A meta-analysis of randomized controlled trials that compare the lipid effects of beef versus poultry and/or fish consumption

Healthy Dietary Patterns with and without Meat Improved Cardiometabolic Disease Risk Factors in Adults: A Randomized Crossover Controlled Feeding Trial

We assessed the effects of consuming a U.S.-style healthy dietary pattern (HDP) with lean, unprocessed beef (BEEF) compared to a U.S.-style HDP without meat (vegetarian, VEG) on short-term changes in cardiometabolic disease (CMD) risk factors in adults classified as overweight or obese. Forty-one adults (22 females, 19 males; age 39.9 ± 8.0 y; BMI 29.6 ± 3.3 kg/m2; mean ± SD) completed two 5-week controlled feeding periods (randomized, crossover, controlled trial). For the BEEF HDP, two 3-oz (168-g) servings/d of lean, unprocessed beef were predominately substituted for some starchy vegetables and refined grains in the VEG HDP. Baseline and post-intervention measurements were fasting CMD risk factors, with serum low-density lipoprotein (LDL), total cholesterol (TC), and total apolipoprotein B as primary outcomes. VEG reduced LDL, insulin, and glucose compared to BEEF. Reductions did not differ between VEG vs. BEEF for TC, high-density lipoprotein (HDL), apolipoprotein A1, small, dense LDL IV, buoyant HDL2b, TC-to-HDL ratio, and systolic blood pressure. Total apolipoprotein B and all other CMD risk factors measured were not influenced by HDP type nor changed over time. Adopting a U.S.-style HDP that is either vegetarian or omnivorous with beef improved multiple cardiometabolic disease risk factors among adults classified as overweight or obese.

The association between meat intake and the risk of coronary heart disease in Korean men using the Framingham risk score: A prospective cohort study

BACKGROUND AND AIMS

Research suggests that meat intake may increase the risk of coronary heart disease (CHD), but most studies take place in Western countries, where the types and amount of meat products consumed differ from those in Asian countries. We aimed to identify the association between meat intake and CHD risk in Korean male adults, using the Framingham risk score.

METHODS AND RESULTS

We used data from the Korean Genome and Epidemiology Study (KoGES) Health Examinees (HEXA) study, including 13,293 Korean male adults. We estimated the association of meat intake with ≥20% 10-year CHD risk using Cox proportional hazards regression models to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs). Subjects with the highest total meat intake had a 53% (model 4: HR 1.53, 95% CI 1.05-2.21) increased 10-year CHD risk compared to those with the lowest intake. Those with the highest red meat intake had a 55% (model 3: HR 1.55, 95% CI 1.16-2.06) increased 10-year CHD risk compared to those with the lowest intake. No association was observed between poultry or processed meat intake and 10-year CHD risk.

CONCLUSIONS

Consumption of total meat and red meat was associated with a higher risk of CHD in Korean male adults. Further studies are needed to provide criteria for the appropriate meat intake by meat type to reduce CHD risk.

Red and processed meat intakes and cardiovascular disease and type 2 diabetes mellitus: An umbrella systematic review and assessment of causal relations using Bradford Hill's criteria

Observational research suggests higher red and processed meat intakes predict greater risks of developing or dying from cardiovascular diseases (CVD) and type 2 diabetes mellitus (T2DM), but this research limits causal inference. This systematic review of reviews utilizes both observational and experimental research findings to infer causality of these relations. Reviews from four databases were screened by two researchers. Reviews included unprocessed red meat (URM), processed meat (PM), or mixed URM + PM intake, and reported CVD or T2DM outcomes. Twenty-nine reviews were included, and causality was inferred using Bradford Hill's Criteria. Observational assessments of CVD outcomes and all meat types consistently reported weak associations while, T2DM outcomes and PM and Mixed URM + PM assessments consistently reported strong associations. Experimental assessments of Mixed URM + PM on CVD and T2DM risk factors were predominately not significant which lacked coherence with observational findings. For all meat types and outcomes, temporality and plausible mechanisms were established, but specificity and analogous relationships do not support causality. Evidence was insufficient for URM and T2DM. More experimental research is needed to strengthen these inferences. These results suggest that red and processed meat intakes are not likely causally related to CVD but there is potential for a causal relationship with T2DM.

Total, red and processed meat consumption and human health: an umbrella review of observational studies

Meat consumption has represented an important evolutionary step for humans. However, modern patterns of consumption, including excess intake, type of meat and cooking method have been the focus of attention as a potential cause of rise in non-communicable diseases. The aim of this study was to investigate the association between total, red and processed meat with health outcomes and to assess the level of evidence by performing a systematic search of meta-analyses of prospective cohort studies. Convincing evidence of the association between increased risk of (i) colorectal adenoma, lung cancer, CHD and stroke, (ii) colorectal adenoma, ovarian, prostate, renal and stomach cancers, CHD and stroke and (iii) colon and bladder cancer was found for excess intake of total, red and processed meat, respectively. Possible negative associations with other health outcomes have been reported. Excess meat consumption may be detrimental to health, with a major impact on cardiometabolic and cancer risk.

An Update on the Epidemiology of Type 2 Diabetes: A Global Perspective

Type 2 diabetes (T2D) is a public health burden associated with immense health care and societal costs, early death, and morbidity. Largely because of epidemiologic changes, including nutrition transitions, urbanization, and sedentary lifestyles, T2D is increasing in every region of the world, particularly in low-income and middle-income countries. This article highlights global trends in T2D and discusses the role of genes, early-life exposures, and lifestyle risk factors in the cause of T2D, with an emphasis on populations in current hotspots of the epidemic. It also considers potential impacts of the coronavirus disease 2019 pandemic and T2D prevention policies and action.

Associations between red meat, processed red meat and total red and processed red meat consumption, nutritional adequacy and markers of health and cardio-metabolic diseases in British adults: a cross-sectional analysis using data from UK National Diet and Nutrition Survey

PURPOSE

To determine the association between red meat (RM), processed red meat (PRM) and total red and processed red meat (TRPRM) consumption on nutritional adequacy and markers of health and cardio-metabolic diseases in British adults.

METHODS

In this cross-sectional study of adults (19-64 y) from the National Diet and Nutrition Survey (NDNS) (n = 1758), RM and PRM consumption were assessed from 4 day estimated food diaries. Anthropometric measures, blood pressure (BP), pulse pressure (PP), plasma glucose, HbA1c, C-reactive protein, TAG, TC, LDL-C and HDL-C from the NDNS were used.

RESULTS

43% of adults (men 57% and women 31%) consumed more than the 70 g/d TRPRM guidelines. Fewer adults in the highest tertile of TRPRM intake were below lower reference nutrient intakes (LRNIs), particularly for zinc and iron, respectively. In model 3 (controlled for age, energy intake, socioeconomic classification, number of daily cigarettes, BMI, dietary factors), higher RM consumption was associated with being significantly taller (model 3: P-ANCOVA = 0.006; P-T3/T1 = 0.0004) in men and lower diastolic BP (model 3: P-ANCOVA = 0.004; P-T3/T2 = 0.002) in women. Higher PRM in men was associated with significantly higher plasma ferritin concentration (model 3: P-ANCOVA = 0.0001; P-T2/T1 = 0.0001), being taller (P-ANCOVA = 0.019; P-T1/T2 = 0.047, T1/T3 = 0.044), increased body weight (model 3: P-ANCOVA = 0.001; P-T1/T3 = 0.0001), BMI (model 3: P-ANCOVA = 0.007; P-T1/T3 = 0.006) and smaller hip circumference (model 3: P-ANCOVA = 0.006; P-T3/T1 = 0.024; P-T2/T1 = 0.013) and in women significantly higher TC (model 3: P-ANCOVA = 0.020; P-T3/T2 = 0.016), LDL-C (P-ANCOVA = 0.030; P-T3/T2 = 0.025), HbA1c (model 3: P-ANCOVA = 0.0001; P-T2/T1 = 0.001; P-T3/T2 = 0.001) and higher PP (model 3: P-ANCOVA = 0.022; P-T3/T1 = 0.021). Higher PRM consumption was associated with significantly higher BMI and hip circumference in men, and higher TC, LDL-C, HbA1c and PP in women, which was not observed for RM consumption.

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.

Animal performance, ingestive behavior, and carcass characteristics of grazing-finished steers supplemented with castor bean (Ricinus communis L.) meal protein

This study was carried out to evaluate the effects of replacing soybean meal by castor bean meal on nutrient intake, digestibility, animal performance, ingestive behavior activities, carcass characteristics, and fatty acid profile from steers finished in pasture. Crossbred steers were weighed to determine the initial body weight (331.6 ± 37.4 kg), which were kept in 4 paddocks (8 animals/paddock), on pastures of Brachiaria decumbens during the finishing phase. Dietary treatments included CC00-without castor bean meal; CC33-153 g/kg of castor bean meal; CC66-308 g/kg of castor bean meal; and CC100-434 g/kg of castor bean meal. No treatment effects were detected (P > 0.05) for final body weight, average daily gain, feed efficiency, and hot carcass weight. The DM, CP, NDF, and NFC total intake were lowest (P < 0.01) for steers fed CC100 diet than others. No treatment effects were detected (P > 0.05) for digestibility. For ingestive behavior activities, data on DM and NDF from feeding rate were greater (P < 0.01) in CC00 v. castor bean meal steers. DM and NDF from rumination rate were greater (P < 0.01) in CC33 v. CC100 steers that was the lowest. Carcass measures, carcass composition, chemical composition of Longissimus thoracis muscle, and profile and the sum of fatty acids were not affected (P > 0.05) by castor bean meal replacement on the diets. Results from this experiment suggest that castor bean meal may replace soybean meal in pasture supplementation without altered digestibility, carcass characteristics, and fatty acid profile.

Effects of meat and processed meat consumption on the lipid profile in the population with cardiovascular diseases

Meat represents an important source of high-quality dietary protein for a large proportion of the global population. Also, red meat, in particular, significantly contributes to the intake of a wide range of micronutrients, including iron, zinc, selenium, vitamin D, and vitamin B12. Excessive consumption of meat and meat products is often associated with overconsumption of energy and fat, resulting in excess weight, obesity, and an increased risk of chronic diseases, such as cardiovascular disease and type 2 diabetes. This study aims to evaluate the relationship between meat and processed meat consumption frequencies and lipid profile in a group of 800 randomly selected patients hospitalized in the Cardiocentre Nitra. Patients were 20 – 101 years, (men, the average age was 61.13 ±10.47 years). The data necessary for the detection of dietary habits were obtained by a questionnaire method. Statistical comparisons between groups were made utilizing a one-way analysis of variance (one-way ANOVA) followed by Tukey's post hoc test. Our results show, that most respondents consume meat 1 – 2 times per week, while we did not notice a significant effect (p >0.05) of the type of meat on the lipid profile. The highest T-C, LDL-C, and TG values were seen in men who consume pork 3 – 4 times per week. Statistically significant was only the effect of pork meat on total cholesterol and triglycerides (p <0.05). In the consumption of beef and poultry, there was a non-significant effect on biochemical parameters of blood (p >0.05). We recorded a significant effect (p ˂0.05) of the consumption of frankfurters between consumption 1 – 2 times per week and 3 – 4 times per week. Up to 40.2% of respondents consume salami 3 – 4 times per week, and we recorded a significant effect on LDL levels between consumption 1 – 2 times per week and sometimes (p ˂0.05). Respondents who consume sausage, headcheese, and others products 1 – 2 times a week have non-significant higher T-C, LDL, TG, and lower HDL compared to less frequent consumption. High consumption of meat, mainly pork and processed meat seems to be associated with higher levels of total cholesterol, LDL cholesterol, and triglycerides.

Effect of Lower Versus Higher Red Meat Intake on Cardiometabolic and Cancer Outcomes: A Systematic Review of Randomized Trials

This article has been corrected. The original version (PDF) is appended to this article as a Supplement.

BACKGROUND

Few randomized trials have evaluated the effect of reducing red meat intake on clinically important outcomes.

PURPOSE

To summarize the effect of lower versus higher red meat intake on the incidence of cardiometabolic and cancer outcomes in adults.

DATA SOURCES

EMBASE, CENTRAL, CINAHL, Web of Science, and ProQuest from inception to July 2018 and MEDLINE from inception to April 2019, without language restrictions.

STUDY SELECTION

Randomized trials (published in any language) comparing diets lower in red meat with diets higher in red meat that differed by a gradient of at least 1 serving per week for 6 months or more.

DATA EXTRACTION

Teams of 2 reviewers independently extracted data and assessed the risk of bias and the certainty of the evidence.

DATA SYNTHESIS

Of 12 eligible trials, a single trial enrolling 48 835 women provided the most credible, though still low-certainty, evidence that diets lower in red meat may have little or no effect on all-cause mortality (hazard ratio [HR], 0.99 [95% CI, 0.95 to 1.03]), cardiovascular mortality (HR, 0.98 [CI, 0.91 to 1.06]), and cardiovascular disease (HR, 0.99 [CI, 0.94 to 1.05]). That trial also provided low- to very-low-certainty evidence that diets lower in red meat may have little or no effect on total cancer mortality (HR, 0.95 [CI, 0.89 to 1.01]) and the incidence of cancer, including colorectal cancer (HR, 1.04 [CI, 0.90 to 1.20]) and breast cancer (HR, 0.97 [0.90 to 1.04]).

LIMITATIONS

There were few trials, most addressing only surrogate outcomes, with heterogeneous comparators and small gradients in red meat consumption between lower versus higher intake groups.

CONCLUSION

Low- to very-low-certainty evidence suggests that diets restricted in red meat may have little or no effect on major cardiometabolic outcomes and cancer mortality and incidence.

PRIMARY FUNDING SOURCE

None (PROSPERO: CRD42017074074).

Animal and Plant Protein Sources and Cardiometabolic Health

The sources or types of protein in the diet have long been overlooked regarding their link to cardiometabolic health. The picture is complicated by the fact that animal and plant proteins are consumed along with other nutrients and substances which make up the "protein package" so plant and animal protein come with clear nutrient clusters. This review aimed at deciphering the relation between plant and animal protein and cardiometabolic health by examining different nutritional levels (such as amino acids, protein type, protein foods, protein patterns, and associated overall dietary and nutrient patterns) and varying levels of scientific evidence [basic science, randomized controlled trials (RCTs), observational data]. Plant protein in Western countries is a robust marker of nutrient adequacy of the diet, whereas the contribution of animal protein is highly heterogeneous. Yet recent data from large cohorts have confirmed that total and animal proteins are associated with the risk of cardiovascular disease and diabetes, even when fully adjusting for lifestyle and dietary or nutritional factors. Here again, there is marked variability depending on the type of animal protein. Protein from processed red meat and total red meat on the one hand, and from legumes, nuts, and seeds on the other, are often reported at the extremes of the risk range. RCTs using purified proteins have contributed little to the topic to date, inasmuch as the findings cannot readily be extrapolated to current or near-future diets, but RCTs studying whole protein foods have shown a beneficial effect of pulses. Despite the fact that many of the benefits of plant protein reported in observational or interventional studies may stem from the protein package that they convey and the nutrients that they displace, there are also important indications that protein per se may affect cardiometabolic health via the many amino acids that are present in typically contrasting levels in plant compared with animal proteins.

Effects of red meat, white meat, and nonmeat protein sources on atherogenic lipoprotein measures in the context of low compared with high saturated fat intake: a randomized controlled trial

BACKGROUND

Dietary recommendations to limit red meat are based on observational studies linking intake to cardiovascular disease (CVD) risk together with the potential of its saturated fatty acid (SFA) content to raise low-density lipoprotein (LDL) cholesterol. However, the relation of white meat to CVD risk, and the effects of dietary protein source on lipoprotein particle subfractions, have not been extensively evaluated.

OBJECTIVE

We tested whether levels of atherogenic lipids and lipoproteins differed significantly following consumption of diets with high red meat content compared with diets with similar amounts of protein derived from white meat or nonmeat sources, and whether these effects were modified by concomitant intake of high compared with low SFAs.

METHODS

Generally healthy men and women, 21-65 y, body mass index 20-35 kg/m2, were randomly assigned to 1 of 2 parallel arms (high or low SFA) and within each, allocated to red meat, white meat, and nonmeat protein diets consumed for 4 wk each in random order. The primary outcomes were LDL cholesterol, apolipoprotein B (apoB), small + medium LDL particles, and total/high-density lipoprotein cholesterol.

RESULTS

Analysis included participants who completed all 3 dietary protein assignments (61 for high SFA; 52 for low SFA). LDL cholesterol and apoB were higher with red and white meat than with nonmeat, independent of SFA content (P < 0.0001 for all, except apoB: red meat compared with nonmeat [P = 0.0004]). This was due primarily to increases in large LDL particles, whereas small + medium LDL and total/high-density lipoprotein cholesterol were unaffected by protein source (P = 0.10 and P = 0.51, respectively). Primary outcomes did not differ significantly between red and white meat. Independent of protein source, high compared with low SFA increased LDL cholesterol (P = 0.0003), apoB (P = 0.0002), and large LDL (P = 0.0002).

CONCLUSIONS

The findings are in keeping with recommendations promoting diets with a high proportion of plant-based food but, based on lipid and lipoprotein effects, do not provide evidence for choosing white over red meat for reducing CVD risk. This trial was registered at Clinicaltrials.gov as NCT01427855.

Association between Dietary Cholesterol and Their Food Sources and Risk for Hypercholesterolemia: The 2012⁻2016 Korea National Health and Nutrition Examination Survey

It remains unclear whether cholesterol intake can increase serum cholesterol. Therefore, the present study aimed to investigate the hypothesis that the risk for hypercholesterolemia was not associated with intake of dietary cholesterol after adjusting for saturated fatty acid (SFA). Based on the data from the 2012–2016 KNHANES, dietary cholesterol was positively associated with the risk for abnormalities in total cholesterol (TC) (odds ratio (OR): 1.153, 95% confidence interval (CI): 0.995–1.337; p = 0.028) and low-density lipoprotein cholesterol (LDL-C) (OR: 1.186, 95% CI: 1.019–1.382; p = 0.018) levels before adjusting for SFA; after adjusting for SFA, no significant associations were found between these variables. The mediation analysis showed that dietary cholesterol had no direct effects on the serum levels of TC and LDL-C; in contrast, SFA had significant indirect effects on the association between dietary cholesterol and serum levels of TC and LDL-C. Furthermore, processed meats, but not eggs and other meats, were positively associated with the risk for abnormalities in both TC (OR: 1.220, 95% CI: 1.083–1.374; p = 0.001) and LDL-C (OR: 1.193, 95% CI: 1.052–1.354; p = 0.004) levels. The present study suggested that higher intake of processed meats with high SFA, but not dietary cholesterol was associated with higher risk for abnormalities in TC and LDL-C levels.

Fat from dairy foods and 'meat' consumed within recommended levels is associated with favourable serum cholesterol levels in institutionalised older adults

CVD is common in older adults. Consumption of ‘meat’ (beef, pork, lamb, game, poultry, seafood, eggs) and dairy foods (milk, cheese, yoghurt) is encouraged in older adults as these foods provide protein and nutrients such as essential fatty acids, Ca, Fe, Zn and vitamins A, D and B₁₂ required for healthy ageing. However, these foods also contain saturated fats considered detrimental to cardiovascular health. To determine the effect of their consumption on CVD risk we assessed associations between fat intake from ‘meat’ and dairy foods and serum cholesterol levels in 226 aged-care residents (mean age 85·5 years, 70 % female). Dietary intake was determined over 2 d using visual estimation of plate waste. Fat content of foods was determined using nutrition analysis software (Xyris, Australia). Fasting serum total cholesterol (TC), LDL-cholesterol and HDL-cholesterol were measured, and the TC:HDL-cholesterol ratio calculated. Associations were determined using random-effect models adjusted for CVD risk factors using STATA/IC 13.0. Total fat and saturated fat from ‘meat’ and dairy foods were associated with higher serum HDL-cholesterol levels, and dairy fat intake and number of servings were associated with a lower TC:HDL-cholesterol ratio. Every 10 g higher intake of fat and saturated fat from dairy products, and each additional serving was associated with a −0·375 (95 % CI −0·574, −0·175; P = 0·0002), a −0·525 (95 % CI −0·834, −0·213; P = 0·001) and a −0·245 (95 % CI −0·458, −0·033; P = 0·024) lower TC:HDL-cholesterol ratio, respectively. Provision of dairy foods and ‘meat’ in recommended amounts to institutionalised older adults potentially improves intakes of key nutrients with limited detriment to cardiovascular health.

Adopting a Mediterranean-Style Eating Pattern with Different Amounts of Lean Unprocessed Red Meat Does Not Influence Short-Term Subjective Personal Well-Being in Adults with Overweight or Obesity

Background

Reducing red meat intake is commonly recommended. Limited observational studies suggest that healthy eating patterns with red meat are associated with improved quality of life.

Objective

The secondary objectives of this randomized crossover controlled-feeding trial were to assess the effects of following a Mediterranean-style eating pattern (Med-Pattern) with different amounts of red meat on indexes of personal well-being (i.e., perceived quality of life, mood, and sleep) in overweight or obese adults. We hypothesized that following a Med-Pattern would improve these outcomes, independent of red meat intake amount.

Methods

Forty-one participants [aged 46 ± 2 y; body mass index (kg/m2): 30.5 ± 0.6; n = 28 women, n = 13 men) were provided Med-Pattern foods for two 5-wk periods separated by 4 wk of self-selected eating. The Med-Red Pattern contained ∼500 g/wk (typical US intake), and the Med-Control Pattern contained ∼200 g/wk (commonly recommended intake in heart-healthy eating patterns) of lean, unprocessed beef or pork compensated with mainly poultry and dairy. Baseline and postintervention outcomes measured were perceived quality of life via the MOS 36-Item Short-Form Health Survey, version 2 (SF-36v2), daily mood states via the Profile of Mood States (POMS), sleep perceptions via the Pittsburgh Sleep Quality Index, and sleep patterns via actigraphy. Data were analyzed via a doubly repeated-measures ANOVA adjusted for age, sex, and body mass at each time point.

Results

Following a Med-Pattern did not change domains of physical health, mental health, total mood disturbances, sleep perceptions, and sleep patterns but improved subdomains of physical health role limitations (SF-36v2: 93.6-96.7%; P = 0.038), vitality (SF-36v2: 57.9-63.0%; P = 0.020), and fatigue (POMS: 2.9-2.5 arbitrary units; P = 0.039). There were no differences between the Med-Red and Med-Control Patterns (time × pattern, P-interaction > 0.05).

Conclusion

Following a Med-Pattern, independent of lean, unprocessed red meat intake, may not be an effective short-term strategy to meaningfully improve indexes of personal well-being in adults who are overweight or obese. This trial was registered at clinicaltrials.gov as NCT02573129.

Fish consumption, mercury exposure, and the risk of cholesterol profiles: findings from the Korea National Health and Nutrition Examination Survey 2010-2011

In this study, the associations between mercury (Hg) exposure and cholesterol profiles were analyzed, and increased Hg levels and cholesterol profiles according to the amount of fish consumption were evaluated. Data on levels of blood Hg, the frequency of fish consumption, total blood cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) in 3951 adults were obtained from the Korea National Health and Nutrition Examination Survey 2010-2011 database. To compare the distribution for each log-transformed indicator, Student's t-test and analysis of variance were carried out, and the groups were classified according to the frequency of fish consumption through linear regression analysis; the association between Hg level and cholesterol profiles in each group was analyzed. The blood Hg levels (arithmetic mean, median, and geometric mean) for all target participants were 4.59, 3.66, and 3.74 µg/L, respectively. The high cholesterol group, low HDL-C group, and high TG group showed a statistically and significantly higher blood Hg level than the low-risk group. In both sexes, as the frequency of fish consumption increased, blood Hg level also increased, but TC, HDL-C, LDL-C, and TG did not show a similar trend. Increased blood Hg level showed a significant association with increased TC and LDL-C. This statistical significance was maintained in the group with less frequent fish consumption (<4 times per month), but the group with frequent fish consumption (>8 times per month) did not show a similar trend. The results of this study suggest that fish consumption increases the level of Hg exposure, and that as the level of Hg exposure increases, the levels of cholesterol profiles increase. However, this study also suggests that the levels of cholesterol profiles in those with frequent fish consumption can be diminished.

A Contemporary Review of the Relationship between Red Meat Consumption and Cardiovascular Risk

Cardiovascular diseases burden is increasing due to aging populations and represents one of the major health issues worldwide. Dietary habits have been extensively studied in the cardiovascular field despite the difficulty in the quantification of the assumption of each single food and the observation that several foods affect cardiovascular risk with opposite effects. Moreover, some older findings have been reverted by more recent studies. Red meat has been widely studied in this context, and it has been suggested to increase cardiovascular risk primarily by causing dyslipidemia. Our aim is to review the relationship between red meat assumption and cardiovascular risk and to present novel findings regarding their link.

Associations between dietary patterns and serum lipids, apo and C-reactive protein in an adult population: evidence from a multi-city cohort in South America

Several previous epidemiological studies from developed countries have shown that an unhealthy dietary pattern affects plasma lipid levels and inflammation biomarkers. We assessed the cross-sectional associations between dietary patterns and cardiovascular risk factors among 961 adults from a multi-city cohort in South America. We conducted a principal component analysis to derive dietary patterns. As outcomes, we examined plasma levels of apo A-I, apo B, high-sensitivity C-reactive protein (hs-CRP), LDL-, HDL- and serum total cholesterol and TAG. The crude and adjusted changes in each outcome were estimated for quartiles of dietary patterns using multivariable linear regression models. The prudent pattern (PP) characterised by higher intake of fruits, vegetables, fish, seafood, whole cereal and low-fat dairy products was associated with reduced plasma concentrations of apo B (-8·5 mg/l), total cholesterol (-18·8 mg/dl) and LDL-cholesterol (-16·5 mg/dl) and hs-CRP (-1·6 mg/l) in men. In women also reduced plasma concentrations of apo B (-6·6 mg/l), total (-12·0 mg/dl) and LDL (-9·3 mg/dl). The 'Western-like' pattern characterised by higher intake of eggs, pastry and cakes, pizza, snacks, refined grains, red meat, vegetable oils and poultry was not significantly associated with any of the selected serum lipid or inflammatory biomarkers. The explained variances were 10·3 and 7·4 %, respectively. The PP was associated with better lipid profile, mainly lower atherogenic particles (apo B) and LDL-cholesterol and serum total cholesterol. This study provides possible evidence of a prudent diet in South American populations to help reduce the burden of CVD.

Total red meat intake of ≥0.5 servings/d does not negatively influence cardiovascular disease risk factors: a systemically searched meta-analysis of randomized controlled trials

BACKGROUND

Observational associations between red meat intake and cardiovascular disease (CVD) are inconsistent. There are limited comprehensive analyses of randomized controlled trials (RCTs) that investigate the effects of red meat consumption on CVD risk factors.

OBJECTIVE

The purpose of this systematically searched meta-analysis was to assess the effects of consuming ≥0.5 or <0.5 servings of total red meat/d on CVD risk factors [blood total cholesterol (TC), LDL cholesterol, HDL cholesterol, triglycerides, ratio of TC to HDL cholesterol (TC:HDL), and systolic and diastolic blood pressures (SBP and DBP, respectively)]. We hypothesized that the consumption of ≥0.5 servings of total red meat/d would have a negative effect on these CVD risk factors.

DESIGN

Two researchers independently screened 945 studies from PubMed, Cochrane Library, and Scopus databases and extracted data from 24 qualified RCTs. Inclusion criteria were 1) RCT, 2) subjects aged ≥19 y, 3) consumption of ≥0.5 or <0.5 total red meat servings/d [35 g (1.25 ounces)], and 4) reporting ≥1 CVD risk factor. We performed an adjusted 2-factor nested ANOVA mixed-effects model procedure on the postintervention values of TC, LDL cholesterol, HDL cholesterol, TC:HDL cholesterol, triglycerides, SBP, and DBP; calculated overall effect sizes of change values; and used a repeated-measures ANOVA to assess pre- to postintervention changes.

RESULTS

Red meat intake did not affect lipid-lipoprotein profiles or blood pressure values postintervention (P > 0.05) or changes over time [weighted mean difference (95% CI): -0.01 mmol/L (-0.08, 0.06 mmol/L), 0.02 mmol/L (-0.05, 0.08 mmol/L), 0.03 mmol/L (-0.01, 0.07 mmol/L), and 0.04 mmol/L (-0.02, 0.10 mmol/L); -0.08 mm Hg (-0.26, 0.11 mm Hg); and -1.0 mm Hg (-2.4, 0.78 mm Hg) and 0.1 mm Hg (-1.2, 1.5 mm Hg) for TC, LDL cholesterol, HDL cholesterol, triglycerides, TC:HDL cholesterol, SBP, and DBP, respectively]. Among all subjects, TC, LDL cholesterol, HDL cholesterol, TC:HDL cholesterol, triglycerides, and DBP, but not SBP, decreased over time (P < 0.05).

CONCLUSIONS

The results from this systematically searched meta-analysis of RCTs support the idea that the consumption of ≥0.5 servings of total red meat/d does not influence blood lipids and lipoproteins or blood pressures.

Research gaps in evaluating the relationship of meat and health

Humans evolved as omnivores and it has been proposed that cooking meat allowed for evolution of larger brains that has led to our success as a species. Meat is one of the most nutrient dense foods, providing high-quality protein, heme iron, zinc, and vitamins B6 and B12. Despite these advantages, epidemiologic studies have linked consumption of red or processed meat with obesity, type 2 diabetes, cardiovascular diseases, and cancers of multiple organs. Most observational studies report small, increased relative risks. However, there are many limitations of such studies including inability to accurately estimate intake, lack of prespecified hypotheses, multiple comparisons, and confounding from many factors - including body weight, fruit/vegetable intake, physical activity, smoking, and alcohol - that correlate significantly either positively or negatively with meat intake and limit the reliability of conclusions from these studies. The observational studies are heterogeneous and do not fulfill many of the points proposed by AB Hill in 1965 for inferring causality; his most important factor was strength of the association which in dietary studies is usually <1.5 but is not considered adequate in virtually all other areas of epidemiology outside nutrition. Accepting small, statistically significant risks as "real" from observational associations, the field of nutrition has a long list of failures including beta-carotene and lung cancer, low-fat diets and breast cancer or heart disease that have not been confirmed in randomized trials. Moderate intake of a variety of foods that are enjoyed by people remains the best dietary advice.

Red meat consumption and ischemic heart disease. A systematic literature review

Several lines of evidence attest that diet may strongly influence the cardiovascular risk. We performed an electronic search in Medline (with PubMed interface), Scopus and ISI Web of Science, to identify epidemiological studies on the association between red meat intake and the overall risk of ischemic heart disease (IHD). Eleven studies (8 prospective and 3 case-control) were finally selected for this systematic literature review. Although a larger intake of red meat was found to be a significant risk factor for IHD in four studies (2 prospective and 2 case-control), no significant association was found in five other trials (4 prospective and 1 case-control). We suggest that future diet recommendations for prevention of cardiovascular disease should take into account that the current literature data does not support the existence of a clear relationship between large intake of red meat and increased risk of myocardial ischemia.

Saturated Fats Versus Polyunsaturated Fats Versus Carbohydrates for Cardiovascular Disease Prevention and Treatment

The effects of saturated fatty acids (SFAs) on cardiovascular disease (CVD) risk are modulated by the nutrients that replace them and their food matrices. Replacement of SFAs with polyunsaturated fatty acids has been associated with reduced CVD risk, although there is heterogeneity in both fatty acid categories. In contrast, replacement of SFAs with carbohydrates, particularly sugar, has been associated with no improvement or even a worsening of CVD risk, at least in part through effects on atherogenic dyslipidemia, a cluster of traits including small, dense low-density lipoprotein particles. The effects of dietary SFAs on insulin sensitivity, inflammation, vascular function, and thrombosis are less clear. There is growing evidence that SFAs in the context of dairy foods, particularly fermented dairy products, have neutral or inverse associations with CVD. Overall dietary patterns emphasizing vegetables, fish, nuts, and whole versus processed grains form the basis of heart-healthy eating and should supersede a focus on macronutrient composition.

Inclusion of red meat in healthful dietary patterns

Dietary patterns are an important concept in dietary recommendations. The Western pattern is most commonly defined as a diet characterized by high intakes of refined grains, sugar and red meat, and has been shown to be associated with increased risks for certain types of cancer, coronary heart disease, diabetes, and obesity. However, isolating the independent effects of individual foods on health outcomes is central to helping individuals choose foods to build healthier dietary patterns to which they can adhere. Red meat is a popular source of high quality protein and provides a variety of essential nutrients that improve overall diet quality. It is also a source of saturated fatty acids, which observational evidence suggests are associated with heart disease, although recent data challenge this. Several studies have shown that lean red meat can be successfully included in recommended heart-healthy dietary patterns without detriment to blood lipids. Furthermore, increased dietary protein has been shown to promote healthy body weight and composition, in part by increasing satiety, and to improve vitality and stamina.