Plant Protein Intake Research Articles

Diet Quality, Muscle Mass, Strength and Function in Older Veterans With HIV

ObjectivesOlder adults with HIV are at a higher risk for muscle loss and physical dysfunction which may be influenced by nutritional intake. The aim of this study was to examine dietary quality and its associations with muscle mass, strength, and function in older Veterans with HIV. MethodsThis is a cross-sectional study of sedentary older Veterans with HIV aged ≥50 years. Participants were tested for grip strength (kg) over body mass index (BMI, kg/m2), gait speed (4 meters walk, m/s), and appendicular lean mass (ALM) over BMI. Dietary quality was measured by the Healthy Eating Index (HEI-2015) using data obtained from three 24-hour dietary recalls. The HEI-2015 is comprised of 13 components (e.g., vegetables, greens and beans, fruits, dairy, and proteins). Each component was scored on density out of 1000 calories and summed to a total diet quality score (0–100). The total score was divided to high (HEI > 64, top 20%) vs. low (HEI ≤ 64). Multivariable linear regressions were developed to examine the HEI-2015 and its association with each muscle measure while controlling for age (years), race/ethnicity (Non-Hispanic (NH) Blacks vs. Whites), and BMI (only in gait speed model). ResultsOverall, 40 participants with mean (±SD) age of 60.6 ± 6.5 years were included. Of those, 95% were males, 70% NH-Blacks, and mean BMI was 28.2 ± 5.3. The total dietary quality score was 52.98 ± 12.3. Most of the participants consumed sufficient proteins (87.5%) but only 50.0% included sufficient intake of seafood and plant proteins. The results indicated a lack of intake in vegetables, greens and beans, fruits, whole grain, and dairy. After adjustment, the final models showed that higher dietary quality (HEI > 64 vs. HEI ≤ 64) was associated with grip strength/BMI (β = 0.37, 95% CI: 0.02–0.71), and did not reach statistical significance with ALM/BMI (β = 0.09, 95% CI: –0.04–0.22), or with gait speed (β = 0.05, 95% CI: –0.11–0.21). ConclusionsIn this sample, older Veterans with HIV tended to have a low diet quality with insufficient intake of imperative foods which is associated with reduced muscular strength. High dietary quality might be associated with improved physical function in this population that needs to be investigated in larger and prospective studies. Funding SourcesSupported by the department of Veterans Affairs I01RX000667, I01 RX002790 and VA Advanced Fellowship Baltimore GRECC

Trends in dietary macronutrient composition and diet quality among US adults with diagnosed and undiagnosed elevated glycemic status: a serial cross-sectional study

Knowledge of glycemic status may affect dietary intake for subjects with diabetes and prediabetes. We aimed to determine whether trends of macronutrient intake and dietary quality differed by diagnosis of glycemic status among US adults with diabetes and prediabetes. Data from NHANES 1999-2016 were analyzed. Diagnosed cases were established by self-report, and undiagnosed cases were defined by laboratory criteria (glycated hemoglobin≥5.7%, fasting plasma glucose ≥ 100mg/dL, or 2-h oral-glucose-tolerance test ≥ 140mg/dL). A difference-in-differences model was used to compare the temporal trends between the 2 groups. There were 7502 diagnosed and 12,974 undiagnosed cases with elevated glycemic status included in the study. During 1999-2016, the intake of low-quality carbohydrates was lower, whereas intakes of high-quality carbohydrates, animal protein, plant protein, and unsaturated fat and the Healthy Eating Index 2015 (HEI-2015) score were higher, among the diagnosed cases than among the undiagnosed cases (P<0.001 for all). However, in the trend analyses from 1999 to 2016, the increase in intake of high-quality carbohydrates was smaller among the diagnosed cases than among the undiagnosed cases (difference: -1.16%; 95% CI: -1.82%, -0.50%; P=0.001). Moreover, the decrease in low-quality carbohydrate intake was smaller (difference: 0.79%; 95% CI: 0.01%, 1.57%; P=0.05) and the increase in saturated fat intake was larger (difference: 0.44%; 95% CI: 0.08%, 0.79%; P=0.02) among the diagnosed cases than among the undiagnosed cases. A significant difference of temporal trends in the HEI-2015 score between the diagnosed and undiagnosed cases was also observed, in favor of the undiagnosed cases (difference: -2.56; 95% CI: -3.71, -1.41; P<0.001). Although dietary habits among adults with diagnosed diabetes and prediabetes were better than those among the undiagnosed cases, these advantages have been diminishing during the past 2 decades.

The relationship between plant and animal based protein with semen parameters: A cross-sectional study in infertile men.

Infertility is a global challenge, affecting 15% of non-contracepting couples that have intercourse. Recent studies have shown that diet can directly affect sperm quality. Protein is one of the most important components of an adequate diet that can regulate metabolic profile and send signals to the reproductive axis. This study aimed to determine the relationship between plant and animal protein intake and infertility in Iranian men. In this cross-sectional study, 270 infertile men aged 18-55 years were selected from Isfahan Infertility clinic in 2018. Semen assessment was performed according to the fifth edition of the WHO laboratory manual and a 168-item questionnaire was used to determine the amount of dietary intakes of participants. Statistical analyses were carried out using SPSS for Windows software (version 20.0), SPSS Inc, and Chicago IL. P-value < 0.05 was considered statistically significant. There was significant association between concentration and plant protein tertiles in the crude model (OR=0.38; 95% CI: 0.19, 0.75; P=0.004), which became significant in the both adjusted model and participants in highest tertile had a lower risk (OR=0.36; 95% CI: 0.18, 0.72; P=0.003 and OR=0.31; 95% CI: 0.14, 0.65; P=0.002). Also, there was a significant association between sperm concentration and animal protein in the crude model, and participants in the highest tertile had a higher risk (OR=2.32; 95% CI: 1.13, 4.76; P=0.02). Participants in highest animal protein tertile had a higher risk (OR=2.38; 95% CI: 1.16, 4.91; P=0.02 and OR=2.42; 95% CI: 1.13, 5.19; P=0.02) in adjusted model. Furthermore, there was a significant association between morphology and animal protein in the crude model, and participants in the highest tertile had a higher risk (OR=3.68; 95% CI: 0.97, 13.91; P=0.04). In this cross-sectional study, the relationship between plant and animal protein with semen parameters was evaluated. Although this study demonstrated the relationship between plant and animal based protein with semen parameters, more researches need to be done in this area.

Association of Dietary Protein Intake and Grip Strength Among Adults Aged 19+ Years: NHANES 2011-2014 Analysis.

BackgroundResearch on the role of protein in the diet has evolved beyond a focus on quantity to include the impact of its quality and distribution across meal times in an effort to optimize dietary protein recommendations.ObjectiveTo determine the association of dietary protein amount, type, and intake pattern with grip strength in adults.DesignData from the National Health and Nutrition Examination Survey (NHANES) 2011–2014 for adults 19 + years (N = 9,214) were used with exclusions for pregnant and lactating women. Intakes of dietary total protein (TP), animal protein (AP, including dairy), plant protein (PP), and leucine (Leu) were determined using day 1 24 h dietary recall data after adjusting for the complex sample design of NHANES. Regression analyses were used to assess the association of dietary protein and leucine intake quartiles, and whether consuming > 20 g of dietary protein at one or more meals was related to grip strength with adjustment for age, gender, and ethnicity.ResultsMean intake of TP among adults aged 19 + years was 83.6 ± 0.5 g/day, and 2/3rd of this was from animal sources (including dairy). Grip strength increased (p < 0.05) with increasing quartiles of TP, AP, PP, and leucine among all adults 19 + years (β = 1.340.19, 1.27 ± 0.19, 0.76 ± 0.20, and 1.33 ± 0.23, respectively), 19–50 years (β = 1.14 ± 0.27, 1.06 ± 0.25, 0.77 ± 0.30, and 1.18 ± 0.27, respectively), and 51 + years (β = 0.95 ± 0.26, 1.08 ± 0.27, and 1.05 ± 0.27, respectively, for TP, AP, and Leu); however, the increase was more pronounced for AP than PP. Grip strength also increased (p < 0.05) with increasing the number of meal occasions containing > 20 g of dietary protein (β = 1.50 ± 0.20, 1.41 ± 0.25, and 0.91 ± 0.37 for 19+, 19–50, and 51 + years, respectively), and significant increases were detected for two meals compared to zero meals.ConclusionDietary protein quantity, quality, and distribution should be considered collectively when looking to optimize protein intake to support muscle strength and function.

Diet Quality and Food Intakes samong US Adults by Level of Animal Protein Intake, What We Eat in America, NHANES 2015–2018

BackgroundDietary recommendations encourage consuming protein from a variety of plant and animal sources. Evaluating the diet of US adults by level of animal protein (AP) intake can inform dietary assessment and nutrition education. ObjectivesThe objective of this cross-sectional study was to estimate percentage of total protein intake from animal sources by US adults to compare diet quality, and intake from USDA Food Patterns (FP) groups by quintiles of AP. MethodsOne day dietary intake data from adults 20+ y (N = 9566) in What We Eat in America (WWEIA), NHANES 2015–2018 were used. Proportions of total protein intake from animal and plant sources and the USDA FP groups were estimated from the ingredients in the Food and Nutrient Database for Dietary Studies 2015–2018, then applied to the dietary intakes. The 2015 Healthy Eating Index (HEI) was used as an indicator of diet quality. The USDA FP groups were used to describe the contribution of animal and plant foods to total protein intake. Data were analyzed by quintile (Q) of AP protein intake; comparisons were made using pairwise t-tests with adjustments for covariates using survey sample weights. Results were considered significant at P <0.001. ResultsTotal mean protein intakes ranged from 62 (Q1) to 104 g (Q5) (all comparisons P <0.001). Total HEI score (possible 100) of Q1 was slightly higher (54.2) (P <0.001) compared with Q1–Q4 (range: 48.0–50.3), which did not differ significantly from each other. Contributions of plant FP components to total protein intake of Q1 to Q5, respectively, were 15% to 1% from nuts/seeds, legumes, and soy products combined; 35 to 10% from grains. The contribution of animal FP components were 19–66% from meat/poultry/seafood, 14–19% dairy, and 3–5% eggs. ConclusionsThe intake of foods considered to be good sources of plant protein was low. The overall diet quality of all adults was suboptimal regardless of plant protein intake.

Determination of the Effects of Duodenal Infusion Soy Protein Hydrolysate on Hepatic Glucose and Lipid Metabolism in Pigs Through Multi-Omics Analysis.

High animal protein intake increases hepatic lipid deposition and the risk of diabetes. However, the effects of high plant protein (HPP) intake on glycaemic responses and hepatic lipid metabolism in healthy people, as well as the underlying mechanisms, remain unclear. The current study explored the metabolomic and transcriptomic responses in the livers of pigs to assess the effects of HPP intake on host glucose and lipid metabolism. Sixteen pigs were infused with sterile saline or soy protein hydrolysate (SPH; 70 g/day) through a duodenal fistula twice daily during a 15 days experimental period. Hepatic metabolomic and transcriptomic analyses were performed, and the serum and hepatic biochemical parameters were measured. The results revealed that SPH infusion decreased serum glucose, hepatic triglyceride (TG), total cholesterol and low-density lipoprotein cholesterol levels, while it increased serum urea and eight hepatic amino acid levels (P < 0.05). Hepatic metabolomics displayed that SPH treatment produced seven different metabolites, four of which were related to lipid metabolism and one was related to glucose metabolism. In particular, lower (P < 0.05) glycocholic acid and glucose 1-phosphate levels and higher (P < 0.05) phosphatidylethanolamine (PE), arachidonic acid, prostaglandin F2α, l-carnitine and indole-3 acetic acid levels were observed following SPH infusion. A further metabolic pathway enrichment analysis found that these differential metabolites were mainly enriched in pathways related to lipid and glucose metabolism. Hepatic transcriptomics also demonstrated that multiple genes related to glucose and lipid metabolism were affected by SPH (P < 0.05). Together, SPH infusion reduced the hepatic TG levels by accelerating fatty acid β-oxidation and inhibiting TG synthesis. In addition, SPH infusion reduced the serum glucose levels by promoting hepatic glucose uptake and glycolysis. This study's result demonstrated that HPP intake regulated glycaemic responses and hepatic lipid metabolism in pigs without increasing the risk of hepatic lipid deposition and hyperglycaemia.

Association of animal and plant protein intakes with biomarkers of insulin and insulin-like growth factor axis

Insulin and insulin-like growth factor (IGF)-1 signaling is a proposed mechanism linking dietary protein and major chronic diseases. However, it is unclear whether animal and plant proteins are associated with biomarkers of insulin and IGF axis. We analyzed a total of 14,709 participants from Nurses' Health Study and Health Professionals Follow-up Study who had provided a blood sample. Detailed dietary information was assessed using validated food frequency questionnaires. We assessed C-peptide, insulin, IGF-1, and IGF binding proteins (BP). Multivariable-adjusted linear regressions were used to examine associations of animal and plant protein intake with biomarkers after adjusting for confounders. The medians (5th-95th percentiles) of animal and plant protein intake (% of total energy) were 13% (8-19%) and 5% (4-7%), respectively. Compared to participants in the lowest quintile, those in the highest quintile of animal protein had 4.8% (95% CI: 1.9, 7.9; P-trend<0.001) higher concentration of IGF-1 and -7.2% (95% CI:-14.8, 1.1; P for trend=0.03) and-11.8% (95% CI:-20.6,-1.9; P-trend<0.001) lower concentration of IGFBP-1 and IGFBP-2, respectively, after adjustment for major lifestyle factors and diet quality. In contrast, no association was observed between animal protein intake and C-peptide, insulin and IGFBP-3. The associations were restricted to participants with at least one unhealthy lifestyle risk factor (i.e., overweight/obese, physical inactivity, smoking, and heavy alcohol intake). Plant protein tended to be strongly associated with numerous biomarkers in age-adjusted analyses but these became largely attenuated or non-significant in multivariable adjustment. Plant protein intake remained positively associated with IGF-1 (P-trend=0.002) and possibly IGFBP-1 (P-trend=0.02) after multivariable adjustment. Substitution of plant protein with animal protein sources was associated with lower IGFBP-1. In additional analysis, IGF-1 and IGFBPs were estimated to mediate approximately 5-20% of the association between animal protein and type 2 diabetes. Higher animal protein intake was associated with higher IGF-1 and lower IGFBP-1 and IGFBP-2, whereas higher plant protein intake was associated with higher IGF-1 and IGFBP-1.

Dietary intake of animal and plant proteins and risk of all cause and cause-specific mortality: The Epic-Italy cohort

BACKGROUND: To examine the associations of animal and plant protein intake with all-cause, cardiovascular and cancer mortality risk in middle-aged Italian men and women with substantially lower animal protein intake than North Americans. METHODS AND RESULTS: Food consumption was assessed by validated Epic semiquantitative FFQs. Multivariable Cox models stratified by center, age, and sex, and adjusted for confounders, estimated associations of animal and plant protein consumption with mortality for all causes, cardiovascular disease, and cancer. After a median follow-up of 15.2 years, 2,449 deaths were identified in 45,009 participants. No significant association between intake of total, animal or plant protein and mortality was found in the fully adjusted models. Substitution of plant protein for animal protein was inversely associated with cardiovascular mortality (HR, 0.47; 95% CI, 0.24–0.92) only in people with at least 1 unhealthy lifestyle risk factor and poor adherence to a Mediterranean diet. Participants in the highest quintile group of animal protein intake had higher glucose, total and LDL cholesterol levels than those in the lowest quintile. In contrast, higher plant protein intake was negatively associated with fasting insulin and cholesterol, despite higher BMI, physical inactivity and starch consumption. CONCLUSIONS: Replacing plant protein for animal protein was associated with lower cardiovascular mortality among individuals with unhealthy lifestyle risk factors. High animal but not plant protein intake is associated with impaired fasting glucose and hypercholesterolemia, despite lower calorie and carbohydrate intake, suggesting that protein source plays crucial roles in modulating cardiometabolic health independently of body weight.

An evaluation of the serum carbon isotope ratio as a candidate predictive biomarker of the dietary animal protein ratio (animal protein/total protein) in a 15-day controlled feeding study of US adults

The serum natural abundance carbon isotope ratio (CIR) was recently identified as a candidate biomarker of animal protein intake in postmenopausal women. Such a biomarker would help clarify the relation between dietary protein source (plant or animal) and chronic disease risk. We aimed to evaluate the performance of the serum CIR as a biomarker of dietary protein source in a controlled feeding study of men and women of diverse age and BMI. We conducted a 15-d feeding study of 100 adults (age: 18-70 y, 55% women) in Phoenix, AZ. Participants were provided individualized diets that approximated habitual food intakes. Serum was collected at the end of the feeding period for biomarker measurements. Median [IQR] animal protein intake was 67 g/d [55-88 g/d], which was 64% of total protein. The serum CIR was positively correlated with animal protein and inversely correlated with plant protein intake, leading to a strong correlation (r2=0.76) with the dietary animal protein ratio (APR; animal/total protein). Regressing serum CIR on the APR, serum nitrogen isotope ratio (NIR), gender, age, and body weight generated an R2 of 0.78. Following the measurement error model for predictive biomarkers, the resulting regression equation was then inverted to develop a calibrated biomarker equation for APR. Added sugars ratio (added/total sugars intake) and corn intakes also influenced the serum CIR but to a much lesser degree than the APR; variations in these intakes had only small effects on biomarker-estimated APR. Based on our findings in this US cohort of mixed sex and age, we propose the serum CIR alongside NIR as a predictive dietary biomarker of the APR. We anticipate using this biomarker to generate calibrated estimates based on self-reported intake and ultimately to obtain more precise disease risk estimates according to dietary protein source.

Protein intake and risk of frailty among older women in the Nurses' Health Study

BackgroundThere is evidence that an overall healthy diet is associated with lower risk of frailty. However, the effect of diet composition, specifically the role of protein intake on frailty, is mostly unclear. The aim of this study was to evaluate the intake of protein, including total, plant, animal, and dairy protein, in relation to frailty incidence in a large cohort of older women.MethodsWe analysed data from 85 871 women aged ≥60 participating in the Nurses' Health Study. Intake of protein was measured nine times during follow‐up from 1980 until 2010. Frailty was defined as having at least three of the following five criteria from the Fatigue, Resistance, Ambulation, Illnesses and Loss of Weight (FRAIL) scale: fatigue, low strength, reduced aerobic capacity, having ≥5 illnesses, and weight loss of ≥5%. The occurrence of frailty was assessed every 4 years from 1992 up to 2014.ResultsDuring follow‐up, we identified 13 279 incident cases of frailty. Women with a higher intake of plant protein had a lower risk of developing frailty after adjustment for all relevant confounders [relative risks across quintiles of consumption: 1.00, 0.94, 0.89, 0.86, and 0.86; P‐trend < 0.001]. In contrast, those with a higher intake of animal protein intake had a higher risk of frailty [relative risks across quintiles of consumption: 1.00, 0.98, 0.99, 1.00, and 1.07; P‐trend 0.04]. The intake of total and dairy protein showed no significant association with frailty in the full model. Substituting 5% of energy from plant protein intake at the expense of animal protein, dairy protein, or non‐dairy animal protein was associated with 38% (29%, 47%), 32% (21%, 42%), and 42% (33%, 50%) reduced risk of frailty.ConclusionsA higher intake of plant protein, but not animal or dairy protein, was associated with a lower risk of frailty. Substitution of plant protein for animal protein, especially non‐dairy animal protein, was associated with lower risk of frailty.

Evaluating type and amount of dietary protein in relation to metabolic syndrome among Iranian adults: cross-sectional analysis of Fasa Persian cohort study

Background and aimMetabolic syndrome is characterized by several conditions including abdominal obesity, dyslipidemia, impaired glucose levels, and hypertension; which all are directly associated with an increased risk of cardiovascular disease and type 2 diabetes mellitus. This study aimed to evaluate the association of the amount and source of dietary protein with the risk of metabolic syndrome and its components in adult men and women.Material and methodThis study was performed using Persian cohort data, Fasa branch, which included 3660 men and 5262 women. Individuals were divided into five groups for total dietary proteins, plant proteins, and animal proteins using the quintiles, and the odds of incidence for metabolic syndrome and each component was evaluated.ResultsA higher intake of total protein was associated with lower odds of having metabolic syndrome (OR: 0.24 95% CI 0.18–0.33, P-trend < 0.001 in men, OR: 0.42 95% CI 0.34–0.51, P-trend < 0.001 in women) and all of its components. men (OR: 0.35 95% CI 0.25–0.48, P-trend < 0.001) and women (OR: 0.41 95% CI 0.33–0.52, P-trend < 0.001) in the highest quintile of plant protein intake had a reduced prevalence of metabolic syndrome and its components. An increased animal protein intake was associated with a lower prevalence of metabolic syndrome (P-trend < 0.001), a declined risk of having elevated triglycerides (P-trend = 0.016) in men, and a reduced risk of having abdominal obesity in men (P-trend < 0.001) and women (P-trend < 0.001).ConclusionA higher consumption of total protein and plant protein was associated with a lower prevalence of metabolic syndrome and its components. Increased consumption of animal protein seemed to be related to a lower prevalence abdominal obesity. Also, only in men, animal protein was associated with decreased risk of having metabolic syndrome.

Association between Protein Intake and the Risk of Hypertension among Chinese Men and Women: A Longitudinal Study.

This study aimed to examine the relationship between hypertension risk and protein intake in Chinese individuals. Our analysis included 7007 men and 7752 women from 9 China Health and Nutrition Survey waves (1991–2015). The main outcome was incident hypertension. Dietary intake was recorded using a combination of 3 consecutive 24-h recalls and a household food inventory survey. Energy-adjusted cumulative average intakes were analyzed, and Cox proportional hazards regression models were built. After 143,035 person-years of follow-up, 2586 and 2376 new male and female hypertension cases were identified, respectively. In multivariate-adjusted models with dietary protein intakes included as categorical variables, higher animal protein intake was associated with lower hypertension risk in women (p-trend = 0.01), whereas non-significant in men. Plant protein intake showed a significant positive correlation with hypertension risk, while non-significant for total protein. On a continuous scale, restricted cubic spline curves visually revealed L-, J-, and U-shaped associations between hypertension risk and animal-, plant-, and total-protein intakes, respectively, in both sexes (all p-nonlinearity < 0.0001). Our results suggest a beneficial association between intakes of animal, plant, and total proteins and hypertension risk at lower intake levels, and excessive intake of plant or total protein may increase the hypertension risk in the Chinese population.

Dietary Protein Source Matters for Changes in Inflammation Measured by Urinary C-Reactive Protein in Rural Polish Women.

Multiple macronutrients have been shown to affect systemic inflammation, a well-known predictor of chronic disease. Less often, varying sources of these macronutrients are examined. Different subsistence environments lead to varying access to protein sources which, combined with physical activity patterns, may lead to different relationships than among more typically studied sedentary, industrialized populations. This study hypothesizes an association between dietary protein intake and urinary C-Reactive Protein (CRP) concentration in women from a rural, agrarian Polish community. We assessed protein intake and their sources for 80 nonsmoking, premenopausal Polish women who were not pregnant, nursing, or on hormonal birth control during the study or within the previous six months. Each participant completed multiple 24-hour dietary recalls during one menstrual cycle. Participants collected morning void urinary samples daily over one menstrual cycle for urinary CRP analysis. We analyzed relationships between plant and animal protein intake and CRP over the menstrual cycle by multiple linear regression. Plant protein in cereal foods was significantly positively associated with cycle-average urinary CRP concentrations (p<0.05) after controlling for body fat percent, total energy intake, and dietary fiber. Foods containing animal protein were not significantly associated with CRP. Contents of this population's main plant and animal protein sources differ from those of more commonly studied industrialized populations. Within the context of a population's typical diet, more emphasis may need to be placed on particular source of protein consumed, beyond plant versus animal, in order to understand relationships with CRP.

Total, animal, and plant protein intake and pneumonia mortality in the Japan Public Health Center–based Prospective Study

The association between total protein intake and all-cause mortality is inconsistent. Pneumonia is a major cause of death among the elderly, and the association between protein intake and pneumonia mortality warrants clarification. We aimed to examine the association between total, plant, and animal protein intake and pneumonia mortality in a prospective design. The Japan Public Health Center (JPHC)-based Prospective Study prospectively follows 83,351 participants (37,652 men and 45,699 women). Total, plant, and animal protein intakes were calculated from a validated food-frequency questionnaire. A Cox hazards model was used to calculate HRs and 95% CIs, with adjustment for confounding factors. During ∼18.4 y of follow-up, 990 pneumonia deaths (634men and 356 women) were observed. In the multivariable-adjusted model and in the model further adjusted for fatty acid intake, increase in total protein intake was marginally significantly associated with lower pneumonia mortality in women [lowest vs. highest quartile, HR (95% CI): 0.71 (0.53, 0.97), P-trend = 0.01 in the multivariable-adjusted model, and 0.70 (0.45, 1.06), P-trend = 0.05 in the fatty acid intake-adjusted model]. Total protein intake in men and animal and plant protein intake in both men and women were not significantly associated with pneumonia mortality in the fatty acid-adjusted model. Although the HR in the highest quartile was not significant and further research to determine the upper limit of recommended protein intake is required, higher total protein intake was associated with lower pneumonia mortality in women.

Update on Plant-Based Diets and Cardiometabolic Risk.

The number of published studies on the health effects of plant-based diets has increased dramatically in the last decade. The purpose of this narrative review is to update the most recent evidence from large prospective cohort studies and meta-analyses on the effects of plant-based dietary patterns on cardiovascular outcomes and risk factors and total mortality. Most new data from large prospective cohort studies carried out in the USA, Europe, and Asia continue to show inverse associations between plant-based diets and the incidence of ischemic heart disease and stroke, while less data exist for heart failure incidence. New analyses suggest that only some components of plant-based diets are associated with cardiovascular benefit. Recent meta-analyses show inverse associations between plant-protein intake and all-cause mortality, although heterogeneity exists, and small mortality risks from some animal proteins, notably processed meats. New studies continue to demonstrate small but favorable effects of plant-based diets on traditional risk factors and suggest other emerging mechanisms by which plant-based diets exert cardiovascular benefits. The recommendation to consume a plant-based diet to reduce cardiovascular risk remains an evidence-based strategy based on observational studies. New data highlight the importance of ensuring that these diets are nutrient-rich and low in plant foods associated with signals of harm. For this reason, assessment of diet quality is important even in patients who report adherence to plant-based diets. Large randomized trials with hard cardiovascular endpoints might strengthen this evidence-base, but feasibility is limited.

Protein intake in children and growth and risk of overweight or obesity: A systematic review and meta-analysis.

ObjectivesThe aim of this study was to examine the evidence for an association between the dietary protein intake in children and the growth and risk of overweight or obesity up to 18 years of age in settings relevant for the Nordic countries.MethodsWe searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Scopus up to February 26, 2021 for randomized controlled trials (RCTs) or prospective cohort studies assessing for protein intake from foods (total and from different sources) in children. The outcomes include weight, height/length, adiposity indices, and/or risk of overweight and/or obesity. The risk of bias was evaluated with instruments for each respective design (Cochrane’s Risk of Bias 2.0 and RoB-NObS). A meta-analysis of five cohort studies was performed. The evidence was classified according to the criteria of the World Cancer Research Fund.ResultsThe literature search resulted in 9,132 abstracts, of which 55 papers were identified as potentially relevant. In total, 21 studies from 27 publications were included, of which five were RCTs and 16 were cohort studies. The RCTs found generally null effects of high-protein intake in infants on weight gain, nor that lower protein diets negatively affected growth. All included RCTs had some concern regarding the risk of bias and were limited by small sample sizes. Total protein intake and BMI were assessed in 12 cohorts, of which 11 found positive associations. The meta-analysis revealed a pooled effect estimate of 0.06 (95% CI 0.03, 0.1) kg/m2 BMI per one E% increment in total protein (I2 = 15.5). Therefore, the evidence for a positive relationship between total protein intake and BMI was considered probable. Furthermore, there was probable evidence for an association between higher intake of animal protein and increased BMI. There was limited, suggestive evidence for an effect of total protein intake and higher risk of overweight and/or obesity, while no conclusions could be made on the associations between animal vs. plant protein intake and risk of overweight and/or obesity.DiscussionIn healthy, well-nourished children of Western populations, there is probably a causal relationship between a high-protein intake in early childhood (≤ 18 months) – particularly protein of animal origin – and higher BMI later in childhood, with consistent findings across cohort studies. A lack of RCTs precluded a stronger grading of the evidence.

Plasma Metabolites Associated with a Protein-Rich Dietary Pattern: Results from the OmniHeart Trial.

ScopeLack of biomarkers is a challenge for the accurate assessment of protein intake and interpretation of observational study data. The study aims to identify biomarkers of a protein‐rich dietary pattern.Methods and ResultsThe Optimal Macronutrient Intake Trial to Prevent Heart Disease (OmniHeart) trial is a randomized cross‐over feeding study which tested three dietary patterns with varied macronutrient content (carbohydrate‐rich; protein‐rich with about half from plant sources; and unsaturated fat‐rich). In 156 adults, differences in log‐transformed plasma metabolite levels at the end of the protein‐ and carbohydrate‐rich diet periods using paired t‐tests is examined. Partial least‐squares discriminant analysis is used to identify a set of metabolites which are influential in discriminating between the protein‐rich versus carbohydrate‐rich dietary patterns. Of 839 known metabolites, 102 metabolites differ significantly between the protein‐rich and the carbohydrate‐rich dietary patterns after Bonferroni correction, the majority of which are lipids (n = 35), amino acids (n = 27), and xenobiotics (n = 24). Metabolites which are the most influential in discriminating between the protein‐rich and the carbohydrate‐rich dietary patterns represent plant protein intake, food or beverage intake, and preparation methods.ConclusionsThe study identifies many plasma metabolites associated with the protein‐rich dietary pattern. If replicated, these metabolites may be used to assess level of adherence to a similar dietary pattern.

Health- or Environment-Focused Text Messages as a Potential Strategy to Increase Plant-Based Eating among Young Adults: An Exploratory Study.

Previous plant-based diet (PBD) adoption strategies have primarily focused on health rather than environmental rationale and meat reduction rather than plant-based protein promotion. In this study, we explored the effect of a theory-informed text-message intervention on dietary intentions and behaviors in young adult omnivores and the potential explanatory role of PBD beliefs, subjective norm, self-efficacy, moral norm, and health and environmental values. Participants completed baseline questionnaires and reported dietary intake before being randomly assigned to receive 2–3 health- or environment-focused text messages per week for eight weeks and then repeated baseline assessments. Although we did not see significant changes in meat or plant protein intake, we did observe a marked decrease in intentions to consume animal protein and a marginal increase in fruit and vegetable consumption intention. We identified subjective norms, self-efficacy, and moral satisfaction as the strongest predictors of changes in intention to consume animal or plant protein. Although few group differences were observed, those receiving environment-focused text messages experienced a greater change in values and were more likely to increase vegetable intake. Messages that improve sustainability awareness and provide practical adoption strategies may be part of an effective strategy to influence PBD intake among young adults.

Animal Protein Intake Is Inversely Associated With Mortality in Older Adults: The InCHIANTI Study.

In general, plant protein intake was inversely associated with mortality in studies in middle-aged adults. Our aim was to evaluate the long-term associations of animal and plant protein intake with mortality in older adults. A prospective cohort study including 1 139 community-dwelling older adults (mean age 75 years, 56% women) living in Tuscany, Italy, followed for 20 years (InCHIANTI study) was analyzed. Dietary intake by food frequency questionnaires and clinical information were assessed 5 times during the follow-up. Protein intakes were expressed as percentages of total energy. Time-dependent Cox regression models adjusted for confounders were used to assess the association between plant and animal protein intake, and mortality. During the 20 years of follow-up (mean: 12 years), 811 deaths occurred (292 of cardiovascular- and 151 of cancer-related causes). Animal protein intake was inversely associated with all-cause (hazard ratio [HR] per 1% of total energy from protein increase, 95% confidence interval [CI]: 0.96, 0.93-0.99) and cardiovascular mortality (HR per 1% of total energy from protein increase, 95% CI: 0.93, 0.87-0.98). Plant protein intake showed no association with any of the mortality outcomes, but an interaction with baseline hypertension was found for all-cause and cardiovascular mortality (p < .05). Animal protein was inversely associated with all-cause and cardiovascular mortality in older adults. Further studies are needed to provide recommendations on dietary protein intake for older adults.

Associations between dietary intake of total protein and sources of protein (plant vs. animal) and risk of all-cause and cause-specific mortality in older Australian men: The Concord Health and Ageing in Men Project.

The association between dietary protein intake and the risk of mortality is still controversial. The present study aimed to examine the associations between dietary total, animal and plant protein intake and all-cause and cause-specific mortality. Community-dwelling men aged ≥70 years were recruited from local government areas surrounding Concord Hospital in Sydney, New South Wales for the Concord Health and Ageing in Men Project (CHAMP). The research dietitian administered a standardised validated diet history questionnaire to capture baseline dietary intake. In total, 794 men participated in a detailed diet history interview at the third wave. Adequacy of protein intake was assessed by comparing participant intake with the Nutrient Reference Values. Total protein intake was categorised into quintiles. Sources of protein were also captured. Mortality was ascertained through the New South Wales death registry. Cox proportional hazard models were used to assess the association between dietary total, animal and plant protein intake and risk of mortality. The mean age of the CHAMP men was 81 years. In total, 162 men died during a median follow-up of 3.7years. Of these, 54 (33.3%) and 49 (30.2%) men died due to cancer and cardiovascular disease, respectively. There were U-shaped associations between protein intake and all-cause and cancer mortality. In multiple adjusted analysis, the second (hazard ratio [HR]=0.38; 95% confidence interval [CI]=0.18-0.82) and third (HR=0.36; 95% CI=0.16-0.82) quintiles of protein intakes were significantly associated with reduced risk of all-cause and only second quintile (HR=0.47; 95% CI=0.10-0.93) of protein intake was significantly associated with cancer mortality. Each serve increase in animal protein was significantly associated with 12% (HR=1.12; 95% CI=1.00-1.26) and 23% (HR=1.23; 95% CI=1.02-1.49) increased risk of all-cause mortality and cancer mortality respectively. Conversely, each serve increase in plant protein intake was significantly associated with 25% (HR=0.75; 95% CI 0.61-0.92) and 28% (HR=0.72; 95% CI=0.53-0.97) reduced risk of all-cause and cancer mortality, respectively. No such associations were observed for cardiovascular disease mortality. Both second and third quintiles of total protein intake were associated with reduced all-cause and cancer mortality. Plant protein was inversely associated with all-cause and cancer mortality, whereas animal protein intake was positively associated with mortality.