Dietary intake of total, animal and plant proteins and the risk of coronary heart disease and hypertension: a systematic review and dose-response meta-analysis of prospective cohort studies

Dietary protein and blood pressure: an umbrella review of systematic reviews and evaluation of the evidence

INTRODUCTION

This umbrella review aimed to investigate the evidence of an effect of dietary intake of total protein, animal and plant protein on blood pressure (BP), and hypertension (PROSPERO: CRD42018082395).

METHODS

PubMed, Embase and Cochrane Database were systematically searched for systematic reviews (SRs) of prospective studies with or without meta-analysis published between 05/2007 and 10/2022. The methodological quality and outcome-specific certainty of evidence were assessed by the AMSTAR 2 and NutriGrade tools, followed by an assessment of the overall certainty of evidence. SRs investigating specific protein sources are described in this review, but not included in the assessment of the overall certainty of evidence.

RESULTS

Sixteen SRs were considered eligible for the umbrella review. Ten of the SRs investigated total protein intake, six animal protein, six plant protein and four animal vs. plant protein. The majority of the SRs reported no associations or effects of total, animal and plant protein on BP (all "possible" evidence), whereby the uncertainty regarding the effects on BP was particularly high for plant protein. Two SRs addressing milk-derived protein showed a reduction in BP; in contrast, SRs investigating soy protein found no effect on BP. The outcome-specific certainty of evidence of the SRs was mostly rated as low.

DISCUSSION/CONCLUSION

This umbrella review showed uncertainties whether there are any effects on BP from the intake of total protein, or animal or plant proteins, specifically. Based on data from two SRs with milk protein, it cannot be excluded that certain types of protein could favourably influence BP.

Animal- and Plant-Based Protein Sources: A Scoping Review of Human Health Outcomes and Environmental Impact

Dietary proteins are indispensable to human nutrition. In addition to their tissue-building function, they affect body composition and regulate various metabolic pathways, as well as satiety and immune system activity. Protein use can be examined from a quantitative or qualitative viewpoint. In this scoping review, we compare animal- and plant-based protein sources in terms of their effects on human health and the environment. We conclude that the consumption of vegetable protein sources is associated with better health outcomes overall (namely, on the cardiovascular system) than animal-based product use. The healthier outcomes of vegetable protein sources dovetail with their lower environmental impact, which must be considered when designing an optimal diet. Indeed, the health of the planet cannot be disjointed from the health of the human being. Future research will clarify the mechanisms of action underlying the health effects of plant-based protein sources when compared with animal sources, fostering better agronomic practices and influencing public health in a direction that will benefit both the planet and its inhabitants.

Dietary total, plant and animal protein intake in relation to metabolic health status in overweight and obese adolescents

Few studies have investigated dietary total protein intake and its subtypes in relation to metabolic health status. We explored the relation between dietary total, plant and animal protein intake with metabolic health status in Iranian overweight/obese adolescents. Overweight/obese adolescents (n = 203) were selected for this cross-sectional study by multistage cluster random-sampling method. A validated food frequency questionnaire was used to evaluate dietary intakes. Total, plant and animal protein intake were considered as percentage of energy intake. Anthropometric indices, blood pressure, lipid and glycemic profiles were collected. Participants were classified as metabolically healthy obese (MHO) or unhealthy obese (MUO) based on International Diabetes Federation (IDF) and IDF/Homeostasis Model Assessment Insulin Resistance (HOMA-IR) definitions. Subjects had a mean age of 13.98 years, and 50.2% of them were girls. Based on IDF criteria, adolescents in the top tertile of total (OR = 0.32; 95% CI 0.13–0.77), plant (OR = 0.30; 95% CI 0.10–0.91), and animal (OR = 0.20; 95% CI 0.08–0.54) protein intake had lower odds of being MUO compared to the reference category. Considering IDF/HOMA-IR criteria, subjects in the highest tertile of total (OR = 0.31; 95% CI 0.12–0.79) and animal (OR = 0.17; 95% CI 0.06–0.49) protein intake were less likely to be MUO. However, no substantial association was observed with plant protein intake. Also, an inverse association was observed between each SD increase in total and animal protein with MUO odds. We found inverse association between total, plant and animal protein intake and chance of being MUO in adolescents. Further prospective studies are needed to confirm the findings.

Exploration of walnut components and their association with health effects

Traditionally, walnuts have occupied an imperative position in the functional food market with consistently recognized nutritious and functional properties. In the past years, the lipid profile of walnuts has brought much scientific attention via linking a cascade of biological attributes and health-promoting effects. Over time, researchers have focused on diversified composition (polyphenols and vitamins) of different parts of walnut (flower, pellicle, and kernel) and emphasized their physiological significance. Consequently, a plethora of reports has emerged on the potential role of walnut consumption against a series of diseases including cancer, gut dysbiosis, cardiovascular, and neurodegenerative diseases. Therefore, we accumulated the updated data on composition and classification, extraction methods, and utilization of different parts of walnuts as well as associated beneficial effects under in vivo and clinical studies. Altogether, this review summarized the ameliorative effects of a walnut-enriched diet in chronic diseases which can be designated to the synergistic or individual effects of walnut components mainly through anti-oxidative and anti-inflammatory role.