Much like the milk and meat controversy, the egg debate has been going on for years. One day, eggs are a major power protein. The next day, they are as bad for you as cigarette smoking. Just last month, national headlines reported, “Egg yolks almost as bad as smoking”, “Eggs Are Nearly as Bad for Your Arteries as Cigarettes”, and finally, “What do egg yolks and cigarettes have in common?” We are once again left confused, and wondering if that three-egg omelet is really a good idea after all?
Recently, a research study by Dr. David Spence, a professor at Western University of Ontario Canada, proclaimed that eating egg yolks regularly (at least 4.5/week) was 2/3 as bad as smoking. Yes, you heard it: eating eggs could kill you almost as fast as puffing away on a pack of Marlboros.
Dr. Spence questioned 1,231 elderly men and women from the London Health Science Center, who were recovering stroke patients, on their egg consumption, smoking habits, medications and other lifestyle habits. Ultrasound was then used to measure the amount of plaque build-up in each of the patients.
The study found that those who ate more egg yolks per week had almost 2/3 the plague build-up of heavy smokers. The study showed that those who smoked the most and ate the most egg yolks had the most plaque build-up. In comparison, those who smoked the least and ate the least amount of yolks had far less plaque build up. The study also concluded that those who smoked the most also ate the most egg yolks. Apparently, in this study, it seems that egg yolk eaters had a few other bad habits other than just eating eggs. Which, in my opinion, should have made Dr. Spence look deeper into other causation factors as to why egg-yolk eaters had increased plaque build-up.
To really judge if eggs are the death trap Dr. Spence makes them out to be, we need to look at a few possible problems with his study…
1. The questionnaire
Dr. Spence used a questionnaire asking, based on the average per week, throughout your entire life, how many eggs have you consumed each year (“egg-yolk-years”)? Now, I don’t know about you, but I can barely remember what I ate last week. So I am not too sure these elderly stroke patients have a clear memory of their dietary habits for the last 50-70 years. Studies that actually follow patients through out their growing years, and survey them yearly or a few times a year, will show far more accurate results. Asking elderly recovering stroke patients to recall 50 years of eating habits seems a little absurd. Although I am sure these patients did the best they could, I’ll bet there were a few inaccuracy in their answers.
2. Selection bias
All of the people questioned were patients of a vascular clinic and were in recovery for a stroke or mini-stroke. These patients had already demonstrated a tendency toward artery blockage. According to Dr. Joseph Raffaele, “Even if it is true that egg yolks cause an increase in plaque area in people who are proven to be plaque formers, that doesn’t necessarily mean that it will cause it in the general population. What they should have done was compare the egg consumption and carotid plaque of the clinic subjects to that of a group that hadn’t had any clinical evidence of atherosclerosis. Indeed, this study suffers from the classic research flaw known as selection bias.”
3. Correlation is not causation
Let’s say all 1,231 patients have memories like an elephant and can remember exactly their egg-yolk-years. How do we really know it’s the eggs that caused the plaque? All we really know is those that had more plaque ate more eggs. We also know that those who ate more eggs, smoked more too. Maybe those who ate more eggs just had more bad habits. Maybe those who ate more eggs also ate more bacon, more white bread, more pancakes, more vegetable oil, or maybe they just ate more food. None of these questions were asked in the study. Since Dr. Spence was looking for an egg-correlation, why would he care about all this other non-important information? We must remember, just because there is a correlation between two things does not mean one causes the other. It just means there is a correlation and maybe we should ask more questions.
4. Like…What kind of eggs were they eating?
In my eyes, the quality of the egg is very important when it comes to health. Pastured-organic eggs from chickens fed worms and grass are going to produce a far different egg than a conventionally-farmed chicken living in a battery cage (small chicken cages) being fed soy and grains. In fact, in a 2008 study, Dr. Niva Shapira demonstrated how the diet of egg-laying hens could change the nutritional quality of the eggs. Dr. Shapira fed one group of hens a diet high in Omega-6 polyunsaturated fats (corn and soy), while the other group of hens received a diet low in Omega-6 fats and additional anti-oxidants. Dr. Shapira showed how eating two high corn-soy eggs a day elevated oxidized LDL (bad) cholesterol by 40% in normal, healthy individuals. The individuals who ate two low Omega-6 eggs a day had normal levels of oxidized LDL cholesterol. The Spence study did not clarify what kind of eggs any of these individuals were eating. So is it really the eggs that had a negative effect on the body or is it the crap the hens were eating that had the negative effect? Hmmmm?
5. How did they cook their eggs?
Three eggs cooked in vegetable oil (which is high in polyunsaturated fats/PUFA) vs. three eggs cooked in coconut oil are going to produce an entirely different effect on your body. As I have expressed time and time again, PUFA’s oxidize easily under high temperatures and within the presence of oxygen. Coconut oil, which is a protective saturated fat, is much more stable. According to Dr. Ray Peat:
“When oxidized polyunsaturated oils, such as corn oil or linoleic acid, are added to food, they appear in the blood lipids, where they accelerate the formation of cholesterol deposits in arteries (Staprans, et al., 1994, 1996).
Stress accelerates the oxidation of the polyunsaturated fatty acids in the body, so people who consume unsaturated vegetable oils will have some oxidized cholesterol in their tissues.”
In addition, overcooking the yolks can oxidize the cholesterol in the egg. Runny yolks are usually considered the best alternative when preparing your eggs. So if you are not into eating raw eggs in the morning, soft boiling, sunny side up, or poached eggs are best.
Essentially, what all this means is it may not be the eggs themselves causing the plaque build-up but the addition of certain cooking oils, or the overcooked yolk, that could be contributing to increased oxidized cholesterol in the arteries.
6. Did the patients exercise?
This is a very important question Dr. Spence left out of his study. Why is it important? Because we now know that exercise decreases the chances of artery blockage and other heart issues. Maybe the people who ate fewer eggs also exercised more. So maybe it was not the eggs at all, but maybe the lack of exercise that led to the increased arterial blockage. Of course, I am making some guesses here. But we have to consider everything when making such a strong claim.
7. Thyroid and liver health.
The health of your thyroid and liver plays an important role in cholesterol plaque build-up in your arteries. Your thyroid is responsible for producing thyroxine (T4) and a small amount of Triiodothyronine or T3(the active form of thyroid) in the body. Most of T4 is converted into T3 in your liver. T3 is responsible for converting cholesterol to all your steroidal hormones. Without T3, cholesterol cannot be converted, which can lead to a cholesterol back up and increased cholesterol levels. Increased cholesterol is a major marker for hypothyroidism. This back-up could lead to higher levels of oxidized cholesterol if healthy levels of the thyroid hormone are not met.
“Although cholesterol is protective against oxidative and cytolytic damage, the chronic free radical exposure will oxidize it. During the low cholesterol turnover of hypothyroidism, the oxidized variants of cholesterol will accumulate, so cholesterol loses its protective functions.”
–Dr. Ray Peat.
Let us remember cholesterol is protective, is part of our immune system, and is essential for our bodies to live. The liver produces 80% of our serum cholesterol, the other 20% comes from our diet. A recent study from Harvard Medical School showed that dietary cholesterol has little effect on serum cholesterol. Our body self-regulates: if we do not consume cholesterol, our bodies will make it. Therefore, whether the cholesterol comes from our diet or from our own liver, it will rise when we are in a hypothyroid state. Thus, the great egg is getting all the blame when, in all reality, it may be the health of the patient’s thyroid and liver that is more of a contributing factor.
Who knew we had to look at so many factors?
To be honest, there was so much wrong with this study that I am surprised it actually got published. Yet, studies and claims like this are published every day. Trust me, I read a lot of research articles. And for every article I read supporting a claim, I’ll read another one saying the exact opposite. The truth is most studies testing foods have problems, whether it’s the population’s health, the use of animals, a questionnaire, a meta-analysis, the quality of the food being tested, other foods being eaten at the same time, the length of the study, who is paying for the study, research bias, patients’ memory and honesty, or the overall interpretation of the results. Ugh. It can definitely get a little frustrating when trying to decide what to put in your mouth. Knowing all this, I am sure you are still wondering… “Should I be eating eggs?”
Well, here is my take…
Eggs contain carotenoids, vitamins A, E, D and K, calcium, iron, phosphorus, zinc, thiamin, B6, folate, B12, pantothenic acid, choline, potassium, magnesium, copper, manganese, selenium, and are a complete protein. Most of the nutrients, all of the fat and cholesterol and about 50% of the protein is found in the yolk of the egg. In fact, every part of the egg, including the egg-shell can be eaten for its nutritional content. The egg-shell is an amazing source of Calcium. For such a little amount of food, the egg is a powerhouse full of nutrition.
There, of course, have been plenty of studies demonstrating that eating 1-2 eggs/day does not affect plaque build-up in healthy adults. The fourteen-year Nurses study and the eight-year Health Professional Follow study documented the eating habits of over 120,000 men and women collectively. Both studies concluded that eating one egg/day was very unlikely to have a substantial impact on cardiovascular disease or stroke in healthy individuals.
When the body is working optimally and you are taking care of yourself by eating the right foods and exercising, I think consuming eggs regularly is far more healthful to your diet than harmful. Therefore, when deciding to make eggs a part of our daily diet, I would take into consideration the following things:
1. Hens Diet
Be aware of the health and diet of the chickens/hens producing the eggs. Eggs can add value to your diet if they come from a healthy source. Be aware of tricky words food manufacturers use on their egg cartons–words like, “vegetarian diet”, “natural”, and “free-roaming”. Each of these means very little. If possible, buy your eggs from a local retailer at a farmers’ market or direct from the farm. Eggs should be organic, pastured- raised, corn- and soy-free.
2. Cooking style
When preparing your eggs, leave the yolk runny and cook them in the right oils (coconut, butter or ghee). These oils are all saturated fats. They do not oxidize under high heats like PUFA’s and MUFA’s (monounsaturated).
3. Restaurant eating
When eating out at restaurants, limit your egg consumption. Almost all eggs prepared in a restaurant are NOT pastured-organic raised. Almost all eggs cooked in a restaurant will be cooked in some sort of vegetable oil. If you decide to eat eggs at your favorite restaurant, ask for poached eggs or hard-boiled eggs. These will be the safest.
4. Side dishes
Take into consideration the other things you are eating with the eggs. A cup of fruit or pulp-free OJ is a nice complement. A few pieces of bread, bacon and pancakes are not the best of side dishes. Eggs are not a miracle food. They can add to your health or take from your health, depending on what you eat with them.
5. YOUR health
Look at your overall health. If you are hypothyroid, diabetic, prone to heart disease or arteriosclerosis, I would limit the amount of eggs in your diet until you have worked on healing your body and metabolism. If you are a healthy individual, who exercises and eats healthfully, then I say don’t be afraid to eat an egg or two on a daily basis.
Eggs are an important food and should not be avoided. However, you have to be conscious of your egg selection, how you are preparing them, how many you are eating, and the state of your health. Also, we must remember you cannot believe everything you read and everything you hear in the news or on the internet. Question everything (including me), do your own research, and find out what resonates with you. Health and healing are so individualized, what is working for your neighbor may have the opposite effect on you–another great reason to be taking full responsibility of taking care of yourself!
Your Optimal Health Coach,
“Disclaimer: I am an exercise physiologist, personal trainer, nutritional and lifestyle coach, not a medical doctor. I do not diagnose, prescribe for, treat or claim to prevent, mitigate or cure any human disease or physical problem. I do not provide diagnosis, care treatment or rehabilitation of individuals, nor apply medical, mental health or human development principles. I do not prescribe prescription drugs nor do I tell you to discontinue them. I provide physical and dietary suggestions to improve health and wellness and to nourish and support normal function and structure of the body. If you suspect any disease please consult your physician.”
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