The exuberant search for alternative protein sources (alt proteins) deserves to be supplemented with the rediscovery and enhancement of the consumption of certain foods of animal origin such as eggs, which for all intents and purposes can be qualified as superfood and meet the global needs of food security, without neglecting those related to the sustainable development of agribusiness supply chains. Insight.
1) Eggs, food security and nutrition security
FAO (Food and Agriculture Organization) has just released a report – ‘Contribution of terrestrial animal source food to healthy diets for improved nutrition and health’ – where the indispensable role of animal source protein in achieving the Sustainable Development Goals in UN Agenda 2030 (SDGs, #sdgs2030) related to:
- food security, understood as the security of food supplies for the people of the planet, no one excluded (#SDG2, Zero Hunger), and
- nutrition security as a premise of health and well-being of all human beings (#SDG3, Ensure Health and Well-being), without neglecting the need to ensure
- ‘responsible production and consumption’ (#SDG12), already the subject of special corollary for the food sector in SDG 2 (‘achieve food security and improved nutrition, and promote sustainable agriculture’). (1)
The importance of the socio-economic and cultural functions associated with egg and poultry production-for the livelihood of smallholder farmers and their communities (#SDG1, End Poverty)-has itself been widely recognized in previous FAO reports (2,3,4).
2) Eggs, a superfood to be rediscovered
Eggs are a source of noble proteins with high biological value, as they contain all the essential amino acids-necessary for the many plastic, structural, and catalytic functions of our bodies-in a highly digestible form. To which is added a generous supply of micronutrients.
‘Egg is an encapsulated source of macro and micronutrients that meet all requirements to support embryonic development until hatching. The perfect balance and diversity in its nutrients along with its high digestibility and its affordable price has put the egg in the spotlight as a basic food for humans’ (Réhault-Godbert et al., 2019). (5)
2.1) Proteins, amino acids and their digestibility.
The nutritional quality of protein in foods is essentially related to two factors:
- essential amino acids. Proteins are made up of amino acids, used by the human body to build (the proteins of) its tissues. 9 out of 20 amino acids are defined asessential (indispensable AA), since the body cannot synthesize them and therefore must receive them from outside, through food. Eggs qualify as a superfood, first and foremost, because of a ‘protein package’ that includes all the essential amino acids,
- Bioavailability of amino acids. The quality of protein from different food sources is also evaluated according to the digestibility of amino acids, and thus their effective usability by the body. And the most recent studies, conducted by various methods, place eggs at the highest levels (89.5 ± 4%, next to meat, 92 ± 3%) in the essential amino acid absorption index. (6)
2.2) Vitamins
Egg yolk contains high amounts of vitamins A, D, E, K, B1, B2, B5, B6, B9 and B12, while egg white has high amounts of vitamins B2, B3 and B5, as well as appreciable contents of vitamins B1, B6, B8, B9 and B12. (5) The content of fat-soluble vitamins (A, D, E, K), as well as the prevalence of unsaturated fatty acids (e.g., linoleic acid), in egg yolks varies significantly depending on the hen’s diet (Réhault-Godbert et al., 2019). (5)
2.3) Vitamin D, focus
The vitamin D in which eggs are rich (2 µg/100g, or 40 percent of the nutritional reference value) offer an additional cue to qualify this food as a superfood. Of particular importance, for nutrition security, given that:
- 50% of the population has vitamin D insufficiency (7,8),
- Vitamin D deficiency is prevalent in elderly and obese patients (+35%), (9)
- Vitamin D, as noted, plays an essential role in stimulating the immune system. (10)
2.4) Minerals, choline and mental and physical health.
The rich endowment of eggs in minerals confirms their role as a superfood. The richness in phosphorus, calcium and potassium is complemented by the presence of all essential trace elements including copper, iron, magnesium, manganese, selenium and zinc.
The presence of these minerals and micronutrients in the egg is of interest for psychophysical health, as deficiency of some of them (Zn, Mg, Se) has been associated with depression and fatigue and the development of pathological diseases (Wang et al., 2018). (11)
Choline-of which egg is the second largest dietary source (680 mg/100 g in the yolk), after beef liver-has an important role in cell growth at all stages of life. With emphasis on neurotransmission and brain development, as well as bone integrity. (12)
3) Eggs and nutraceuticals
Some characteristics of eggs, related to nutraceutical and superfood haloes, are already known and unfortunately so far little explored in the manner required for the purpose of authorizing appropriate health claims. Some insights in this regard:
- Antioxidant action. Chicken egg contains many antioxidant compounds. Vitamins, carotenoids, minerals and trace elements, but also the major proteins of egg white (ovotransferrin) and egg yolk, including phosphvitin,
- immuno-modulation. lysozyme from egg white is a promising agent for reducing intestinal oxidative stress, as shown in a study on swine colitis (Lee et al., 2009), (13)
- Antihypertensive activity. Some egg yolk peptides, described in the literature for their ability to protect the cardiovascular system, have demonstrated such virtues in in vivo animal studies, (14)
4) Fats and cholesterol, the myths to dispel.
The composition of a whole, raw, freshly laid egg is water (76.1%) protein (12.6%), fat (9.5%), carbohydrates (0.7%) and ash 1.1%). (15) Therefore, eggs are also ideal superfoods for the ketogenic diet, or keto diet, and beyond.
The content of unsaturated fatty acids (MUFA and PUFA, Mono-Unsaturated Fatty Acids and Poly-Unsaturated Fatty Acids), in eggs, is more than double that of saturated fatty acid profile (5.31 g versus 2.64 g per 100 g of whole egg).
Fatty acid profiles vary substantially with the diet of hens. Functional feeds with microalgae can further improve the nutritional quality of eggs, as well as enable the elimination of antibiotics (17,18).
4.1) Eggs and cardiovascular health.
Peking University coordinated the largest cohort study (Qin et al., 2018) ever conducted-over half a million individuals-to assess possible correlations between egg consumption and cardiovascular disease, ischemic heart disease, major coronary events, hemorrhagic strokes, and ischemia. (17)
The study not only confirmed the absence of cardiovascular risks associated with quotoday egg consumption (Abdollahi et al., 2018. See footnote 18), but rather showed that this results in a substantial reduction in the risk of death from stroke (-28%) and cardiovascular disease in general (-18%).
The Peking University Health Science Center therefore significantly associated regular and (relatively) moderate consumption of eggs, (up to 1 egg/day) with a lower risk of Cardiovascular Diseases (CVDs), largely independent of other risk factors. (17)
5) Research perspectives
‘Besides basic nutrients, eggs are also a great source of potential nutraceuticals. A total of 550 distinct proteins were identified so far in egg-white and yolk/vitelline membranes and the physiological function of only 20 of them is characterized to date.
This remark suggests that the egg probably still encloses many unknown activities that merit further investigations considering the current lack of research assessing the fate of egg proteins along the digestive tract. Besides basic nutrients, eggs are also a great source of potential nutraceuticals‘ (Réhault-Godbert et al., 2019).
6) Interim conclusions. What eggs?
The choice of eggs should favor organic production because of the better animal welfare and biodiversity conditions associated with the hens’ nutrition (no GMO raw materials or use of pesticides, as well as no chemical additives).
Eggs from hens raised without antibioticsshould be favored above all, thanks to the use of mixes of microalgae, algae and florotannins that are compatible with the standards of organic production already successfully tested precisely in Italy (18,21).
The optimal consumption of eggs-to better tap into the nutritional and nutraceutical benefits associated with this superfood-is ‘poached’ or ‘soft-boiled.’ Namely, cooking the egg white (to inactivate anti-nutritional factors and potential pathogenic bacteria) and almost raw yolk (to preserve most vitamins, lipids, micronutrients and some bioactive molecules (antioxidants).
Dario Dongo
Notes
(1) Marta Strinati, Dario Dongo. Food of animal origin needed for nutrition and health, FAO report. GIFT (Great Italian Food Trade). 8.5.23
(2) Dario Dongo, Alessandra Mei. Poultry and eggs, global demand on the rise. The challenge of sustainability. GIFT (Great Italian Food Trade). 3.2.20
(3) FAO (2018). Eggs: harnessing their power for the fight against hunger and malnutrition. https://bit.ly/3pP8OhX Global Forum on Food Security and Nutrition.
(4) FAO (2013). Poultry Development Review. https://bit.ly/3WbAlWJ ISBN 978-92-5-108067-2 (PDF).
(5) Réhault-Godbert S, Guyot N, Nys Y. The Golden Egg: Nutritional Value, Bioactivities, and Emerging Benefits for Human Health. Nutrients. 2019 Mar 22;11(3):684. doi: 10.3390/nu11030684
(6) Gaudichon C, Calvez J. Determinants of amino acid bioavailability from ingested protein in relation to gut health. Curr Opin Clin Nutr Metab Care. 2021 Jan;24(1):55-61. doi: 10.1097/MCO.0000000000000708
(7) Nair R, Maseeh A. Vitamin D: The “sunshine” vitamin. J Pharmacol Pharmacother. 2012 Apr;3(2):118-26. doi: 10.4103/0976-500X.95506
(8) Sizar O, Khare S, Goyal A, et al. Vitamin D Deficiency. (2023). In: StatPearls Publishing. https://bit.ly/3Mc39tM Treasure Island (FL, USA).
(9) Pereira-Santos M, Costa PR, Assis AM, Santos CA, Santos DB. Obesity and vitamin D deficiency: a systematic review and meta-analysis. Obes Rev. 2015 Apr;16(4):341-9. doi: 10.1111/obr.12239
(10) Dario Dongo, Andrea Adelmo Della Penna. Vitamin D, immune system, and Covid-19. New scientific evidence. GIFT (Great Italian Food Trade). 29.9.20
(11) Wang J., Um P., Dickerman B.A., Liu J. Zinc, Magnesium, Selenium and Depression: A Review of the Evidence, Potential Mechanisms and Implications. https://bit.ly/3BDPEye Nutrients. 2018;10:584. doi: 10.3390/nu10050584
(12) 54. Wiedeman A. M., Barr S. I., Green T. J., Xu Z., Innis S. M., Kitts D. D. Dietary Choline Intake: Current State of Knowledge Across the Life Cycle. Nutrients. 2018;10:1513. doi: 10.3390/nu10101513
(13) Lee M., Kovacs-Nolan J., Yang C., Archbold T., Fan M.Z., Mine Y. Hen egg lysozyme attenuates inflammation and modulates local gene expression in a porcine model of dextran sodium sulfate (DSS)-induced colitis. J. Agric. Food Chem. 2009;57:2233-2240. doi: 10.1021/jf803133b
(14) Chen S., Jiang H.M., Peng H.H., Wu X.S., Fang J. The Utility of Ovotransferrin and Ovotransferrin-Derived Peptides as Possible Candidates in the Clinical Treatment of Cardiovascular Diseases. Oxid. Med. Cell. Longev. 2017 doi: 10.1155/2017/6504518
(15) USDA National Nutrient Database for Standard Reference, Release 1. U.S. Department of Agriculture. Food Group: Dairy and Egg Products; Beltsville, MD, USA: 2018
(16) Adele Fantoni. Keto diet and very low carb diet, the ABCs. GIFT (Great Italian Food Trade). 12.8.22
(17) Park J.H., Upadhaya S.D., Kim I.H. Effect of dietary marine microalgae (schizochytrium) powder on egg production, blood lipid profiles, egg quality, and Fatty Acid composition of egg yolk in layers. https://bit.ly/3IlrrQS Asian-Australas. J. Anim. Sci. 2015;28:391-397. doi: 10.5713/ajas.14.0463
(18) Dario Dongo, Andrea Adelmo Della Penna. Antibiotic-free poultry farming, the Italian way. GIFT(Great Italian Food Trade). 14.12.20
(19) Qin C, Lv J, Guo Y, Bian Z, Si J, Yang L, Chen Y, Zhou Y, Zhang H, Liu J, Chen J, Chen Z, Yu C, Li L; China Kadoorie Biobank Collaborative Group. Associations of egg consumption with cardiovascular disease in a cohort study of 0.5 million Chinese adults. https://bit.ly/2CL6AXd Heart. 2018 Nov;104(21):1756-1763. doi: 10.1136/heartjnl-2017-312651
(20) Marta Strinati, Dario Dongo. An egg a day, green light from research in Finland. GIFT (Great Italian Food Trade). 5.6.19
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
