I love eggs……..The King of Protein?
What came first, the chicken or the egg? How good is it as a protein source?
Probably not one of nutrition’s hot topics at present but in this article I’d like to discuss the potential health promoting properties of the humble hen’s egg.
First and foremost protein quality:
When the goal is either hypertrophy or fat loss, how much protein we should be consuming and its quality is very important. Protein helps us stay fuller for longer (1). It even helps us grow and preserve our hard earned muscle (2). For those interested in weight training, the growth or preservation of muscle mass is of upmost importance. One way to determine the quality of a protein is its protein digestibility-corrected amino acid score (PDCAAS). This is recognised by the World Health Organisation (WHO) as the current internationally approved method for protein quality assessment (3). Egg white scores right at the top of the PDCAAS. The leucine content (a key amino acid involved in muscle growth (4)) of 1 large whole egg is around 544mg. You would need to eat around 6 large eggs to meet Leucine requirements (5-6) and help maximally stimulate the muscle growing potential.
In the 1970s the American heart association suggested we should restrict egg consumption and limit our total cholesterol intake to less than 300mg. With one large egg containing around 150mg, consuming any more than 2 would, by this recommendation mean overconsumption. In 2000 these guidelines were reviewed (7). A low egg intake did not increase coronary heart disease risk (8) and in a cohort study representing the US population, Adnan et al 2006 (9) found that consuming between 1-6 eggs per day did not increase the risk of coronary artery disease or stroke. Furthermore, in a review of recommendations regarding eggs Kritchevsky et al (10) concluded; “In summary, eight studies have reported on the egg consumption and coronary heart disease (CHD) risk directly. On the whole, they do not support the contention that egg consumption is a risk for CHD.”
Many people believe that the egg white is the only protein source; however one yolk contains over 7g of protein. With the added benefit of being loaded with vitamins A, D, riboflavin, folate and B-12 the yolk really is the most nutrient dense part of the egg. Including the yolk as part of your overall diet will also help you meet requirements for heart healthy poly and monounsaturated fatty acids. Balance out your fat intake and don’t throw away those yolks.
Raw vs Cooked eggs:
In 1998 Evenepoel et al (11) examined the effects of cooked vs raw eggs and discovered that there was a significant difference in protein utilisation between the two different preparation methods. Non-pasturised raw eggs could result in an increased risk of salmonella poisoning (12) however the British Lion scheme in the UK has meant stricter controls on hens vaccinated against salmonella. These stamped eggs meet the highest food safety standards. Pasturised egg whites have been deemed safe for raw consumption; however in 2013 Myprotein recalled their bottled egg whites after links to salmonella poisoning (13) were identified. With even a hint of potential risk and no further benefit I would always recommend cooking your eggs before consuming them.
To conclude, eggs are an inexpensive high quality protein source rich in vitamins A, D, B-12, B-6 and minerals calcium and magnesium. They should form part of a colorful, well balanced diet, rich in whole grains, fruits, vegetables and lean protein sources.