In a recent study published in The Lancet Planetary Health, researchers developed a microsimulation model, micro-Simulation of the Health Impacts of Food Transformations (mSHIFT), to evaluate the impact of reducing processed and unprocessed meat intake on cardiovascular disease, diabetes mellitus type 2, colorectal cancers, and death rates in the United States (US).
Background
Cardiovascular disease and cancer are the top two causes of mortality in the United States. Processed and unprocessed meat consumption is related to an elevated risk of chronic illnesses such as type 2 diabetes and colorectal cancer. However, the link between unprocessed meat and certain disorders is unclear.
Randomized controlled trials have not revealed such relationships, particularly in healthy dietary patterns involving modest consumption of unprocessed meat. There is yet insufficient evidence to make conclusive recommendations.
About the study
In the present microsimulation study, researchers investigated whether reducing processed and unprocessed meat intake could reduce the incidence rates of cardiovascular disease, type 2 diabetes, colorectal cancers, and deaths among US adults.
The researchers created the mSHIFT model to predict the effects of restricting processed and unprocessed meat intake on cardiovascular disease, diabetes mellitus type 2, colorectal cancers, and mortality rates. They obtained data from the United States National Health and Nutrition Examination Surveys (NHANES) conducted from 2015 to 2016 and 2017 to 18 to simulate the United States population.
The researchers included non-pregnant individuals with two-day dietary recall data in the initial cohort. They evaluated unprocessed and processed meat intake by combining NHANES dietary-recall information with the relevant item codes in the Patterns Equivalents Database. Subsequently, they calculated the average unprocessed and processed meat content of all foods reported by respondents on both days.
The researchers calculated baseline cardiovascular disease risk using the Framingham risk score (FRS) and baseline colorectal cancer risk using the Cleveland Clinic’s online risk-prediction model. They employed logistic regressions for diabetes mellitus type 2 and Cox proportional hazard regressions for cardiovascular diseases and colorectal cancers, respectively. They then increased the baseline risk estimate by comparing the relative risk of consuming processed and unprocessed meat.
The researchers calculated the preventable occurrences of type 2 diabetes, cardiovascular diseases, colorectal cancers, and deaths by comparing the incidences in baseline and interventional scenarios. The scenarios comprised 5.0%, 10.0%, 30.0%, 50.0%, 75.0%, and 100% decreases in the quantity (grams) ingested of processed, unprocessed, or both meat types.
The model was calibrated by dividing each individual’s ultimate illness risk by a calibration constant based on their demographic group. The researchers assessed the intervention’s effects across several demographic subgroups (age, gender, yearly family income, and ethnicity).
Results
The simulated sample size comprised 8,665 individuals, denoting 242,021,876 adult US residents. Among the 8,665 participants, 4,493 (52%) were females and 3,095 (36%) were non-Hispanic white; the average age was 50 years. At baseline, the weighted average daily processed meat intake was 29 grams, denoting a 30.0% decrease of 8.70 grams/day, and unprocessed meat was 47 grams, denoting a 30.0% decrease of 14 grams/day.
The analysis showed that reducing processed meat consumption by 30% might result in 352,900 fewer cases of type 2 diabetes, 92,500 fewer cases of cardiovascular diseases, 53,300 fewer cases of colorectal cancers, and 16,700 fewer deaths over the next ten years. Reducing the intake of unprocessed meat by 30% might result in 732,600 fewer cases of type 2 diabetes, 291,500 fewer cases of cardiovascular diseases, 32,200 fewer cases of colorectal cancers, and reduce death counts by 46,100 over ten years.
Lowering meat (processed or unprocessed) intake by 30% might result in 1,073,400 fewer cases of type 2 diabetes, 382,400 fewer cases of cardiovascular diseases, 84,400 fewer cases of colorectal cancers, and reduce death counts by 62,200 over ten years. After a 10-year 30% reduction in processed-type meat intake, the researchers estimated that individuals in households with an annual income of more than $25000 but less than $55000 who identified as non-Hispanic White, were male, and aged 18–49 years had the highest number of prevented occurrences of type 2 diabetes. Males had the highest number of prevented occurrences of colorectal cancer.
Conclusion
The study showed that lowering processed meat intake in the United States might lower health risks such as type 2 diabetes, cardiovascular disease, colorectal cancers, and mortality. According to the study, a 30% reduction in processed meat intake might avert 352,900 cases of type 2 diabetes, 92,500 cases of cardiovascular disease, 53,300 cases of colorectal cancer, and 16,700 all-cause deaths.
However, more study is needed to corroborate these findings and determine the influence of lowering processed and unprocessed meat consumption on micronutrient intake. The Dietary Guidelines for Americans should suggest minimizing processed meat intake.