Effects of Total Red Meat Intake on Glycemic Control and Inflammatory Biomarkers: A Meta-Analysis of Randomized Controlled Trials

Abstract

Our objective was to conduct a systematic review and meta-analysis to assess the effects of total red meat (TRM) intake on glycemic control and inflammatory biomarkers using randomized controlled trials of individuals free from cardiometabolic disease. We hypothesized that higher TRM intake would negatively influence glycemic control and inflammation based on positive correlations between TRM and diabetes. We found 24 eligible articles (median duration, 8 weeks) from 1172 articles searched in PubMed, Cochrane, and CINAHL up to August 2019 that included 1) diet periods differing in TRM; 2) participants aged ≥19 years; 3) included either men or women who were not pregnant/lactating; 4) no diagnosed cardiometabolic disease; and 5) data on fasting glucose, insulin, HOMA-IR, glycated hemoglobin (HbA1c), C-reactive protein (CRP), or cytokines. We used 1) a repeated-measures ANOVA to assess pre to post diet period changes; 2) random-effects meta-analyses to compare pre to post changes between diet periods with ≥ vs. <0.5 servings (35g)/day of TRM; and 3) meta-regressions for dose-response relationships. We grouped diet periods to explore heterogeneity sources, including risk of bias, using the National Heart, Lung, and Blood Institute's Quality Assessment of Controlled Interventions Studies. Glucose, insulin, and HOMA-IR values decreased, while HbA1c and CRP values did not change during TRM or alternative diet periods. There was no difference in change values between diet periods with ≥ vs. <0.5 servings/day of TRM [weighted mean differences (95% CIs): glucose, 0.040 mmol/L (−0.049, 0.129); insulin, −0.710 pmol/L (−6.582, 5.162); HOMA-IR, 0.110 (−0.072, 0.293); CRP, 2.424 nmol/L (−1.460, 6.309)] and no dose response relationships (P > 0.2). Risk of bias (85% of studies were fair to good) did not influence results. Total red meat consumption, for up to 16 weeks, does not affect changes in biomarkers of glycemic control or inflammation for adults free of, but at risk for, cardiometabolic disease. This trial was registered at PROSPERO as 2018 CRD42018096031.

The Role of Changes in Cumulative Lipid Parameter Burden in the Pathogenesis of Type 2 Diabetes Mellitus: A Cohort Study of People Aged 35–65 Years in Rural China

“… 38–40 Conversely, the results of other random intervention trials have shown inconsistent evidence. 41 However, recent studies have found that replacing red meat with other nonmeat protein foods can reduce the risk of T2DM, 42 , 43 which subsequently demonstrates the role of red meat in T2DM. In the present study, we found that the median refined grain intake was the same between the two groups, but the average refined grain intake of T2DM patients was 346.27 g, which was higher than that of participants without diabetes (318.66 g).…”

Animal-based food choice and associations with long-term weight maintenance and metabolic health after a large and rapid weight loss: The PREVIEW study

“…In addition, most prospective cohort studies [8e11,43] used hard disease endpoints (i.e. risk of disease) over 5 years or longer, whereas the present study and RCTs [33,34] used intermediate disease markers (e.g. fasting insulin, HOMA-IR, triacylglycerols, and HDLcholesterol) over a shorter period.…”

“…In the present study, our findings do not support that adults after rapid weight loss should reduce or avoid unprocessed red meat intake. Similarly, in two meta-analyses of randomised controlled trials (RCTs), O'Connor et al [33,34] found that intake of red meat did not result in deterioration of glycaemic and cardiometabolic risk factors, although the RCTs included did not have a large weight loss phase. In addition, although low red meat intake is recommended by DASH dietary patterns, some RCTs showed that DASH diets had equivalent efficacy in decreasing cardiometabolic risk factors when they contained higher amounts of red meat [35,36].…”

Anti-Inflammatory Nutrients and Obesity-Associated Metabolic-Inflammation: State of the Art and Future Direction

“…Food groups rich in vegetable fats, such as olive oil [ 26 ] and nuts [ 26 ], as well as other plant-foods such as soy [ 27 ], legumes, and pulses [ 28 ], have been shown to cause a non-significant decrease in CRP levels. Among animal foods, dairy products [ 29 ] have shown a significant reduction effect on CRP levels, while others, such as red meat [ 30 ] and eggs [ 31 ], have been shown to produce null results.…”