Madeleine Myers

Hen’s eggs (from Gallus gallus domesticus) provide choline, folate, vitamin D, iodine, B vitamins and high-quality protein and are no longer viewed by national bodies as a risk factor for hypercholesterolaemia and cardiovascular disease (CVD). Yet, questions remain about the benefits and risks of eating eggs regularly. This review evaluates recent high-quality evidence from randomised controlled trials (RCT) and meta-analyses of observational studies and considers new areas of interest, such as weight management, protein metabolism, allergy risk and sustainability. In several RCT, eggs increased muscle protein synthesis and lowered fat mass, which could support optimal body composition. Eggs within a meal improved satiety, which could translate into lower energy intakes, although more RCT are needed. In observational studies, higher egg consumption was associated with a null effect or a modest reduced risk of CVD. For type 2 diabetes (T2D) incidence and risk of CVD in people with T2D, there were inconsistencies between observational and RCT data, with the former noting positive associations and the latter seeing no effect of higher egg intake on markers of T2D and CVD. Sustainability metrics suggest that eggs have the lowest planetary impact amongst animal proteins. To lower allergy risk, earlier introduction of eggs into weaning diets is warranted. In conclusion, the balance of evidence points to eggs being a nutritious food suggesting there are broad health benefits from including eggs in the diet at intakes higher than that currently consumed by European populations.

Dietary guidelines often deal with 100% fruit juice (FJ) inconsistently because it represents a source of free sugars. However, FJ also provides bioavailable micronutrients and plant bioactives at levels similar to those found in whole fruits. The present review weighs up the evidence from high-quality studies investigating a potential health harm for FJ against evidence from studies which indicate a potential health benefit. The findings reveal that FJ consumption, at moderate intakes consistent with the dietary guidelines for the US and some European countries (75–224 mL daily), does not increase the risk of obesity, type 2 diabetes, cardiovascular disease or poor glycaemic control. In contrast, regular consumption of FJ—even up to 500 mL per day in short-to-medium-term studies—appears to confer a health benefit in terms of vascular function and reduced blood pressure. Emerging evidence for cognitive health benefits requires further investigation in human trials. Observational studies report associations between FJ and nutrient adequacy and suggest that FJ consumption is associated with reduced risk of stroke. In conclusion, FJ appears to offer more benefit than risk and there appears to be no justification for discouraging FJ within a balanced diet for children and adults.

The potential beneficial effects of plant-based diets on human health have been extensively studied. However, the evidence regarding the health effects of extracted plant-based proteins as functional ingredients, other than soya, is scarce. The aim of this review was to compile evidence on the effects of extracted protein from a wide range of traditional and novel plant sources on glycemic responses, appetite, body weight, metabolic, cardiovascular and muscle health. A comprehensive search of PubMed, EMBASE and The Cochrane Central Register of Controlled Trials (CENTRAL) was conducted through 23 and 27 March 2020 for randomized controlled trials that featured any of the following 18 plant protein sources: alfalfa, duckweed, buckwheat, chickpea, fava bean, hemp, lentil, lupin, mushroom, oat, pea, potato, pumpkin, quinoa, rapeseed, rice, sacha inchi, sunflower. Only interventions that investigated concentrated, isolated or hydrolysed forms of dietary protein were included. Searched health outcome measures were: change in blood glucose, insulin, satiety hormones concentration, subjective assessment of appetite/satiety, change in blood lipids concentration, blood pressure, body weight and muscle health parameters. Acute and sub-chronic studies were considered for inclusion. Applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach we identified 1190 records. Twenty-six studies met the inclusion criteria. Plant protein sources used in interventions were most often pea (n = 16), followed by lupin (n = 4), fava bean (n = 2), rice (n = 2), oat (n = 2), hemp (n = 2) and lentil (n = 1). Satiety and postprandial glycemic response were the most frequently reported health outcomes (n = 18), followed by blood lipids (n = 6), muscle health (n = 5), body weight (n = 5) and blood pressure (n = 4). No studies on the remaining plant proteins in the extracted form were identified through the search. Most studies confirmed the health-promoting effect of identified extracted plant protein sources across glycemic, appetite, cardiovascular and muscular outcomes when compared to baseline or non-protein control. However, the current evidence is still not sufficient to formulate explicit dietary recommendations. In general, the effects of plant protein were comparable (but not superior) to protein originating from animals. This is still a promising finding, suggesting that the desired health effects can be achieved with more sustainable, plant alternatives. More methodologically homogenous research is needed to formulate and validate evidence-based health claims for plant protein ingredients. The relevance of these findings are discussed for the food sector with supporting market trends.