Eggs: Healthy or Risky? A Review of Evidence from High Quality Studies on Hen’s Eggs

Abstract

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.

The Effect of Choline and Resistance Training on Strength and Lean Mass in Older Adults

“…However, there is no clear association between egg consumption and cardiovascular disease mortality [ 46 ], and some studies found that egg consumption may even improve lipoprotein profiles [ 47 ] or suppress ischemic heart diseases [ 48 ]. According to a recent study, consuming 7–14 eggs/week as part of a balanced diet can be beneficial for most people [ 49 ].…”

Comparison of Fatty Acid Profile in Egg Yolk from Late-Age Hens Housed in Enriched Cages and in a Free Range System

“…The lipid composition of egg yolk is a primary consumer concern especially in relation to cholesterol content, as it was viewed in the past as a negative nutrient. However, recent evidence from randomized controlled trials suggests that eggs tend to have overall small effects on blood cholesterol levels [5]. Previously, Qureshi et al [29] demonstrated that consuming more than six eggs per week or one egg or greater per day did not increase the risk of coronary artery disease.…”

“…However, eggs are also high in cholesterol. Cholesterol was considered in the past to be a negative nutrient, although the risk assessment has evolved in line with more recent evidence suggesting a smaller impact of dietary cholesterol on cardiovascular disease risk than saturated fat [4,5]. The internal and external qualities of eggs can be influenced by various factors, e.g., the hen's genetic type, laying hen age, feeding strategy, and animal welfare; the latter is linked to the production system [3,6].…”

Design of Physicochemical Properties of Eggs as a Result of Modification of the Fat Fraction of Laying Feed

“…Today, there is no doubt that the type and quality of food consumed have a strong impact on human health. As a result, many studies are focused on improving food products, with a significant amount of research devoted to modifying the composition and properties of eggs [ 1 ].…”