Eggs and Health


With Easter, you automatically think bunnies and eggs. But more like chocolate eggs, right? In some cultures, eggs are still the real deal and a treat during the Easter holidays. So why are eggs so tightly connected with spring celebrations? Eggs are the symbol of life, especially in the spring, when you can spot all the animal offspring running around green fields.


When it comes to nutrition, eggs are a good combination of two macronutrients needed for life – protein & fat. The combination of these two (and other micronutrients present) essentially gives life to a chicken, which suggests that eggs are a highly nutritious food item thanks to the balance of present nutrients (Anton et al., 2015). After breast milk, eggs are claimed to be the best source of protein in terms of its quality. Furthermore, eggs are one of the foods containing vitamin D of which our body supplies can be depleted for those living in the UK due to the lack of sunlight, especially after winter. Furthermore, eggs contain a large variety of vitamins and minerals including vitamins A and E and Zinc, which tend to be abundant in Westernised diets (Chen et al., 2018).


Why not separate yolks from whites


Unless it says in the recipe for cooking or textural purposes, separating eggs doesn't make much sense. I came across many people who swear by binning egg yolks due to their fear of putting on weight or consuming cholesterol-rich part of the egg as a result of crazy diet culture or wanting “just the protein part” as a part of their fitness dream. An average-sized boiled egg of 50g contains 78 kcal (Chen et al., 2018), which is hardly anything to fear if consumed in a balanced diet. Meanwhile, egg whites are a good source of protein, the yolks affect the hormonal function of the satiety hormones (Fernandez et al., 2010), which means that eating a whole egg is more likely to keep you feeling

full and prevent you from unwanted snacking as you’re still hungry. And if it's the cholesterol content in egg yolks you're worried about, know that the antioxidant activity in egg proteins act as a prevention of cardiovascular disease (Kostner et al., 2007). If you're suffering from conditions related to high cholesterol, eating eggs as a part of a balanced diet should not be a problem if you're not overdoing it.


What eggs to choose


The amount and quality of nutrients present in eggs are affected by many factors such as the strain, but importantly the hen’s diet and living conditions (Chen at al., 2018). The current market enables us to choose from different types of eggs but also from various conditions that the eggs have been laid in. From the cheapest eggs coming from caged hens to free-range eggs and even to organic eggs or speciality eggs produced by rare hen species, you might wonder what the actual difference is.


The free-range legislative in the EU states that one hen has to be able to run around during the daytime in at least 4m2 (2500 hens per 1 hectare) and share a square meter inside in a group of 9 (Egg Info, 2020). So besides the ethical question, what is the nutritional difference between eggs from caged hens and free-range eggs?


Free-range eggs seem to have much higher bioactivity and even triple the number of carotenoids (Czarnecki et al., 2019) such as β-carotene, which is the substance that gives the egg yolk deeper colour. The higher presence of β-carotene suggests also increased amount of nutrients such as lutein and lycopene. Free-range eggs also seem to be higher in total fat and omega-3 fatty acids, but not cholesterol. This is most likely to be due to the hen's access to richer fat sources in their diet as a result of free-range (Anderson, 2011).


There are also different seasonal eggs that you can spot such as duck, goose or quail eggs. From the smallest of quail eggs to the largest ones, eggs from different poultry animals differ in the amount of energy, mainly due to their size differences but also due to their yolk to white ratios. Duck and goose eggs are associated with higher protein digestibility (Li et al., 2017), as well as a higher nutrient profile, especially in vitamin B12 and then vitamin E and B5. Quail eggs compared to the chicken eggs tend to be higher in some B vitamins, especially in vitamin B2 and slightly in vitamin E (Guyot et al., 2019) however, due to their size and availability, they tend to be consumed purely as a part of gastronomic experience.


So if you fancy spicing up your Easter breakfast and experiment with trying a different egg to your usual chicken or creme eggs, spring is the time to do it.






Sources


Anderson, K., 2011. Comparison of fatty acid, cholesterol, and vitamin A and E composition in eggs from hens housed in conventional cage and range production facilities. Poultry Science, 90(7), pp.1600-8.


Anton, X., Cepeda, A., Franco, C., Lamas, A., Miranda, J., Redondo-Valbuena, C., Roca-Saavedra, P. and Rodriguez, J., 2015. Egg and Egg-Derived Foods: Effects on Human Health and Use as Functional Foods. Nutrients, 7(1), pp.706-29.


Chen, G., Kuang, H., Wang, T., Yang, F. and Zhang, Y., 2018. The Impact of Egg Nutrient Composition and Its Consumption on Cholesterol Homeostasis. Cholesterol, 2018, pp.1-22.


Czarnecki, A., Dróżdź, T., Gałązka-Czarnecka, I., Kiełbasa, P., Korzeniewska, E. and Sójka, M., 2019. Evaluation of Quality of Eggs from Hens Kept in Caged and Free-Range Systems Using Traditional Methods and Ultra-Weak Luminescence. Applied Sciences, 9(12), p.2430.


Egg Info, 2020. Free Range Egg Production - Free Range Eggs | Official Egg Info. [online] Egginfo.co.uk. Available at: <https://www.egginfo.co.uk/egg-facts-and-figures/production/free-range-egg> [Accessed 11 April 2020].


Fernandez, M., Leite, J., de Ogburn, R., Puglisi, M., Ratliff, J. and VanHeest, J. (2010). Consuming eggs for breakfast influences plasma glucose and ghrelin, while reducing energy intake during the next 24 hours in adult men. Nutrition Research, 30(2), pp.96-103.


Guyot, N., Nys, Y. and Réhault-Godbert, S., 2019. The Golden Egg: Nutritional Value, Bioactivities, and Emerging Benefits for Human Health. Nutrients, 11(3), p.684.


Kostner, K., Lim, D., Markovic, T., Natoli, S. and Noakes, M., 2007. Unscrambling the research: Eggs, serum cholesterol, and coronary heart disease. Nutrition & Dietetics, 64(2), pp.105-11.


Li, W., Liu, J., Sun, C., Xu, G. and Yang, N., 2017. Back Cover: Divergent Proteome Patterns of Egg Albumen from Domestic Chicken, Duck, Goose, Turkey, Quail and Pigeon. PROTEOMICS, 17(17-18), p.1770137.