Questions About Egg Cholesterol Resolved By Modern Research
To Eat Or Not To Eat?
Moments before beginning to write the current article, I discovered another article on the internet written by a nutrition expert with a PhD, advocating avoidance of eggs to reduce risks of heart disease and stroke. This is a prime example of how modern research on eggs has not completely caught on consistently in all disciplines or in all countries of the world, let alone caught on consistently with non-expert health enthusiasts. Old fears (partly fueled by small uncertainties and inconsistencies between certain studies) still appear to abound in some people. Ingrained behavior, based on, at best, inconclusive evidence of the past, thus, is hard to modify. Habits based on unjustified fear of eggs are reflexive, lodged at the deepest level of our physical structure, where we no longer think with our minds.
I am one of those people who grew up with an attitude of extreme caution about eating eggs. I was a health advocate, fitness instructor, and athlete for dozens of years. Like many, when I thought "egg", I automatically thought "cholesterol", "clogged arteries", "heart attack", and "stroke". In fact, I cannot remember a more formidable warning in the area of nutrition than the warning "to limit consumption of eggs to no more than three per week."
The conflict between old ideas and new ideas seems to keep discussions about eggs controversial. When a PhD in nutrition tells you to avoid or limit consumption of eggs, while a team of researchers tells you that doing so really has little effect on blood cholesterol, then personal decision making can find itself in a ping pong match.
What should people do? Do we eat eggs, free of guilt and fear? Or do we play it safe and practice the same old habits that now conflict with modern findings? These are the sorts of questions that went through my mind, before I got serious about trying to find out the truth.
Revised Philosophy Based On Research
Before looking deeper into the issue, I had read a few general articles professing a new awakening about cholesterol, but I had not felt confident that these sources were reliable. Consequently, I decided to settle the issue once and for all in my own mind, by going to original, expert research. Here is what I found:
Adnan I. Qureshi, M. Fareed K. Suri, Shafi udin Ahmed, Abu Nasar, Afshin A. Divani, Jawad F. Kirmani, (2007). Regular Egg Consumption Does Not Increase the Risk of Stroke and Cardiovascular Diseases. MED SCI MONIT., 13(1): CR1-8, https://www.sapoultry.co.za/pdf-egg-info/mcnamara/Egg-Cholesterol/regular-egg-consumption.pdf [downloaded 05/25/2017].
This study was performed by the Epidemiological and Outcomes Research Division, Zeenat Qureshi Stroke Research Center, Department of Neurology and Neurosciences, University of Medicine and Dentistry of New Jersey, Newark, NJ, U.S.A. It examined the association between egg consumption and risk of cardiovascular diseases and mortality in a national sample of 9734 adults, ages 25 to 74 years. Researchers reported:
- We did not observe an increased risk for stroke, ischemic stroke, or coronary artery disease with weekly consumption of greater than 6 eggs per week or 1 egg or greater per day.
The researchers did mention in their conclusion:
- "The increased risk of coronary artery disease associated with higher egg consumption among diabetics warrants further investigations."
I am not a doctor, and I am not advising anybody here as if I were. Rather, I am showing the sources of my own decision making. When I look for original research on a specific topic and find a conclusion that contradicts what I have been led to believe in popular writings, I have to question my former beliefs and adjust my current habits accordingly. I, therefore, cannot continue my old behavior, based on my new discovery of evidence that invalidates this old behavior.
One of the studies on cholesterol that I read is the following:
Nicola L. Harman, Anthony R. Leeds, Bruce A. Griffin, (2008). Increased Dietary Cholesterol Does Not Increase Plasma Low Density Lipoprotein when Accompanied by an Energy-Restricted Diet and Weight Loss, EUR J NUTR., 47:287-293, http://www.ovosbrasil.com.br/site/wp-content/uploads/2016/09/2008-Harman_Increased-dietary-cholesterol-does-not-increase-plasma-low-density-lipoprotein-when-accompanied-by-an-energy-restricted-diet-and-weight-loss_Surrey.pdf [downloaded 05/25/2017].
Even though, this study was partly supported by the British Egg Industry Council, UK., two of the researchers are medical or nutritional scientists at the university level, namely Bruce A. Griffin is Faculty of Health and Medical Sciences, University of Surrey, UK, and Anthony R. Leeds is Dept. of Nutritional Sciences King’s College London, UK. I trust that the integrity of university medical or nutrition departments was not compromised for political purposes, and that the scientists here got funding where they could, in order to do what scientists do.
In other words, of course the egg industry would benefit from a positive view of eggs, but a person cannot automatically assume that it hires scientists to falsify facts. Again, we are talking about university medical and nutrition establishments. It would be in the egg industry's best interest to fund legitimate studies to undo ideas that were wrong from the get go. Scientists do what they do, and industry does what it does -- a win/win situation, not a conspiracy.
Here is what this study concluded:
- "In conclusion, this study demonstrates that increasing dietary cholesterol by consuming two eggs a day, produces no increase in plasma LDL when accompanied by energy restriction and moderate weight loss. ... These findings support the view that cholesterol-rich foods should not be excluded from an energy-restricted diet on account of producing an unfavorable effect on blood cholesterol."
"LDL", for those who might not know, stands for "Low Density Lipoprotein", which is the substance that carries so called "bad cholesterol", as opposed to HDL ("High Density Lipoprotein", which carries so called "good cholesterol")
Here is my understanding of the study:
It basically divided a group of people into two smaller groups, restricted the calorie intake of both groups, allowed one group to eat two eggs a day, while allowing the other group to eat no eggs. It compared the two groups and found that LDL-cholesterol levels were reduced in both the egg eating group and the non egg eating group.
This seems to be great news for people wanting to restrict their calories in order to help loose weight, because they could include eggs in their diets as an extremely high-quality protein. Also, people who are not overweight or prone to other risks or conditions might eat eggs with a greater sense of freedom and less worry.
A single study does not seem sufficient to justify altering long-held beliefs. A scrutinizing person looks for other studies that replicate or lend support to this one study's findings. In that vein, I looked at this:
The National Heart Foundation of Australia, (2016). EVIDENCE PAPER: EGGS AND THE HEART -- a 26-page report by Australia's leading heart health organization, in which nine different reviews encompassing over two hundred studies arrived at the following conclusion:
- "Whilst the evidence is not clear enough to say that there is no association between dietary cholesterol and heart disease risk, there is also not strong enough evidence to warrant continuing recommendations to limit egg intake to three per week. A prudent recommendation is a limit of six to seven eggs per week for people at increased risk of heart disease. ... The exception is people with type 2 diabetes, for whom eggs may increase risk, and possibly people with heart failure."
Based on my reading of this entire report, I would feel comfortable extending its conclusion even further for myself, by not worrying too much about exceeding seven eggs a week, since conscientious eating habits are already in practice, no body fat issues are present, and very consistent (although moderate and gentle) physical activity is firmly established.
Based on the above literature, in combination with other literature that I did not highlight here, my personal conclusion is that a person's overall eating patterns and physical activity patterns influence how dietary cholesterol affects human health.
Demonizing any one food for any one reason or association is an oversimplification that can lead to needless worry and perhaps to undesirable effects. I, therefore, view eggs as a superior form of protein whose benefits far outweigh any uncertainties. A fit, healthy, physically active person, therefore, seems justified in feeling at ease eating up to seven eggs a week. Eating any more or less than seven a week is a personal judgment that might best be guided with regular cholesterol monitoring through a doctor's care.