Substituting Lean Beef for Carbohydrate in a Healthy Dietary Pattern Does Not Adversely Affect the Cardiometabolic Risk Factor Profile in Men and Women at Risk for Type 2 Diabetes

Industry study sponsorship and conflicts of interest on the effect of unprocessed red meat on cardiovascular disease risk: a systematic review of clinical trials

BACKGROUND

Experimental research on the link between unprocessed red meat and cardiovascular disease risk is inconsistent and may differ according to the financial interests of red meat industry sponsors.

OBJECTIVES

This study aims to assess whether studies sponsorship or conflicts of interest with the red meat industry are associated with reported outcomes of unprocessed red meat consumption effect on risk factors for cardiovascular disease.

METHODS

PubMed, Cochrane Library, and Scopus were searched from the inception of the databases to 3 March 2024. Studies were classified as "Red meat industry-related" if any of the authors declared affiliation or financial disclosure indicating a link to the red meat industry; or "Red Meat industry-independent." Reported outcomes were independently graded as favorable, neutral, or unfavorable. Studies were also categorized by type of control group. The quality of evidence for each outcome was evaluated using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

A total of 44 studies were included, of which 66% had a link to the red meat industry. All independent studies reported either unfavorable (73.3%) or neutral (26.7%) cardiovascular outcomes when consuming unprocessed red meat. Conversely, all studies related to the red meat industry reported either favorable (20.7%) or neutral (79.3%) cardiovascular outcomes for red meat intake. A total of 69.6% of trials (16 of 23) showed a neutral effect of unprocessed red meat compared with other animal proteins, whereas 70% (7 of 10) reported an unfavorable effect compared with plant proteins. Studies with conflicts of interest were nearly 4 times more likely to report "Favorable/Neutral" outcomes compared with independent studies (odds ratio 3.75, 95% confidence interval: 1.62, 8.67).

CONCLUSIONS

Our findings highlight that using animal protein as a comparator in industry-funded studies, with quality of evidence rated as very low to low, may underestimate the cardiovascular benefits of reducing red meat intake. Most studies without conflicts of interest with the red meat industry suggested an unfavorable effect of unprocessed red meat consumption on risk factors for cardiovascular disease.

TRIAL REGISTRATION NUMBER

This trial for systematic reviews or meta-analyses was registered at PROSPERO as CRD42024525197 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=525197).

Beef Consumption and Cardiovascular Disease Risk Factors: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Background

Results from observational studies suggest associations of red meat intake with increased risk of cardiovascular disease (CVD); however, RCTs have not clearly demonstrated a link between red meat consumption and CVD risk factors. Further, the specific effects of beef, the most consumed red meat in the United States, have not been extensively investigated.

Objectives

This study aimed to perform a systematic review and meta-analysis of RCT data evaluating the effects of minimally or unprocessed beef intake on CVD risk factors in adults.

Methods

A search of the literature was conducted using PubMed and CENTRAL databases. RCTs in adults that provided diets with fresh or minimally processed beef were included. Data were extracted, and pooled estimates from random-effects models were expressed as standardized mean differences (SMDs) between the beef intervention and comparator intervention with less or no beef. Sensitivity and subgroup analyses were also performed.

Results

Twenty relevant RCTs that met the criteria were included. Beef intake did not impact blood pressure or most lipoprotein-related variables, including total cholesterol, HDL-cholesterol, triglycerides, non-HDL-cholesterol, apolipoprotein A or B, and VLDL-cholesterol. Beef consumption had a small but significant effect on LDL-cholesterol (0.11; 95% CI: 0.008, 0.20; P = 0.03), corresponding to ∼2.7 mg/dL higher LDL-cholesterol in diets containing more beef than that in low-beef or -o beef comparator diets. Sensitivity analyses show this effect was lost when 1 influential study was removed.

Conclusions

Daily unprocessed beef intake do not significantly affect most blood lipids, apolipoproteins, or blood pressures, except for a small increase in LDL-cholesterol compared with diets with less or no beef. Thus, there may be other factors influencing the association of red meat and beef on CVD risk that deserve further investigation.This study was registered at INPLASY as 202420013.

Estimated effects of reductions in processed meat consumption and unprocessed red meat consumption on occurrences of type 2 diabetes, cardiovascular disease, colorectal cancer, and mortality in the USA: a microsimulation study

BACKGROUND

High consumption of processed meat and unprocessed red meat is associated with increased risk of multiple chronic diseases, although there is substantial uncertainty regarding the relationship for unprocessed red meat. We developed a microsimulation model to estimate how reductions in processed meat and unprocessed red meat consumption could affect rates of type 2 diabetes, cardiovascular disease, colorectal cancer, and mortality in the US adult population.

METHODS

We used data from two versions of the US National Health and Nutrition Examination Survey, one conducted during 2015-16 and one conducted during 2017-18, to create a simulated US population. The starting cohort was restricted to respondents aged 18 years or older who were not pregnant and had 2 days of dietary-recall data. First, we used previously developed risk models to estimate the baseline disease risk of an individual. For type 2 diabetes we used a logistic-regression model and for cardiovascular disease and colorectal cancer we used Cox proportional-hazard models. We then multiplied baseline risk by relative risk associated with individual processed meat and unprocessed red meat consumption. Prevented occurrences of type 2 diabetes, cardiovascular disease, colorectal cancer, and mortality were computed by taking the difference between the incidence in the baseline and intervention scenarios. All stages were repeated for ten iterations to correspond to a 10-year time span. Scenarios were reductions of 5%, 10%, 30%, 50%, 75%, and 100% in grams consumed of processed meat, unprocessed red meat, or both. Each scenario was repeated 50 times for uncertainty analysis.

FINDINGS

The total number of individual respondents included in the simulated population was 8665, representing 242 021 876 US adults. 4493 (51·9%) of 8665 individuals were female and 4172 (48·1%) were male; mean age was 49·54 years (SD 18·38). At baseline, weighted mean daily consumption of processed meat was 29·1 g, with a 30% reduction being 8·7 g per day, and of unprocessed red meat was 46·7 g, with a 30% reduction being 14·0 g per day. We estimated that a 30% reduction in processed meat intake alone could lead to 352 900 (95% uncertainty interval 345 500-359 900) fewer occurrences of type 2 diabetes, 92 500 (85 600-99 900) fewer occurrences of cardiovascular disease, 53 300 (51 400-55 000) fewer occurrences of colorectal cancer, and 16 700 (15 300-17 700) fewer all-cause deaths during the 10-year period. A 30% reduction in unprocessed red meat intake alone could lead to 732 600 (725 700-740 400) fewer occurrences of type 2 diabetes, 291 500 (283 900-298 800) fewer occurrences of cardiovascular disease, 32 200 (31 500-32 700) fewer occurrences of colorectal cancer, and 46 100 (45 300-47 200) fewer all-cause deaths during the 10-year period. A 30% reduction in both processed meat and unprocessed red meat intake could lead to 1 073 400 (1 060 100-1 084 700) fewer occurrences of type 2 diabetes, 382 400 (372 100-391 000) fewer occurrences of cardiovascular disease, 84 400 (82 100-86 200) fewer occurrences of colorectal cancer, and 62 200 (60 600-64 400) fewer all-cause deaths during the 10-year period.

INTERPRETATION

Reductions in processed meat consumption could reduce the burden of some chronic diseases in the USA. However, more research is needed to increase certainty in the estimated effects of reducing unprocessed red meat consumption.

FUNDING

The Wellcome Trust.

Higher Expression of miR-15b-5p with Inclusion of Fresh, Lean Beef as Part of a Healthy Dietary Pattern Is Inversely Associated with Markers of Cardiometabolic Disease Risk

BACKGROUND

Considerable controversy exists surrounding the consumption of red meat and its impacts on cardiometabolic health and if it may further impact risk factors at the molecular level.

OBJECTIVE

The purpose of this study was to examine the acute effects of dietary patterns, varying in red meat quantity, on the expression of circulating microRNAs (miRNAs), which are emerging biomarkers of metabolic dysfunction and chronic disease severity.

METHODS

Secondary analyses were performed on plasma samples collected within a randomized, crossover design study in 16 women with overweight (mean ± standard deviation, age = 33 ± 9.89 y; body mass index = 27.9 ± 1.66 kg/m2). Participants were provided with eucaloric, isonitrogenous diets (15% of daily intake as protein) containing either 2 servings of fresh, lean beef/day (BEEF) or 0 servings of fresh, lean beef/day (PLANT) for 7 d/pattern. Fasting blood samples were collected at the end of each dietary pattern for the assessment of 12 circulating metabolic miRNA expression levels (determined a priori by quantitative reverse transcriptase-polymerase chain reaction), plasma glucose, insulin, interleukin-6, tumor necrosis factor-α, C-reactive protein (CRP), adiponectin, glucagon-like peptide-1, and branched-chain amino acids.

RESULTS

Of the 12 miRNAs, miR-15b-5p expression was higher following BEEF versus PLANT (P = 0.024). Increased miR-15b-5p expression correlated with decreased fasting CRP (r = -0.494; P = 0.086) and insulin concentrations (r = -0.670; P = 0.017). miR-15b-5p was inversely correlated with insulin resistance (r = -0.642; P = 0.024) and β cell function (r = -0.646; P = 0.023) and positively correlated with markers of insulin sensitivity (r = 0.520; P = 0.083). However, the correlations were only observed following BEEF, not PLANT.

CONCLUSIONS

These data indicate that the short-term intake of fresh, lean beef as part of a healthy dietary pattern impacts potential biomarkers of cardiometabolic health that are associated with cardiometabolic risk factors in women with overweight. This study was registered at clinicaltrials.gov as NCT02614729.

Consumption of red, white, and processed meat and odds of developing kidney damage and diabetic nephropathy (DN) in women: a case control study

Diabetic nephropathy (DN) is one of the most prevalent and severe complications of diabetes mellitus (DM) and is associated with increased morbidity and mortality. We aimed to investigate the associations between red, processed, and white meat consumption and the odds of developing kidney damage and DN in women. We enrolled 105 eligible women with DN and 105 controls (30-65 years). A validated and reliable food frequency questionnaire (FFQ) was used to evaluate the consumption of red, processed, and white meat. Biochemical variables and anthropometric measurements were assessed for all patients using pre-defined protocols. Binary logistic regression was conducted to examine possible associations. The results of the present study showed that there was a direct significant association between high consumption of red meat and processed meats and odds of microalbuminuria (red meat 2.30, 95% CI 1.25, 4.22; P-value = 0.007, processed meat: OR 2.16, 95% CI 1.18, 3.95; P-value = 0.01), severe albuminuria (red meat OR 3.25, 95% CI 1.38, 7.46; P-value = 0.007, processed meat: OR 2.35, 95% CI 1.01, 5.49; P-value = 0.04), BUN levels (red meat: OR 2.56, 95% CI 1.10, 5.93; P-value = 0.02, processed meat: OR 2.42, 95% CI 1.04, 5.62; P-value = 0.03), and DN (red meat 2.53, 95% CI 1.45, 4.42; P-value = 0.001, processed meat: OR 2.21; 95% CI 1.27, 3.85; P-value = 0.005). In summary, our study suggests that higher consumption of red and processed meat sources may be associated with microalbuminuria, severe albuminuria, higher BUN level, and higher odds of DN.

Changes in Choline Metabolites and Ceramides in Response to a DASH-Style Diet in Older Adults

This feeding trial evaluated the impact of the Dietary Approaches to Stop Hypertension diet on changes in plasma choline, choline metabolites, and ceramides in obese older adults; 28 adults consumed 3oz (n = 15) or 6oz (n = 13) of beef within a standardized DASH diet for 12 weeks. Plasma choline, betaine, methionine, dimethylglycine (DMG), phosphatidylcholine (PC), lysophosphotidylcholine (LPC), sphingomyelin, trimethylamine-N-oxide (TMAO), L-carnitine, ceramide, and triglycerides were measured in fasted blood samples. Plasma LPC, sphingomyelin, and ceramide species were also quantified. In response to the study diet, with beef intake groups combined, plasma choline decreased by 9.6% (p = 0.012); DMG decreased by 10% (p = 0.042); PC decreased by 51% (p < 0.001); total LPC increased by 281% (p < 0.001); TMAO increased by 26.5% (p < 0.001); total ceramide decreased by 22.1% (p < 0.001); and triglycerides decreased by 18% (p = 0.021). All 20 LPC species measured increased (p < 0.01) with LPC 16:0 having the greatest response. Sphingomyelin 16:0, 18:0, and 18:1 increased (all p < 0.001) by 10.4%, 22.5%, and 24%, respectively. In contrast, we observed that sphingomyelin 24:0 significantly decreased by 10%. Ceramide 22:0 and 24:0 decreased by 27.6% and 10.9% (p < 0.001), respectively, and ceramide 24:1 increased by 36.8% (p = 0.013). Changes in choline and choline metabolites were in association with anthropometric and cardiometabolic outcomes. These findings show the impact of the DASH diet on choline metabolism in older adults and demonstrate the influence of diet to modify circulating LPC, sphingomyelin, and ceramide species.

Red meat consumption and risk factors for type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVES

Results from observational studies suggest an association of red meat intake with risk of type 2 diabetes mellitus (T2D). However, results from randomized controlled trials (RCTs) have not clearly supported a mechanistic link between red meat intake and T2D risk factors. Therefore, a systematic review and meta-analysis were conducted on RCTs evaluating the effects of diets containing red meat (beef, pork, lamb, etc.), compared to diets with lower or no red meat, on markers of glucose homeostasis in adults.

METHODS

A search of PubMed and CENTRAL yielded 21 relevant RCTs. Pooled estimates were expressed as standardized mean differences (SMDs) between the red meat intervention and the comparator intervention with less or no red meat.

RESULTS

Compared to diets with reduced or no red meat intake, there was no significant impact of red meat intake on insulin sensitivity (SMD: -0.11; 95% CI: -0.39, 0.16), insulin resistance (SMD: 0.11; 95% CI: -0.24, 0.45), fasting glucose (SMD: 0.13; 95% CI: -0.04, 0.29), fasting insulin (SMD: 0.08; 95% CI: -0.16, 0.32), glycated hemoglobin (HbA1c; SMD: 0.10; 95% CI: -0.37, 0.58), pancreatic beta-cell function (SMD: -0.13; 95% CI: -0.37, 0.10), or glucagon-like peptide-1 (GLP-1; SMD: 0.10; 95% CI: -0.37, 0.58). Red meat intake modestly reduced postprandial glucose (SMD: -0.44; 95% CI: -0.67, -0.22; P < 0.001) compared to meals with reduced or no red meat intake. The quality of evidence was low to moderate for all outcomes.

CONCLUSIONS

The results of this meta-analysis suggest red meat intake does not impact most glycemic and insulinemic risk factors for T2D. Further investigations are needed on other markers of glucose homeostasis to better understand whether a causal relationship exists between red meat intake and risk of T2D.

PROSPERO REGISTRATION

CRD42020176059.

Cardiovascular disease prevention and management in the COVID-19 era and beyond: An international perspective

Despite some indicators of a localized curtailing of cardiovascular disease (CVD) prevalence, CVD remains one of the largest contributors to global morbidity and mortality. While the magnitude and impact of the coronavirus disease 2019 (COVID-19) pandemic have yet to be realized in its entirety, an unquestionable impact on global health and well-being is already clear. At a time when the global state of CVD is perilous, we provide a continental overview of prevalence data and initiatives that have positively influenced CVD outcomes. What is clear is that despite attempts to address the global burden of CVD, there remains a lack of collective thinking and approaches. Moving forward, a coordinated global infrastructure that, if developed with appropriate and relevant key stakeholders, could provide significant and longstanding benefits to public health and yield prominent and consistent policy resulting in impactful change. To achieve global impact, research priorities that address multi-disciplinary social, environmental, and clinical perspectives must be underpinned by unified approaches that maximize public health.

The whole food beef matrix is more than the sum of its parts

Foods are not simply a delivery vehicle for nutrients; they consist of a matrix in which nutrients and non-nutrient compounds are presented that induce physiologic effects different from isolated nutrients. Dietary guidance is often based on effects of single nutrients that are considered unhealthy, such as saturated fat in beef. The purpose of this paper is to propose a working definition of the whole food beef matrix whose consumption has health effects distinct from those of isolated nutrients. The beef matrix can be defined as: the collective nutritive and non-nutritive components of the beef food structure and their unique chemical and physical interactions that may be important for human health which are distinguishable from those of the single components in isolation. Background information supporting this approach is summarized on multiple components provided by beef, temporal changes in beef consumption, dietary guidance that restricts beef, and how the background diet determines healthfulness rather than a single food. Examples of research are provided on other whole foods that differ from their constitutive nutrients and lay the groundwork for studies of beef as part of a healthy dietary pattern.

The effect of TCF7L2 polymorphisms on inflammatory markers after 16 weeks of legume-based dietary approach to stop hypertension (DASH) diet versus a standard DASH diet: a randomised controlled trial

Backgrounds

This randomized controlled trial aimed to investigate the effects of replacing red meat with legumes in the dietary approach to stop hypertension (DASH) diet on inflammatory markers over 16 weeks in overweight and obese individuals with type 2 diabetes. Also, the modulatory effects of TCF7L2 rs7903146 variant on this effect were assessed.

Methods

In this trial, 300 participants with type 2 diabetes, aged 30–65 years with an identified TCF7L2 rs7903146 genotype, were studied. The participants were randomly assigned to the DASH diet or the legume-based DASH diet over 16 weeks. In the DASH diet group, the participants were instructed to follow the standard DASH diet. The legume-based DASH diet was similar to the standard DASH diet, with the exception that one serving of red meat was replaced with one serving of legumes at least five days a week. At the beginning of the study and 16-week follow-up, venous blood samples were collected from all participants who fasted for 12–14 h overnight. The serum concentration of High-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) was measured using an enzyme-linked immunosorbent assay (ELISA) kit. Also, the serum malondialdehyde (MDA) concentration was assessed based on a colorimetric method using a commercial kit. The primary outcome was the difference in hs-CRP changes between the diets. A secondary outcomes was the difference in IL-6, TNF-α, and MDA between the groups among total population and based on TCF7L2 rs7903146 risk allele (CT + TT) and non-risk allele (CC) separately.

Results

The hs-CRP level reduced in the legume-based DASH diet group as compared to the DASH diet group in the 16-week follow-up group. The levels of TNF-α, IL-6, and MDA reduced after the legume-based DASH diet relative to the DASH diet. Reduction of inflammatory markers was observed in both carriers of rs7903146 risk allele and non-risk allele.

Conclusions

Substituting one serving of red meat with one serving of legumes in DASH diet, at least five days a week, could improve the hs-CRP, TNF-α, IL-6, and MDA in participants with type 2 diabetes regardless of having rs7903146 risk or non-risk allele.

Trial registration IRCT, IRCT20090203001640N17.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00671-7.

Dietary Influences on Atherosclerotic Cardiovascular Disease Risk

PURPOSEOF REVIEW

Professional organizations recommend various healthy dietary patterns for atherosclerotic vascular disease (ASCVD) prevention. The purpose of this review is to discuss the evidence for the recommended healthy dietary patterns and ASCVD risk reduction, as well as briefly review specific areas of controversy.

RECENT FINDINGS

The Mediterranean, Dietary Approach to Stop Hypertension, and plant-based dietary patterns have been associated with lower ASCVD risk in observational studies. The Mediterranean dietary pattern has been demonstrated to reduce ASCVD event risk in a large, randomized, controlled trial. Observational studies demonstrate dietary patterns with higher quality foods are associated with decreased ASCVD risk and mortality. Healthy dietary patterns emphasize higher intakes of plant-based foods, lean animal protein sources, and non-tropical oils, while limiting intakes of sugar-sweetened products, refined grains, and processed meats. Encouraging individuals to consume healthy dietary patterns with high-quality foods can promote ASCVD prevention and overall health.

Effect of varying quantities of lean beef as part of a Mediterranean-style dietary pattern on lipids and lipoproteins: a randomized crossover controlled feeding trial

BACKGROUND

It remains unclear whether red meat consumption is causatively associated with cardiovascular disease (CVD) risk, and few randomized controlled studies have examined the effect of incorporating lean beef into a healthy dietary pattern.

OBJECTIVES

To evaluate the effects of a Mediterranean (MED) diet (carbohydrate 42%, protein 17%, fat 41%, SFAs 8%, MUFAs 26%, PUFAs 8%) with 14 (MED0.5; 0.5 oz), 71 (MED2.5; 2.5 oz), and 156 (MED5.5; 5.5 oz) g/d/2000 kcal lean beef compared with an average American diet (AAD; carbohydrate 52%, protein 15%, fat 33%, SFAs 12%, MUFAs 13%, PUFAs 8%) on lipid and lipoprotein concentrations, particle number, and size.

METHODS

This was a multicenter, 4-period controlled feeding, randomized crossover study. Fifty-nine generally healthy males and females (BMI 20-38 kg/m2; age 30-65 y) consumed each diet for 4 wk with a ≥1-wk washout between the diets. Fasting blood samples were collected at baseline and at the end of each 4-wk period. Lipid subfractions were measured by NMR.

RESULTS

Compared with the AAD, all 3 MED diets decreased LDL cholesterol (MED0.5: -10.3 mg/dL; 95% CI: -5.4, -15.7 mg/dL; MED2.5: -9.1 mg/dL; 95% CI: -3.9, -14.3 mg/dL; MED5.5: -6.9 mg/dL; 95% CI: -1.7, -12.1 mg/dL; P < 0.0001). All MED diets elicited similar reductions in total LDL particle number compared with baseline (P < 0.005); however, significant decreases only occurred with MED0.5 (-91.2 nmol/L; 95% CI: -31.4, -151.0 nmol/L) and MED2.5 (-85.3 nmol/L; 95% CI: -25.4, -145.2 nmol/L) compared with AAD (P < 0.003). Compared with the AAD, non-HDL cholesterol (P < 0.01) and apoB (P < 0.01) were lower following the 3 MED diets; there were no differences between the MED diets. All diets reduced HDL-cholesterol and HDL particle number from baseline (P < 0.01).

CONCLUSIONS

Lipid and lipoprotein lowering was not attenuated with the inclusion of lean beef in amounts ≤71 g (2.5 oz)/d as part of a healthy low-saturated-fat Mediterranean-style diet.This study is registered at clinicaltrials.gov as NCT02723617.

Top 10 dietary strategies for atherosclerotic cardiovascular risk reduction

Poor dietary quality has surpassed all other mortality risk factors, accounting for 11 million deaths and half of CVD deaths globally. Implementation of current nutrition recommendations from the American Heart Association (AHA), American College of Cardiology (ACC) and the National Lipid Association (NLA) can markedly benefit the primary and secondary prevention of atherosclerotic cardiovascular disease (ASCVD). These include: 1) incorporate nutrition screening into medical visits; 2) refer patients to a registered dietitian nutritionist (RDN) for medical nutrition therapy, when appropriate, for prevention of ASCVD; 3) follow ACC/AHA Nutrition and Diet Recommendations for ASCVD prevention and management of overweight/obesity, type 2 diabetes and hypertension; 4) include NLA nutrition goals for optimizing low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) and reducing ASCVD risk; 5) utilize evidence-based heart-healthy eating patterns for improving cardiometabolic risk factors, dyslipidemia and ASCVD risk; 6) implement ACC/AHA/NLA nutrition and lifestyle recommendations for optimizing triglyceride levels; 7) understand the impact of saturated fats, trans fats, omega-3 and omega-6 polyunsaturated fats and monounsaturated fats on ASCVD risk; 8) limit excessive intake of dietary cholesterol for those with dyslipidemia, diabetes and at risk for heart failure; 9) include dietary adjuncts such as viscous fiber, plant sterols/stanols and probiotics; and 10) implement AHA/ACC and NLA physical activity recommendations for the optimization of lipids and prevention of ASCVD. Evidence on controversies pertaining to saturated fat, processed meat, red meat, intermittent fasting, low-carbohydrate/very-low-carbohydrate diets and caffeine are discussed.