The food industry is constantly evolving and it’s not always easy to know what is good and what is bad. Simply by observing the latest changes made to the new food guide, we can see that overnight, a food can be considered harmful, when a few months earlier it was considered beneficial for health.
Cholesterol and eggs
Eggs were quickly singled out when it came to cholesterol. These days, one can be confused with all the conflicting information that is circulating. But, do we really have to worry about our egg consumption?
It all started in the 1970s. Health authorities have declared that cholesterol is responsible for heart disease. It was then that the food guide had a new addition supported by the American Heart Association (AHA): an intake limit of 300 mg of cholesterol per day. Intensive research to identify dietary sources of cholesterol has led to significant limitations of certain foods. Eggs were not spared. For our health, we should not consume more than one egg per day and not every day.
If we take a closer look, eggs nevertheless contain several very nutritious sources such as:
- B vitamins (riboflavin, B12, folates),
- Vitamins A, D, K,
- Quality proteins and lipids (omega 3, DHA)
- Antioxidants (lutein and zeaxanthin; useful for the prevention of macular degeneration)
In addition, Health Canada published a report in the year 2000, which concluded that dietary cholesterol did not have a great impact on cholesterol levels in the blood. Committee members relied on science published between 1993 and 1999 to state that there was no significant effect of dietary cholesterol on blood cholesterol levels. So why is there still a debate about egg consumption?
An essential source
Let’s take a moment to talk about a nutrient found in eggs: choline. Essential for the brain, this nutrient had, however, been put forward by the media by reporting the results from a study which mentioned that consuming choline could increase a compound, called TMAO (trimethylamine N-oxide) , possibly dangerous for the cardiovascular system. For some, this was therefore an additional argument to help reduce egg consumption.
However, it is possible to read in a recent study that the level of TMAO does not increase with the consumption of 3 eggs per day for 4 weeks, and that in addition, this would increase the blood circulation of choline and HDL (protectors). Other studies have concluded that eggs are not harmful to our health.
Other studies favoring eggs
1- Two studies were published in 2015 and 2018 by the team of Dr. Nicholas R Fuller at the University of Sydney in Australia. For 12 weeks, these 2 studies observed participants with type 2 diabetes or prediabetes, who ate 2 eggs per day. It was then shown that there was no impact on blood parameters or other measurable negative effects.
2- The conclusion of a Chinese study carried out on half a million adults was that people who ate 1 egg per day show less cardiovascular risk than people who do not.
3- On a smaller scale, a study with 30 participants found that a person who consumes 3 eggs per day does not show any change in their bad/good cholesterol ratio (LDL/HDL). Eggs have even been observed to decrease cholesterol synthesis by the liver.
4- In 2017, a systemic review (compilation of several studies) on the subject was published. In the end, this led to the conclusion that there is no risk in consuming 12 eggs per week.
Eggs therefore contain several good nutrients for health, and would not be as damaging as people try to make us believe. So, don’t stop enjoying it at lunch or in any other dish. If you haven’t already, reserve a spot for them in your kitchen again!
Jean-Yves Dionne, Pharmacist
- DiMarco DM, Missimer A, Murillo AG, Lemos BS, Malysheva OV, Caudill MA, Blesso CN, Fernandez ML. Intake of up to 3 Eggs/Day Increases HDL Cholesterol and Plasma Choline While Plasma Trimethylamine-N-oxide is Unchanged in a Healthy Population. Lipids. 2017 Mar;52(3):255-263. doi: 10.1007/s11745-017-4230-9. PubMed PMID: 28091798. https://www.ncbi.nlm.nih.gov/pubmed/28091798
- Fuller NR, Caterson ID, Sainsbury A, Denyer G, Fong M, Gerofi J, Baqleh K, Williams KH, Lau NS, Markovic TP. The effect of a high-egg diet on cardiovascular risk factors in people with type 2 diabetes: the Diabetes and Egg (DIABEGG) study-a 3-mo randomized controlled trial. Am J Clin Nutr. 2015 Apr;101(4):705-13. doi: 10.3945/ajcn.114.096925. PubMed PMID: 25833969. https://www.ncbi.nlm.nih.gov/pubmed/25833969
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- Lemos BS, Medina-Vera I, Blesso CN, Fernandez ML. Intake of 3 Eggs per Day When Compared to a Choline Bitartrate Supplement, Downregulates Cholesterol Synthesis without Changing the LDL/HDL Ratio. Nutrients. 2018 Feb 24 ;10(2). pii: E258. doi: 10.3390/nu10020258. PubMed PMID: 29495288; PubMed Central PMCID: PMC5852834. http://www.mdpi.com/2072-6643/10/2/258
- 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. Heart. 2018 May 21. pii: heartjnl-2017-312651. doi: 10.1136/heartjnl-2017-312651. [Epub ahead of print] PubMed PMID: 29785957. http://heart.bmj.com/content/early/2018/04/17/heartjnl-2017-312651
- Health Canada Scientific Summary on the U. S. Health Claim Regarding Dietary Fat, Saturated Fat, Cholesterol, Trans Fatty Acids and Coronary Heart Disease : https://www.canada.ca/en/health-canada/services/food-nutrition/food-labelling/health-claims/assessments/scientific-summary-health-claim-regarding-dietary-saturated-cholesterol-trans-fatty-acids-coronary-heart-disease.html
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- Tang WH, Wang Z, Levison BS, Koeth RA, Britt EB, Fu X, Wu Y, Hazen SL. Intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk. N Engl J Med. 2013 Apr 25;368(17):1575-84. doi: 10.1056/NEJMoa1109400. PubMed PMID: 23614584; PubMed Central PMCID: PMC3701945. https://www.nejm.org/doi/full/10.1056/NEJMoa1109400