Red and Processed Meat Consumption and Risk for All-Cause Mortality and Cardiometabolic Outcomes

Associations between meat consumption and all-cause and cause-specific mortality in middle-aged and older adults with frailty

OBJECTIVES

This study aimed to explore the associations between different types of meat consumption and mortality risk among people with frailty.

DESIGN

Longitudinal study.

SETTING AND PARTICIPANTS

We included 19,913 physically frail participants from the UK Biobank.

MEASUREMENTS

We used the validated brief food frequency questionnaire (FFQ) to measure meat consumption. Baseline diet data from 2006 to 2010 were collected, and participants were followed up until March 23, 2021. Cox proportional hazards regression models were conducted to examine the associations of meat consumption with mortality risk.

RESULTS

We identified 3,622 all-cause deaths, 1,453 cancer deaths, and 1,663 cardiovascular deaths during a median follow-up time of 11.2 years. Higher consumption of unprocessed poultry (per 25 g/day increment) was associated with a lower risk of all-cause mortality (hazard ratio [HR] 0.81, 95% confidence interval [CI] 0.75-0.88), cancer mortality (HR 0.84, 95% CI 0.74-0.96), and cardiovascular mortality (HR 0.72, 95% CI 0.63-0.81). Consumption of unprocessed red meat had a U-shaped relationship with mortality. Moderate consumption of unprocessed red meat 1.0-1.9 times/week was associated with a 14% (95% CI: 3 %-24%) lower risk of all-cause mortality than the lowest consumption frequency group (0-0.9 times/week). The hazard of cancer and CV mortality was also lower in the 1.0-1.9 times/week group, though the associations were not statistically significant. More frequent consumption of processed meat was associated with an increased risk of all-cause mortality (HR 1.20, 95% CI 1.07-1.34) and cardiovascular mortality (HR 1.20, 95% CI 1.02-1.42). Fish consumption was not associated with all types of mortality.

CONCLUSIONS

Higher consumption of processed meat, not fish, was associated with increased all-cause and cardiovascular mortality. In contrast, higher consumption of unprocessed poultry and moderate consumption of unprocessed red meat was associated with reduced all-cause, cancer, and cardiovascular mortality. These findings warrant further investigation to establish optimal dietary patterns for frail individuals.

Grilling the data: application of specification curve analysis to red meat and all-cause mortality

OBJECTIVES

To present an application of specification curve analysis-a novel analytic method that involves defining and implementing all plausible and valid analytic approaches for addressing a research question-to nutritional epidemiology.

STUDY DESIGN AND SETTING

We reviewed all observational studies addressing the effect of red meat on all-cause mortality, sourced from a published systematic review, and documented variations in analytic methods (eg, choice of model, covariates, etc.). We enumerated all defensible combinations of analytic choices to produce a comprehensive list of all the ways in which the data may reasonably be analyzed. We applied specification curve analysis to data from National Health and Nutrition Examination Survey 2007 to 2014 to investigate the effect of unprocessed red meat on all-cause mortality. The specification curve analysis used a random sample of all reasonable analytic specifications we sourced from primary studies.

RESULTS

Among 15 publications reporting on 24 cohorts included in the systematic review on red meat and all-cause mortality, we identified 70 unique analytic methods, each including different analytic models, covariates, and operationalizations of red meat (eg, continuous vs quantiles). We applied specification curve analysis to National Health and Nutrition Examination Survey, including 10,661 participants. Our specification curve analysis included 1208 unique analytic specifications, of which 435 (36.0%) yielded a hazard ratio equal to or more than 1 for the effect of red meat on all-cause mortality and 773 (64.0%) less than 1. The specification curve analysis yielded a median hazard ratio of 0.94 (interquartile range: 0.83-1.05). Forty-eight specifications (3.97%) were statistically significant, 40 of which indicated unprocessed red meat to reduce all-cause mortality and eight of which indicated red meat to increase mortality.

CONCLUSION

We show that the application of specification curve analysis to nutritional epidemiology is feasible and presents an innovative solution to analytic flexibility.

Red Meat Intake and the Risk of Cardiovascular Diseases: A Prospective Cohort Study in the Million Veteran Program

BACKGROUND

Red meat consumption was associated with an increased risk of cardiovascular disease (CVD) in prospective cohort studies and a profile of biomarkers favoring high CVD risk in short-term controlled trials. However, several recent systematic reviews and meta-analyses concluded with no or weak evidence for limiting red meat intake.

OBJECTIVES

To prospectively examine the associations between red meat intake and incident CVD in an ongoing cohort study with diverse socioeconomic and racial or ethnic backgrounds.

METHODS

Our study included 148,506 participants [17,804 female (12.0%)] who were free of cancer, diabetes, and CVD at baseline from the Million Veteran Program. A food frequency questionnaire measured red meat intakes at baseline. Nonfatal myocardial infarction and acute ischemic stroke were identified through a high-throughput phenotyping algorithm, and fatal CVD events were identified by searching the National Death Index.

RESULTS

Comparing the extreme categories of intake, the multivariate-adjusted relative risks of CVD was 1.18 (95% CI: 1.01, 1.38; P-trend < 0.0001) for total red meat, 1.14 (95% CI: 0.96, 1.36; P-trend = 0.01) for unprocessed red meat, and 1.29 (95% CI: 1.04, 1.60; P-trend = 0.003) for processed red meat. We observed a more pronounced positive association between red meat intake and CVD in African American participants than in White participants (P-interaction = 0.01). Replacing 0.5 servings/d of red meat with 0.5 servings/d of nuts, whole grains, and skimmed milk was associated with 14% (RR: 0.86; 95% CI: 0.83, 0.90), 7% (RR: 0.93; 95% CI: 0.89, 0.96), and 4% (RR: 0.96; 95% CI: 0.94, 0.99) lower risks of CVD, respectively.

CONCLUSIONS

Red meat consumption is associated with an increased risk of CVD. Our findings support lowering red meat intake and replacing red meat with plant-based protein sources or low-fat dairy foods as a key dietary recommendation for the prevention of CVD.

The Role of Methionine-Rich Diet in Unhealthy Cerebrovascular and Brain Aging: Mechanisms and Implications for Cognitive Impairment

As aging societies in the western world face a growing prevalence of vascular cognitive impairment and Alzheimer's disease (AD), understanding their underlying causes and associated risk factors becomes increasingly critical. A salient concern in the western dietary context is the high consumption of methionine-rich foods such as red meat. The present review delves into the impact of this methionine-heavy diet and the resultant hyperhomocysteinemia on accelerated cerebrovascular and brain aging, emphasizing their potential roles in cognitive impairment. Through a comprehensive exploration of existing evidence, a link between high methionine intake and hyperhomocysteinemia and oxidative stress, mitochondrial dysfunction, inflammation, and accelerated epigenetic aging is drawn. Moreover, the microvascular determinants of cognitive deterioration, including endothelial dysfunction, reduced cerebral blood flow, microvascular rarefaction, impaired neurovascular coupling, and blood-brain barrier (BBB) disruption, are explored. The mechanisms by which excessive methionine consumption and hyperhomocysteinemia might drive cerebromicrovascular and brain aging processes are elucidated. By presenting an intricate understanding of the relationships among methionine-rich diets, hyperhomocysteinemia, cerebrovascular and brain aging, and cognitive impairment, avenues for future research and potential therapeutic interventions are suggested.

White rice consumption and risk of cardiometabolic and cancer outcomes: A systematic review and dose-response meta-analysis of prospective cohort studies

White rice is the food more than half of the world's population depends on. White rice intake can significantly increase the glycemic load of consumers and bring some adverse health effects. However, the quality of evidence implicating white rice in adverse health outcomes remains unclear. To evaluate the association between white rice consumption and the risk of cardiometabolic and cancer outcomes, a systematic review and dose-response meta-analysis of the relevant publications were performed. Twenty-three articles including 28 unique prospective cohorts with 1,527,198 participants proved eligible after a comprehensive search in four databases. For the risk of type 2 diabetes mellitus (T2DM), the pooled RR was 1.18 (16 more per 1000 persons) for comparing the highest with the lowest category of white rice intake, with moderate certainty evidence. Females presented a higher risk (23 more per 1000 persons) in subgroup analysis. And every additional 150 grams of white rice intake per day was associated with a 6% greater risk of T2DM (5 more per 1000 persons) with a linear positive trend. We found no significant associations between white rice intake and risk of cardiovascular diseases (CVD), CVD mortality, cancer, and metabolic syndrome. In conclusion, moderate certainty evidence demonstrated that white rice intake was associated with T2DM risk, with a linear positive trend. However, low to very low certainty of evidence suggested that no substantial associations were found between white rice intake and other cardiometabolic and cancer outcomes. More cohorts are needed to strength the evidence body.

Evidence on the potential effects of halal meat on sleep/wake cycles and mood state profile: A pilot study

Nowadays, halal meat is attracting consumers as a healthier product. However, little is known about its nutritional content and possible health effects. A comparative analysis of the protein and amino acid contents between halal and non-halal meats (beef and lamb) was carried out in the present work. Additionally, a pilot study was also simultaneously performed to analyse the impact of their consumption on sleep/wake cycles and mood state profile in general population. Participants (n = 25) were asked to exclusively consume halal meats (1,000 g of gross weight/week) for 30 days. Objective and subjective sleep qualities, mood state profile, and levels of the urinary metabolites of serotonin and melatonin were assessed at baseline and post-intervention. Significantly higher contents of proteins and some amino acids were observed in halal-lamb and halal-beef, respectively. The consumption of halal meats for 30 days caused a slight improvement in men’s diurnal activity and mood state profile, as well as in women’s subjective sleep quality. Significantly higher urine levels of serotonin were also reported, particularly in men. Halal meat consumption seems to have a positive impact on sleep/wake cycles and mood state profile, likely due to the higher protein and amino acid contents. Additional scientific research is needed to support consumer trends in the coming years.

Myoglobin diet affected colonic mucus layer and barrier by increasing the abundance of several beneficial gut bacteria

The study aimed to explore the in vitro digestion of myoglobin diet and its relationship with the gut microbiota and intestinal barrier at two feeding time points. In vitro study...

Critical overview of the use of plant antioxidants in the meat industry: Opportunities, innovative applications and future perspectives

The number of articles devoted to study the effect of "natural antioxidants" on meat systems has remarkably increased in the last 10 years. Yet, a critical review of literature reveals recurrent flaws in regards to the rationale of the application, the experimental design, the characterisation of the plant sources, the discussion of the molecular mechanisms and of the potential benefits. The selection of the appropriate source of these antioxidants and the identification of their bioactive constituents, are essential to understand their mode of action and set effective and safe doses. The methodological approach should also be planned with care as the recorded effects and main conclusions largely depend on the accuracy and specificity of the methods. This article aims to critically review the recent advances in the application of plant antioxidants in meat and meat products and briefly covers current trends of innovative application and future trends.

Association of soft drink and 100% fruit juice consumption with all-cause mortality, cardiovascular diseases mortality, and cancer mortality: A systematic review and dose-response meta-analysis of prospective cohort studies

Sugar-sweetened beverages (SSBs), artificially sweetened beverages (ASBs), and 100% fruit juices are frequently consumed and have been documented that they could lead to serious disease burden. However, inconsistent evidence on the association between SSBs, ASBs, and 100% fruit juices consumption and mortality have been presented. PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and PsycINFO were systematically searched. We conducted a random-effects meta-analysis and dose-response meta-analysis to assess the association and calculated the pooled hazard ratio with 95% confidence interval. And we evaluated the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Thirteen studies with 1,539,127 participants proved eligible. An SSB-consumption increase per 250 mL/day was associated with a 4% greater risk of all-cause mortality (5 more per 1000 persons; low certainty) and 8% greater risk of cardiovascular disease mortality (3 more per 1000 persons; low certainty). ASB-consumption increase per 250 mL/day demonstrated a 4% greater risk of all-cause mortality (5 more per 1000 persons; low certainty) and 4% greater risk of cardiovascular disease mortality (2 more per 1000 persons; low certainty). The association of SSBs and ASBs with cancer mortality was not significant, with a very low certainty of evidence. There was evidence of a linear dose-response association between SSB intake and cancer mortality, as well as between ASB intake and all-cause mortality and cancer mortality. We observed a non-linear dose-response association between ASB intake and CVD mortality and SSB intake and all-cause and CVD mortality. Low certainty of evidence demonstrated that per 250 mL/day consumption increase in SSBs and ASBs had a small impact on all-cause and cardiovascular disease mortality but not on cancer mortality. The association of 100% fruit juice consumption with all-cause and cardiovascular disease mortality was uncertain.

The Future of Meat: Health Impact Assessment with Randomized Evidence

Massive animal farming for meat production poses major problems in terms of resource use, environmental impact, and biodiversity. Furthermore, excessive meat consumption has been associated with multiple deleterious health consequences. However, more and better-designed randomized trials are needed to increase the level of evidence on the health impacts of meat. Novel meat alternatives, such as plant- and cell-based meat, are much less impactful to the environment and might replace traditional animal meat in the future, but, despite promising early data, the health consequences of these novel products need further study. This manuscript focuses on the health impacts of meat over 3 main sections: 1) overview of the evidence highlighting the association of meat consumption with health; 2) novel alternatives to meat, including plant-based and cell-based alternatives; and 3) examine the rationale for randomized studies to evaluate the effects of the novel meat alternatives compared with the standard animal meat.

Association of food expenditure with life expectancy in the United States, 2001-2014

OBJECTIVES

A healthy diet is associated with reduced risk for premature death; however, data on the association between food expenditure and life expectancy are scarce. The aim of this study was to determine the association of expenditure on food groups with life expectancy in men and women.

METHODS

This study used data from 1548 counties, representing >90% of the population of the United States from 2001 through the end of 2014. Multivariable adjusted Bayesian generalized linear models were used to assess the association of county-level expenditure on nine groups of individual food and combined healthy and unhealthy foods, and a constructed healthy diet score with life expectancy at 40 y of age by sex.

RESULTS

A 1-unit increase in the healthy diet score based on food expenditure was associated with a 0.07 y (95% confidence interval [CI], 0.05-0.10), 0.04 y (95% CI, 0.02-0.07), and 0.06 y (95% CI, 0.04-0.08) increase in county-level life expectancy among men alone, women alone, and men and women combined, respectively. Increasing expenditure on whole grains (estimate of per 1% increase 0.07; 95% CI, 0.03-0.11), fresh fruit and vegetables (0.06; 95% CI, 0.02-0.09), and dairy products (0.05; 95% CI, 0.03-0.07), as well as reducing expenditure on sugar-sweetened beverages (-0.02; 95% CI, -0.04 to -0.01) and processed red meat (-0.05; 95% CI, -0.08 to -0.02) showed a positive association with increased county-level life expectancy.

CONCLUSIONS

These findings may inform a nutritional measure against premature death and stagnation of increase in life expectancy.

Characteristics and quality of systematic reviews and meta-analyses of observational nutritional epidemiology: a cross-sectional study

BACKGROUND

Dietary recommendations and policies should be guided by rigorous systematic reviews. Reviews that are of poor methodological quality may be ineffective or misleading. Most of the evidence in nutrition comes from nonrandomized studies of nutritional exposures (usually referred to as nutritional epidemiology studies), but to date methodological evaluations of the quality of systematic reviews of such studies have been sparse and inconsistent.

OBJECTIVES

We aimed to investigate the quality of recently published systematic reviews and meta-analyses of nutritional epidemiology studies and to propose guidance addressing major limitations.

METHODS

We searched MEDLINE (January 2018-August 2019), EMBASE (January 2018-August 2019), and the Cochrane Database of Systematic Reviews (January 2018-February 2019) for systematic reviews of nutritional epidemiology studies. We included a random sample of 150 reviews.

RESULTS

Most reviews were published by authors from Asia (n = 49; 32.7%) or Europe (n = 43; 28.7%) and investigated foods or beverages (n = 60; 40.0%) and cancer morbidity and mortality (n = 54; 36%). Reviews often had important limitations: less than one-quarter (n = 30; 20.0%) reported preregistration of a protocol and almost one-third (n = 42; 28.0%) did not report a replicable search strategy. Suboptimal practices and errors in the synthesis of results were common: one-quarter of meta-analyses (n = 30; 26.1%) selected the meta-analytic model based on statistical indicators of heterogeneity and almost half of meta-analyses (n = 50; 43.5%) did not consider dose-response associations even when it was appropriate to do so. Only 16 (10.7%) reviews used an established system to evaluate the certainty of evidence.

CONCLUSIONS

Systematic reviews of nutritional epidemiology studies often have serious limitations. Authors can improve future reviews by involving statisticians, methodologists, and researchers with substantive knowledge in the specific area of nutrition being studied and using a rigorous and transparent system to evaluate the certainty of evidence.