Nutrition Myth #5 - Eggs cause high cholesterol

Eggs have had a bad press for a long time, often related to cholesterol.  There has long been the belief that dietary cholesterol is directly attributable to blood cholesterol but 30 years of research has dismissed this idea.  Dietary cholesterol in foods such as eggs has only a small and clinically insignificant effect on blood cholesterol, especially when compared with the much greater effects of dietary saturated fatty acids on blood cholesterol. (1-8)

In fact there is plenty of evidence that eggs are incredibly good for you.

In a controlled trial eating eggs for breakfast versus bagels of the same caloric value, improved weight loss as part of a calorie controlled diet (9)  - there was no difference in weight loss or gain in an unrestricted diet (9, 10).   So eggs don’t make you lose weight but calories for calories, they help us lose weight by swapping out our white carbs for eggs.

Eggs have one of the lowest energy to nutrient density ratios of any food, and contain a quality of protein that is superior to beef steak and similar to dairy.

Eggs contain all essential amino acids for humans (11). They also contain several vitamins including choline, retinol, riboflavin, folic acid, vitamin B6, vitamin B12, iron, calcium, phosphorus, potassium, CQ10 (12).  Vitamins A, D and E are concentrated in the yolk, making it one of the few foods to naturally provide vitamin D.  The yolk contains all of the fat, slightly less than half of the protein and most of the nutrients.  It also contains all of the choline – one egg provides half the recommended daily intake.

Choline plays an important role in the metabolism of fat; it breaks fat down for use as an energy source.  This action of choline makes it valuable in preventing conditions like fatty liver or excess fat in the blood.  Choline’s efficient metabolism of fats has also been linked to a greater level of satiety, which, in turn, leads to a decreased consumption of calories, resulting in overall weight loss.  A 2014 study of athletes reported Choline supplements improved fat loss of 10.23% as a percentage of body fat compared to 4.05% without. (13, 14)

And the lipid matrix within the egg yolk increases bioavailability of nutrients, including lutein and zeaxanthin (15).

In essence….eggs are awesome.

Boil up a batch of hard-boiled eggs on a Sunday evening for the next 5 days and they are your breakfasts and snacks throughout the week, even unrefrigerated, they will be just fine.

Top Tip:   Why are some hardboiled eggs super easy to peel and others a complete biatch?  The fresher the eggs, the harder they are to peel.   The albumen (white) of a just-laid egg contains a store of dissolved carbon dioxide, a weak acid. Over time, the gas exits the egg through the pores in the shell.  As this happens, the pH of the white gradually increases, making it less acidic.  The inner membrane of an egg—that translucent skin that envelopes the albumen—is made partly from a protein called keratin (also found in hair and nails), which is tougher in an acidic environment.  At the lower pH of a fresh egg, the proteins in the egg white bind tightly to the keratin in the membrane during the cooking process, which makes it nearly impossible to remove the shell without chunks of white attached. Up the alkalinity, and the keratin softens, leading to a looser bond between the white and the membrane - which means hassle-free peeling.

For easy peeling, either buy less fresh eggs or keep them for a few days before boiling them.

References: 

  1. Gray J. and Griffin B. (2009). “Eggs and dietary cholesterol – dispelling the myth.” Nutrition Bulletin. 34: 66-70.

  2. Qureshi AI, Suri FK, Ahmed S et al. (2007). “Regular egg consumption does not increase the risk of stroke and cardiovascular diseases.” Medical Science Monitor. 13, CR1–CR8.

  3. Barraj L, Tran N, Mink P. (2009). “A comparison of egg consumption with other modifiable coronary heart disease lifestyle risk factors: a relative risk apportionment study.” Risk Analysis. 29, 401–415.

  4. Scrafford CG, Tran NL, Barraj LM et al. (2011). “Egg consumption and CHD and stroke mortality: a prospective study of US adults.” Public Health Nutrition. 14, 261–270.

  5. Hu FB, Stampfer MJ, Rimm EB et al. (1999). “A prospective study of egg consumption and risk of cardiovascular disease in men and women.” JAMA 281, 1387–1394.

  6. Kritchevsky SB & Kritchevsky D. (2000). “Egg consumption and coronary heart disease: an epidemiologic overview”. Journal of the American Colledge of Nutrition. 19, S549–S555.

  7. Shin JY, Xun P, Nakamura Y. et al. (2013). “Egg consumption in relation to risk of cardiovascular disease and diabetes: a systematic review and meta-analysis.” American Journal of Clinical Nutrition. 98, 146–159.

  8. Rong Y, Chen L, Zhu T et al. (2013). “Egg consumption and risk of coronary heart disease and stroke: dose response meta-analysis of prospective cohort studies.” British Medical Journal. 346, e8539.

  9. Wal J, Gupta A, Khosla P. et al. (2008). “Egg breakfast enhances weight loss”. International Journal of Obesity. 32, 1545–1551 (2008).

  10. Keogh JB, Clifton PM. (2020). "No Difference in Weight Loss, Glucose, Lipids and Vitamin D of Eggs for Breakfast Compared with Cereal for Breakfast during Energy Restriction". International Journal of Environmental Research and Public Health. 17, no. 23: 8827

  11. Food and Agriculture Organization (2004).  Poultry Development Review.  Rome, Itally.

  12. United States Department of Agriculture (2005)  “Vitamin A RAE content of selected foods per common measure, sorted by nutrient content”  USDA.  Beltsville.  MD.  USA.  P4

  13. Heron KL, Fernandez LM  (2004).  “Are the current dietary guidelines regarding egg consumption appropriate?”.  Journal of Nutrition.  134(1):  187-190

  14. Hanin I, Ansell GB. (1987). “Lecithin”. Technological, Biological, and Therapeutic Aspects. Plenum Press; NY. pp. 180–181.

  15. Elsawy G, Abdelrahman O, Hamza A. (2014) “Effect of choline supplementation on rapid weight loss and biochemical variables among female taekwondo and judo athletes”. Journal of Human Kinetics. Apr 9;40:77-82.