overall mortality: when comparing highest (median intake = 30.8 g/day) vs. lowest intake quintile (median intake = 0 g/day), the Hazard Ratio was 1.21 (95% Confidence Interval: 1.02 to 1.44) (Ptrend = 0.049). Processed meat intake was also significantly associated with CVD mortality (HR = 1.26, 95% CI: 1.01 to 1.56) (Ptrend = 0.047) and respiratory mortality (HR = 1.79, 95% CI: 1.19 to 2.67) (Ptrend = 0.007). In general, fish intake showed positive associations with mortality, while nut intake showed inverse associations. Substitution analyses also revealed that replacing 50 g/day of processed meat with 50 g/day of a combination of poultry, eggs, fish, legumes, nuts, and low-fat dairy was associated with 11% lower risk of overall mortality, 20% lower risk of CVD mortality, and 37% lower risk of respiratory mortality.

Findings from the study point to a significant relationship between consumption of processed meat and higher overall risk of mortality, as well as CVD mortality and respiratory mortality. Given that nitrite, a preservative found in cured meats like bacon and ham, was also found to be significantly associated with overall mortality, CVD mortality, and respiratory mortality in the present study, nitrite ingestion is hypothesized to be involved in the relationship between processed meat intake and mortality. An important finding in this study was the lowered risk of mortality associated with substituting processed meat with other dietary sources of protein (e.g., poultry, eggs, fish, etc.). Further studies are needed to confirm whether substituting alternative protein sources for red meat is similarly associated with lower mortality risk. Study limitations to consider include the lack of updated dietary data at the time of follow-up and the potential inaccuracies associated with self-report measures like the FFQ.

Source: Van Den Brandt PA. Red meat, processed meat, and other dietary protein sources and risk of overall and cause-specific mortality in The Netherlands Cohort Study. European Journal of Epidemiology. 2019; 34: 351-369. DOI: 10.1007/s10654-019-00483-9.

© The Author(s) 2020. Published by Oxford University Press on behalf of the British Geriatrics Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/).

Click here to read the full text study.

Posted April 22, 2020.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

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