Yu Wang

Background: Previous research demonstrates that adopting, abandoning, and re-adopting (i.e., cycling) a healthy dietary pattern (HDP) improved, reverted, and re-improved cardiovascular disease (CVD) risk factors. In addition, changes in CVD risk factors are associated with dietary modifications of gut microbiota. Objective: We sought to assess the effects of cycling an HDP on gut microbiota and CVD risk factors. Methods: Retrospectively, we used data from a randomized controlled, crossover trial with three 3-week controlled dietary interventions, each separated by a 5-week period of participant-chosen, uncontrolled food intake. Seventeen participants (10 males, 7 females, age 26 ± 4 years old, BMI 23 ± 3 kg/m²) all consumed intervention diets that followed healthy U.S.-style dietary patterns. Gut microbiota composition and cardiovascular risk factors were measured before and after each HDP. Results: Repeatedly adopting and abandoning an HDP led to a cycling pattern of changes in the gut microbial community and taxonomic composition. During the HDP cycles, relative abundances of several bacterial taxa (e.g., Collinsella, Mediterraneibacter, Romboutsia, and Dorea) decreased and returned to baseline repeatedly. Similar HDP cycling occurred for multiple CVD risk factors (i.e., serum total cholesterol and LDL-C concentrations). Consistent negative associations were observed between changes in Mediterraneibacter or Collinsella and serum total cholesterol/HDL-C ratio. Conclusions: These results support previous findings that HDP cycling affected multiple CVD risk factors and expand the HDP cycling phenomenon to include several bacterial taxa. Young adults are encouraged to adopt and sustain a healthy dietary pattern to improve cardiovascular health, potentially through modifying gut microbiota composition.

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.

Mushrooms, unique edible fungi, contain several essential nutrients and bioactive compounds which may positively influence cardiometabolic health. Despite a long history of consumption, the health benefits of mushrooms are not well documented. We conducted a systematic review to assess the effects of and associations between mushroom consumption and cardiometabolic disease (CMD)-related risk factors and morbidities/mortality. We identified 22 articles (11 experimental and 11 observational) from five databases meeting our inclusion criteria. Limited evidence from experimental research suggests mushroom consumption improves serum/plasma triglycerides and hs-CRP, but not other lipids, lipoproteins, measures of glucose control (fasting glucose and HbA1c), or blood pressure. Limited evidence from observational research (seven of 11 articles with a posteriori assessments) suggests no association between mushroom consumption and fasting blood total or LDL cholesterol, glucose, or morbidity/mortality from cardiovascular disease, coronary heart disease, or type 2 diabetes mellitus. Other CMD health outcomes were deemed either inconsistent (blood pressure, HDL cholesterol, and triglycerides) or insufficient (HbA1c/hyperglycemia, hs-CRP, cerebrovascular disease, and stroke). The majority of the articles vetted were rated “poor” using the NHLBI study quality assessment tool due to study methodology and/or poor reporting issues. While new, high-quality experimental and observational research is warranted, limited experimental findings suggest greater mushroom consumption lowers blood triglycerides and hs-CRP, indices of cardiometabolic health.

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.

Purpose of Review To summarize recent evidence from randomized controlled feeding trials (RCTs) on the effects of consuming plant- and animal-based protein-rich foods on cardiovascular health of adults. Recent Findings Results from meta-analyses of RCTs exemplify the importance of considering relative effects of protein-rich foods, i.e., when intake of one food increases, intake of another food likely decreases. Results from short-term RCTs showed that overall diet quality is more influential for improving cardiovascular disease (CVD) risk factors than intake of a single protein-rich food, e.g., red meat. Yet, assessing long-term CVD risk associated with intake of a single protein-rich food as part of a dietary pattern is methodologically challenging. While accumulating evidence suggests gut microbiota as a potential mediator for such effects, current knowledge is preliminary and restricts causal or functional inferences. Summary A variety of protein-rich foods, both plant- and animal-based, should be consumed as part of nutrient-dense dietary patterns to meet nutrient needs and improve cardiovascular health for adults.

A Mediterranean-style eating pattern (MED-EP) may include moderate red meat intake. However, it is unknown if the pro-atherogenic metabolite trimethylamine N-oxide (TMAO) is affected by the amount of red meat consumed with a MED-EP. The results presented are from a secondary, retrospective objective of an investigator-blinded, randomised, crossover, controlled feeding trial (two 5-week interventions separated by a 4-week washout) to determine if a MED-EP with 200 g unprocessed lean red meat/week (MED-CONTROL) reduces circulating TMAO concentrations compared to a MED-EP with 500 g unprocessed lean red meat/week (MED-RED). Participants were seventy-seven women and twelve men (n39 total) who were either overweight or obese (BMI: mean (30·5) (sem0·3) kg/m²). Serum samples were obtained following an overnight fast both before (pre) and after (post) each intervention. Fasting serum TMAO, choline, carnitine and betaine concentrations were measured using a targeted liquid chromatography-MS. Data were analysed to assess if (a) TMAO and related metabolites differed by intervention and (b) if changes in TMAO were associated with changes in Framingham 10-year risk score. Serum TMAO was lower post-intervention following MED-CONTROL compared with MED-RED intervention (post-MED-CONTROL 3·1 (sem0·2) µmv. post-MED-RED 5·0 (sem0·5) µm,P< 0·001), and decreased following MED-CONTROL (pre-v. post-MED-CONTROL,P= 0·025). Exploratory analysis using mixed model ANCOVA identified a positive association between changes in TMAO and changes in homoeostatic model assessment of insulin resistance (P= 0·036). These results suggest that lower amounts of red meat intake lead to lower TMAO concentrations in the context of a MED-EP.

Energy intake is the product of portion size (PS)—the energy content of an ingestive event—and ingestive frequency (IF)—the number of ingestive events per unit time. An uncompensated alteration in either PS or IF would result in a change in energy intake and body weight if maintained over time. The objective of this meta-analysis was to assess the independent effects of PS and IF on energy intake and body weight among healthy adults in randomized controlled trials (RCTs). A total of 9708 articles were identified in PubMed, Web of Science, Cochrane, and CINAHL databases. The articles were divided among 10 researchers; each article was screened for eligibility by 2–3 independent reviewers. Exclusion criteria included: populations 65 y, unhealthy populations (i.e. participants with an acute or chronic disease), assessments I² ≥75%). Consuming larger portion sizes was associated with higher daily energy intake [295 kcal (202, 388), n = 24; weighted mean differences (WMD) (95% CI), n = comparisons], and increased frequency of ingestive events was associated with higher energy intake [203 kcal (76, 330), n = 10]. Results from RCTs support that larger PS and greater IF are both associated with higher energy consumption. However, there is insufficient information to determine chronic effects on body weight. This protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42018104757.

The 2015–2020 Dietary Guidelines for Americans recommends adopting healthy eating patterns and restricting red meat intake, whereas the impact of consuming red meat on cardiometabolic (CMD) risk factors remains inconsistent in the scientific literature. This study assessed the effects of adding unprocessed lean red meat to a lacto-ovo vegetarian eating pattern (LOV) on changes in cardiometabolic health indexes. It was hypothesized that the addition of red meat would not influence LOV-induced improvements in CMD risk factors. Twenty-nine participants (15 female and 14 male, aged 26 ± 0.8 y, BMI 23.7 ± 0.4 kg/m²) completed this randomized-controlled, crossover trial. All participants consumed the same energy-balanced, LOV diet for two 3-week periods, separated by 5 weeks of habitual eating. Three ounces/day of unprocessed lean red meat (1.5 oz beef tenderloin and 1.5 oz pork loin) were added to the LOV diet without energy compensation for one of the two trials. Fasting blood pressure, serum lipids, lipoproteins, and glucose were measured before and at the end of each trial. Results were adjusted for age, sex, and body mass at each time point (LS Means ± SE, significance at adjusted P < 0.05). Adding unprocessed lean red meat (RM) to the LOV diet did not influence responses of the cardiometabolic health indexes after 3 weeks. Overall, significant (P < 0.05) reductions were observed for total cholesterol (without vs. with RM; −14.3 ± 3.6 vs. −14.8 ± 3.5 mg/dl), low-density lipoprotein-cholesterol (LDL-C, −8.6 ± 2.9 vs. −7.5 ± 2.9 mg/dl), and high-density lipoprotein-cholesterol (HDL-C, – 5.3 ± 1.5 vs. −4.8 ± 1.5 mg/dl). No changes were observed in fasting body mass, triglycerides, HDL-C/LDL-C ratio, glucose, or systematic/diastolic blood pressure levels. Adopting a healthy lacto-ovo vegetarian eating pattern improves serum lipids and lipoproteins within three weeks. These improvements are retained when the eating pattern becomes omnivorous by adding unprocessed lean red meat. Pork Checkoff, North Dakota Beef Commission, Beef Checkoff, and Foundation for Meat & Poultry Research & Education.

Higher red meat intake is associated with increased risk of cardiometabolic diseases, but causation of this relationships is unclear. This umbrella systematic review qualitatively assessed causality between red meat intake and cardiometabolic diseases. Two researchers independently screened and crosschecked 524 articles from MEDLINE, Scopus, Cochrane Library, and CINAHL up to November 25,2019. Articles included were systematic reviews and meta-analyses of observational or experimental studies using healthy subjects aged 19+ years; included red meat (RM) intake [total (TRM), unprocessed (URM), or processed (PRM)] as an a priori independent variable; and reported outcomes or risk factors of cardiovascular diseases (CVD) or type 2 diabetes mellitus (T2D). Causality was assessed using Bradford Hill's Causation Criteria: 1) strength (relative risk, RR ≥1.2), 2) consistency (≥67% of assessments), 3) specificity, 4) temporality, 5) biological dose-response gradient 6) plausibility, 7) coherence, 8) experimental evidence and 9) analogy. In total, 22 articles (16 with CVD data; 11 with T2D data) were included. While TRM and URM were statistically positively associated with CVD incidence and mortality, these associations were consistently weak (RR < 1.2). The strength of positive associations between TRM and T2D incidence were inconsistent while the positive associations between URM and T2D incidence were consistently weak. Results from short-term randomized controlled trials assessing effects of TRM and URM on CVD and T2D risk factors were predominately null. These experimental findings indicate a lack of coherence and need for more research to determine causality of the positive associations described above. For both CVD and T2D, temporality was established with the inclusion of prospective study designs. Researchers have proposed plausible biological mechanisms and analogies but specificity is lacking. Insufficient data precluded assessing causality between PRM and CVD or T2D; research is needed. Weakness of associations between total and unprocessed red meat intake and cardiometabolic diseases and lack of coherence with short-term experimental evidence on cardiometabolic disease risk factors reduces confidence that associations are causal. The Beef Checkoff.

Under stressful conditions such as energy restriction (ER) and physical activity, the RDA for protein of 0.8 g · kg-1 · d-1 may no longer be an appropriate recommendation. Under catabolic or anabolic conditions, higher protein intakes are proposed to attenuate the loss or increase the gain of whole-body lean mass, respectively. No known published meta-analysis compares protein intakes greater than the RDA with intakes at the RDA. Therefore, we conducted a systematic review and meta-analysis to assess the effects of protein intakes greater than the RDA, compared with at the RDA, on changes in whole-body lean mass. Three researchers independently screened 1520 articles published through August 2018 using the PubMed, Scopus, CINAHL, and Cochrane databases, with additional articles identified in published systematic review articles. Randomized, controlled, parallel studies ≥6 wk long with apparently healthy adults (≥19 y) were eligible for inclusion. Data from 18 studies resulting in 22 comparisons of lean mass changes were included in the final overall analysis. Among all comparisons, protein intakes greater than the RDA benefitted changes in lean mass relative to consuming the RDA [weighted mean difference (95% CI): 0.32 (0.01, 0.64) kg, n = 22 comparisons]. In the subgroup analyses, protein intakes greater than the RDA attenuated lean mass loss after ER [0.36 (0.06, 0.67) kg, n = 14], increased lean mass after resistance training (RT) [0.77 (0.23, 1.31) kg, n = 3], but did not differentially affect changes in lean mass [0.08 (-0.59, 0.75) kg, n = 7] under nonstressed conditions (no ER + no RT). Protein intakes greater than the RDA beneficially influenced changes in lean mass when adults were purposefully stressed by the catabolic stressor of dietary ER with and without the anabolic stressor of RT. The RDA for protein is adequate to support lean mass in adults during nonstressed states. This review was registered at www.crd.york.ac.uk/prospero as CRD 42018106532.