Hardly any other food has experienced as many ups and downs as hen's eggs. Sometimes eggs are seen as a guarantee of an early death, other times they are highly praised as a nutrient-rich, natural food. But what is really behind these contradictory statements?

Nutrients contained in eggs

Eggs are rich in high-quality proteins, vitamins, minerals, good fats and various trace elements. According to the German Federal Center for Nutrition (BZfE), an egg of weight class L contains: 8 g fat and 9 g protein with all (!) 9 essential amino acids but only traces of carbohydrates.

"The protein is of such high quality that it is used as a reference value for the biological value. This means that the human body can utilize 100 percent of this protein. For comparison: the protein in wheat has a biological value of "only" 59, while amaranth has a biological value of 73 and yogurt 83."

Federal Center for Nutrition

Eggs contain:

• iron
• phosphorus
• selenium
• the fat-soluble vitamins A, D, E and K
• the water-soluble B vitamins

Vitamin A - and its precursor, pro-vitamin A (carotene) - is the most important vitamin in eggs. One egg contains approx. 113 mg choline, a very important nutrient for the brain. The best and most nutritious eggs are free-range eggs that are enriched with omega-3 fats. This is done naturally by feeding the hens omega-3-rich seeds.

It is important to know that eggs can be contaminated with salmonella. Salmonella causes gastrointestinal complaints such as diarrhea. Therefore, please ensure that only fresh eggs are used.

Effects of eggs

Eye diseases and eye protection

Eggs are particularly rich in the two antioxidants lutein and zeaxanthin. These belong to the carotenes already mentioned and are what give egg yolks their bright yellow color. These antioxidants accumulate in the retina of the eye, where they protect against harmful sunlight and reduce the risk of eye diseases such as macular degeneration and cataracts. [ 1], [2] In one study, supplementation with an average of 1.3 egg yolks per day for 4.5 weeks increased blood levels of lutein by 28 to 50% and zeaxanthin by 114 to 142%.[3]

Do eggs help you lose weight?

You've probably heard of the "egg diet", which has been circulating in women's magazines since the 1980s. Various versions of a diet that - depending on the version - consists almost exclusively of eggs promise spectacular weight loss. Is there any truth in this?

First of all, eggs are very filling due to their high protein content and last longer than a carbohydrate-rich meal, for example. This makes you less inclined to eat again soon. The fact that eggs contain hardly any carbohydrates also means that they keep you full for longer. do not increase blood sugar levels and therefore do not cause a blood sugar crash. Low blood sugar levels trigger hunger pangs and cravings for sweets.

In a study of 30 overweight or obese women who ate either a bagel or eggs for breakfast, the "egg group" consumed fewer calories than the "bagel group" at lunch, throughout the rest of the day and for the following 36 hours. [ 4]

In another study, overweight adults were each given a breakfast of approximately 340 calories, consisting of eggs for one group and bagels for the other. [ 5]

Result of the "egg group" after eight weeks:

• • 61% greater reduction in BMI
  • 65% more weight loss
  • 34% greater reduction in waist circumference
  • 16% greater reduction in body fat

These results suggest that eggs can indeed contribute to weight loss. However, this is by no means a reason to try the "egg diet". Mono-diets are generally not recommended. We - and our gut bacteria - need variety!

Are eggs good for the brain?

New research shows that eggs are actually beneficial for brain health. In children, eating eggs improves biomarkers of brain development. [6] Among adults, people who eat a lot of eggs perform better on cognitive tests. [ 7] Eggs support optimal cognitive function by supplying the brain with choline and DHA, two crucial brain-supporting nutrients. The aforementioned carotenoid lutein, has been shown to play a crucial role in neurological development. [8]

Do eggs raise cholesterol levels?

For a long time, eggs were considered unhealthy and the recommended amount was limited to two eggs per week because they contain cholesterol. In fact, a large egg contains 212 mg of cholesterol, which is a lot compared to most other foods.

However, many studies have shown that the cholesterol in eggs has no negative effect on blood cholesterol levels. [ 9] In fact, eggs increase "good" HDL cholesterol and improve the particle size of "bad" LDL cholesterol from small and dense to large and fluffy, as is desirable. [10]

A literature review of 17 studies on egg consumption and health found no association between eggs and cardiovascular disease or stroke in otherwise healthy people. [ 11] Other studies also came to the same conclusion. The American Heart Association (AHA) has removed the advice to minimize egg consumption from its recommendations. [12] However, the rumor that eggs have an unfavorable effect on cholesterol levels persists.

Do eggs contribute to cardiovascular disease?

The reputation of eggs has been suffering for decades. Countless studies have demonstrated the link between egg consumption and cardiovascular disease. risk of heart disease. Rong et al [18] found no link, and numerous other studies came to the same conclusion. [19], [20]

However, people with diabetes who eat eggs have been found to have an increased risk of cardiovascular disease.[21] Whether eggs are actually to blame for the increased risk is not known, as these types of studies can only show a statistical correlation. They cannot prove that eggs caused anything.

It is possible that people who eat a lot of eggs and have diabetes are on average less health conscious. On a low-carbohydrate diet, which is by far the best diet for people with diabetes, eating eggs leads to an improvement in heart disease risk factors. [22], [23]

How many eggs can I eat?

Following a wide range of opinions on the consumption of eggs, nutritionists have agreed that eggs should be an important part of a complete diet. As with all other foods, eggs should not be eaten in bulk. For healthy people who do not suffer from diabetes, high blood lipid levels or heart disease, the guideline for egg consumption is three to four eggs per week.

Quality check for eggs

So it looks like you can enjoy eggs without any worries after all. Just please note the codes/print numbers when buying eggs:

• The numbers 0-3: 0 stands for organic, 1 stands for free-range, 2 for barn eggs
• Country abbreviation: CH stands for Switzerland, DE for Germany, AT for Austria
• The barn number stands for the farm.

Freshness test and how do I keep my eggs fresh?

Freshly laid eggs will keep for around a month if stored at a cool room temperature or preferably in the fridge. Boiled eggs, on the other hand, only last two weeks.

If you want to check whether the eggs are still fresh, you can carry out a very simple freshness test. Place the egg in a container of water. Fresh eggs remain at the bottom. Because older eggs have already collected some air inside them, they stand upright in the water. Expired, inedible eggs float on the surface.

You can also tell the approximate age of hard-boiled eggs. Fresh eggs are difficult to peel and older eggs have their yolk closer to the edge with an air chamber.

Our blog is for information purposes only and does not replace a visit to the doctor. We do not recommend any action. You are responsible for your own health. If you have any doubts, consult your doctor before making any changes to your diet or lifestyle.


[1] Delcourt C, Carrière I, Delage M, et al (2006): Plasma lutein and zeaxanthin and other carotenoids as modifiable risk factors for age-related maculopathy and cataract: the POLA Study. Invest Ophthalmol Vis Sci. 2006 Jun;47(6):2329-35.
[2] Karppi J, Laukkanen JA, Kurl S (2012): Plasma lutein and zeaxanthin and the risk of age-related nuclear cataract among the elderly Finnish population. Br J Nutr. 2012 Jul 14;108(1):148-54.
[3] Handelman GJ, Nightingale ZD, Lichtenstein AH, et al (1999): Lutein and zeaxanthin concentrations in plasma after dietary supplementation with egg yolk. Am J Clin Nutr. 1999 Aug;70(2):247-51.
[4] Vander Wal JS, Marth JM, Khosla P, Jen KL, Dhurandhar NV (2005): Short-term effect of eggs on satiety in overweight and obese subjects. J Am Coll Nutr. 2005 Dec;24(6):510-5.
[5] Vander Wal JS, Gupta A, Khosla P, Dhurandhar NV (2008): Egg breakfast enhances weight loss. Int J Obes (Lond). 2008 Oct;32(10):1545-51.
[6] Iannotti LL, Lutter CK, Waters WF, et al (2017): Eggs early in complementary feeding increase choline pathway biomarkers and DHA: a randomized controlled trial in Ecuador. Am J Clin Nutr. 2017;106(6):1482-1489.
[7] Ylilauri MP, Voutilainen S, Lönnroos E, et al (2017): Association of dietary cholesterol and egg intakes with the risk of incident dementia or Alzheimer disease: the Kuopio Ischaemic Heart Disease Risk Factor Study. Am J Clin Nutr. 2017 Feb;105(2):476-484.
[8] Wallace TC (2018): A Comprehensive Review of Eggs, Choline, and Lutein on Cognition Across the Life-span. J Am Coll Nutr. 2018 May-Jun;37(4):269-285.
[9] Kim JE, Campbell WW (2018): Dietary Cholesterol Contained in Whole Eggs Is Not Well Absorbed and Does Not Acutely Affect Plasma Total Cholesterol Concentration in Men and Women: Results from 2 Randomized Controlled Crossover Studies. Nutrients, Sep 2018: 9;10(9).
[10] Blesso CN, Fernandez ML. Dietary Cholesterol, Serum Lipids, and Heart Disease: Are Eggs Working for or Against You? Nutrients. 2018;10(4):426.
[11] 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. BMJ. 2013 Jan 7;346:e8539.
[12] Clayton ZS, Fusco E2, Kern M3 (2017): Egg consumption and heart health: A review. Nutrition. 2017 May;37:79-85.
[13] Tang WH, Wang Z, Levison BS, et al (2013): Intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk. N Engl J Med. 2013 Apr 25;368(17):1575-84.
[14] Velasquez MT, Ramezani A, Manal A, Raj DS (2018): Trimethylamine N-Oxide: The Good, the Bad and the Unknown. Toxins (Basel). 2016 Nov 8;8(11).
[15] Zhang J, Sasaki S, Amano K, Kesteloot H (1999): Fish consumption and mortality from all causes, ischemic heart disease, and stroke: an ecological study. Prev Med. 1999 May;28(5):520-9.
[16] Burr ML, Fehily AM, Gilbert JF, et al (1989): Effects of changes in fat, fish, and fiber intakes on death and myocardial reinfarction: diet and reinfarction trial (DART). Lancet. 1989 Sep 30;2(8666):757-61.
[17] Rong et al, 2016
[18] Rong et al, 2016
[19] Lee A, B Griffin (2006): Dietary cholesterol, eggs and coronary heart disease risk in perspective. Nutrition Bulletin. March 2006, 31:1:21-27.
[20] McNamara DJ (2000): Dietary cholesterol and atherosclerosis. Biochim Biophys Acta. 2000 Dec 15;1529(1-3):310-20.
[21] 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. 1999 Apr 21;281(15):1387-94.
[22] Pearce KL, Clifton PM, Noakes M (2011): Egg consumption as part of an energy-restricted high-protein diet improves blood lipid and blood glucose profiles in individuals with type 2 diabetes. Br J Nutr. 2011 Feb;105(4):584-92.
[23] Blesso CN, Andersen CJ, Barona J, et al (2013): Effects of carbohydrate restriction and dietary cholesterol provided by eggs on clinical risk factors in metabolic syndrome. J Clin Lipidol. 2013 Sep-Oct;7(5):463-71.