T Nation

Shouldn't Scramble the Yolk?


I like to make giant omlette's with 8 egg whites and one or two whole omega 3 eggs.... but I heard that cooking the yolk this way and exposing it to heat kills many of the healthy nutrients in the yolk, such as leichin (spelling?) and thus kills all the "good" cholesterol benefits..... is this true?

Am i doomed to have to resort to soft boiling?


No, that's ridiculous. Maybe a small amount. But you'll still be getting plenty of good stuff.


I personally try to maximize egg benefit; i.e: I make egg white omelets and swallow the yolk raw. The little yellow sacks are gorged with vitamins and minerals which aren't particularly fond of heat.


there is an interview with a guy named Dr. Mercola somewhere in the archives, who talks about this exact question.

I like to make an eggwhite omlette, and then either put the raw yolks on top after it's done cooking, or just toss the yolks into a shake. The heat from the egg white omlette is enough to make them taste fine, without scorching them so as to denature all the wonderful nutrients inside.


Excellent idea! How do you separate your egg whites, though?


If I remember correctly, I think Mercola used to have some theory about not cooking the yolks because cooking them - in addition to reducing their nutritive value - creates free radicals, or something like that. I'm not sure of the veracity of this though.


is soft boiling ok?


i just do it with the egg shell halves, pour the whites into a cup or bowl, and the yolks into a separate cup or bowl. then cook the whites, and gently drop the yolks on top after the whites are done. tastes like "sunny side up" eggs at any diner.


sounds simple enough. I'll give it a shot tomorrow morning.


That's what I do - a good compromise, and also convenient, delicious. But I make mine very soft.


so the same vitamins and minerals which are not really affected by heat in other cooked animal protein foods are all the sudden destroyed by the heat?

somehow that just doesn't follow. research is all over the map on this issue. the only conclusive thing is that the heat denatures the protein. and quite frankly that is irrelevent.

note: lixy, this is not a personal attack, just the post was the most clear for why not and i disagree.

in short, make sure you eat the egg and the whites are cooked, other than that make them however you want.

i looked up the nutrient values for different cooking methods and all vitamins and minerals are there in the same amounts as fresh raw eggs. the only thing that i could not address is the choline denaturing issue, but i don't believe it to significantly occur.

looking at the list of choline containing foods, one sees cooked fish and beef after the eggs with reasonable choline content, so i have to assume it will not be destroyed to a large degree in cooked eggs.



Just so we're perfectly clear, I made the comment only based on what I read around here (and elsewhere). Hence, the non-categorical tone of my post.

Now, I do know that some vitamins get destroyed with heat. I also know that one of those happen to be vitamin E and, is present in the yolk.


all tocopherols were present in similar levels regardless of cooking method or fresh in the SR20 database.

the only thing that didn't match close is folate which was 15-25% lower in scrambled eggs vs. fresh raw, hard boiled and poached. the difference in levels per egg is roughly equal to a large leaf of spinach. 3 scrambled eggs will still deliver over 12.5% of the DRI on its own. the difference in folate between 3 scrambled eggs and 3 of any other type is the folate contained in 10g of spinach.

interesting sidenote: if you do the math on the scrambled eggs in the database, they were made with around 14mL of whole milk per egg, or half a fuid ounce. this explains why the protein, carb and fat content are slightly higher and the weight is 61g per large egg vs. the normal 50g.


here is what I read at a different site:

June Russell's Health Facts
Eggs and Cholesterol - Controversy and Deception
The Egg Story: We have heard studies showing that eggs in the diet will raise cholesterol, but no reports on the type of eggs that were used. According to Artemis Simopoulos, MD, nutrition expert and president for the Center for Genetics, Nutrition and Health, in Washington, D.C. and author of the book, "The Omega Diet," those eggs from free range chickens will not raise cholesterol. This study was in the New England Journal of Medicine. The factory supermarket eggs have a ratio of omega 6's to omega 3's 3 20 to 1, whereas the eggs from free range chickens are perfectly balanced Ç¿ 1 to 1. Too much omega 6 increases rates of many diseases. Meats and milk products from free range animals also increases disease rates. Also years ago when they measured cholesterol in shrimp, they measured not only the cholesterol, they measured all the other sterols, so they came up with a high figure. Now that we can distinguish the various sterols, the cholesterol in shrimp is much lower than originally determined, so even if you have heart disease it is all right to eat some a couple of times a week.
{Artemis Simopoulos, MD, on the People's Pharmacy, Show #368, Public Radio, Jul. 21, 2001}

After 40 years of being told that the cholesterol we eat goes right to our heart, now we find that it is not true. In two studies there was no difference in risk among those who ate eggs less than once a week and those who ate more than one a day.
{"A little egg on the face of it," NutritionNewsFocus, Feb. 15, 2001}

Cholesterol is a white, waxy substance found naturally throughout the body, including the blood, and is essential for good health. It belongs to a class of compounds called sterols. It is not a fat, but a closely related substance, however, it is often called a blood fat, or lipid. It is found naturally in every cell of your body. Each cell contains enzymes used for the production of cholesterol, and when the inside of the cells are cholesterol depleted, they are less efficient. Cholesterol is also essential for the development of our hormones and brain function, providing the stabilization of neurotransmitters. Depression, agitation and irritability can occur when your body doesn't get enough cholesterol.

Insulin is the major hormone directing the overproduction of cholesterol in the body. High-insulin levels are caused by consuming a diet that is insufficient in proteins and fats, while eating excess carbohydrates. Other causes of high-insulin levels are stress, caffeine, alcohol, tobacco, steroids, and aspartame. This over production of cholesterol contributes to the formation of the damaging artery plaque that leads to heart attacks and strokes, say Diana Schwarzbein, MD and Nancy Deville, authors of the book, "The Schwarzbein Principal."

Cholesterol is so necessary to bodily functions that regardless of dietary intake, the body produces about 1,000 mg of cholesterol daily. Our body actually accelerates cholesterol production if we don't eat enough of it. Not only are cholesterol and fat essential to life, but if you don't eat these in your diet, you will be on the accelerated metabolic aging track toward disease and an earlier death, say Diana Schwarzbein, MD and Nancy Deville. According to Ann Louise Gittleman in her book, "Supernutrition for Menopause," what leads to high blood cholesterol is the lack of other nutrients, such as chromium, magnesium, vitamin B, and omega-3 essential fatty acids. These are all necessary for the metabolism of cholesterol. More than 80% of your daily cholesterol production comes not from your diet but from your own liver. So a high-carbohydrate, low-cholesterol diet guarantees a steady overproduction of cholesterol within the body. Negative press seems to live forever, even when positive research to the contrary exists.
{"Is dietary cholesterol really public enemy #1?" Women's Health Connection, an educational division of Women's International Pharmacy, 1998}

When cooking an egg, the cholesterol in the yolk is altered when simultaneously heated and exposed to air. Therefore, eggs should be cooked without breaking the yolks (i.e. poached, boiled, over easy, etc.), instead of scrambled or made into omelets. A raw blended egg should be drunk fairly quickly, or refrigerated, because leaving it out at room temperature will start cholesterol oxidation, albeit more slowly than by cooking.
{Health Scientist Panelist, Allan Spreen, MD, on e-Alert, April 3, 2003}

Also in "To Your Health," 2002, Dr. Spreen says that the original researchers did not even use real, whole eggs: they used powdered eggs. The lecithin in the eggs had to be heated (altered before ever being used in the research), thus destroying the healthy, naturally protective lecithin only available in the real whole egg.

When one heats the egg yolk, changes occur in the fragile elements that serve to support the vital life force within the egg. The egg yolk, in many ways, is not very different from your own cells. Once your temperature goes above 105 degrees, you will start to suffer serious health problems. Similarly heating the yolk above 105 degrees will also start to cause structural changes in many of the highly perishable components in the yolk. The most obvious one is cholesterol. The more the yolk is heated, the more likely oxidation will occur. Our blood vessels do not have receptors for cholesterol, only for oxidized cholesterol. So, you can eat as many eggs as you like, without worrying about cholesterol, as long as you don't cook the yolks.
{"Biotin, the forgotten vitamin," mercola.com, July 2002} Editor's comment: Dr. Mercola's website is one of the most visited health sites in the world.

In a study reported in the 2001 issue of the Journal of Nutrition, researchers from Kansas State University have shown that for the first time an ingredient in eggs actually keeps the artery-clogging cholesterol from getting into your body. Phosphatidylcholine (PC) in eggs actually stops a significant amount of cholesterol from entering the bloodstream. This could be very good news for egg lovers, especially since eggs are packed with other healthy goodies: protein, vitamins A and E, B-6, B-12, and folate.
{"Eggs might not be so bad after all, ingredient stops cholesterol from getting into the body," webmd.com, Nov. 2001}
{"Nutrition Hints # 592, Betty Kamen, PhD, and Dr. Michael Rosenbaum, MD, 2001} Editor's comment: phosphatidylcholine is a substance that also prevents memory loss as we age. The first experiments that maligned eggs as a cholesterol threat were conducted years ago with dried egg yolk. Many studies since then demonstrated that eating whole, fresh eggs does not have the same effect.

Lecithin is a naturally occurring phospholipid that is required by every single cell in your body. Call membranes, which handle the flow of nutrients in and out of the cell, are composed largely of lecithin. Eggs are one of the richest food sources of lecithin. This nutrient is partly responsible for rescuing the reputation of the egg. Scientists at Kansas State University were the first to publish evidence that lecithin actually reduces the absorption of cholesterol. {"What is . . . lecithin?" Nutrition & Healing e-mail, Amanda Ross, Apr. 2004}

Egg yolks can inhibit cells from sticking together (platelet aggregation) and also prevent blood coagulation, two major risk factors for heart disease and stroke. Egg yolks prohibit platelet aggregation in a dose-dependent manner, meaning the more you consume, the more effective the results.
{"Egg yolks against blood coagulation," Hint #1369, Nutrition Hints, Betty Kamen, PhD and Michael Rosenbaum, MD, Dec. 2003, as reported in Biological and Pharmaceutical Bulletin, 2003}

Raw whole eggs are inexpensive and are excellent source of high-quality nutrients. Many of us are deficient in high quality protein and fat. Although eggs are generally one of the most allergic foods that can be eaten, I believe that this is because they are cooked. If one consumes the eggs in their raw state, the incidence of egg allergy virtually disappears. Heating the egg protein actually changes the eggs' chemical shape.

There are suggestions that one should not eat raw egg whites. This is because raw egg whites contain a lipoprotein called avidin that is very effective at binding biotin, one of the B vitamins. The concern is that this can lead to a biotin deficiency. The simple solution is to cook the egg whites as this deactivates the avidin. The problem is that this cooking also deactivates nearly every other protein in the egg white. Although you will still obtain nutritional benefits from consuming cooked egg whites, from a nutritional perspective it would seem far better to consume them uncooked. There is a lot of biotin in the egg yolk, one of the highest concentrations of biotin found in nature, so it is unlikely that you will have a biotin deficiency if you consume the whole raw egg, yolk and white. However, it is clear that if you only consume raw egg whites, you may develop a biotin deficiency unless you take a biotin supplement. Note: be aware that when pregnant a biotin deficiency is common and eating raw eggs may make this worse)
{"Raw eggs for your health,, Major Update," Dr. Joseph Mercola, Mercola.com, Sep. 2005}

Uffe Ravnskov, well known expert on cholesterol, and author of the book, "Cholesterol Myths", adds the comment "The idea about oxidized cholesterol is yet another myth used to explain away the many studies that have failed to find an association between high cholesterol and CVD. Oxidized cholesterol is a risk factor only, probably reflecting lack of antioxidants or excess of free radicals in your body. The amount of oxidized cholesterol produced by heating eggs is trivial. And the main cause of an imbalance between omega 3 and omega 6 is a high consumption of vegetable oils from corn and sunflowers."


Thanks Skinnymuscles, great post! I'm going with Uffe on this one - I respect him a great deal. His book, "The cholesterol myth" is absolutely fascinating.

Also, since I can't find any mention of the oxidation/free radical connection on Mercola's site anymore, perhaps he changed his mind about it.

Anyway, from one egg freak to another, cheers! ~katz


denaturing of a protein changes its shape and inactivates any biological activity it could have due to its native structure. the only way for it to affect you in any other way is through the digested peptides as some of these short chains of amino acids have the ability to trigger allergic responses. this is true of both whey and casein digests as well as peptides formed from wheat, soy, and corn. it is the most likely trigger other than allergies being triggered by intact proteins which are part of RAW eggs.

Avidin is a glycoprotein, not a lipoprotein (lipoproteins are involved in fat transport and metabolism - the distinction will be very important near the end of this post as you will see):

also, the protein in raw eggs is around 50% digestible, while in cooked eggs it is around 91%. Wikapedia would have told you this:

as for dr. mercola, although he promotes numerous healthy habits and good nutrition, often he goes beyond what is clearly supported and is in my opinion a fear monger. that said, i often hardboil eggs so the yolk is only half done. not so much for misguided OCD actions as i enjoy that particular consistency sometimes.

Any way one eats whole eggs of the omega3 or free range vareity in which the whites have been cooked is pretty much the same. Add a fish oil pill per egg and some veggies and you have a perfectly balanced no-digestible-carb meal with much greater micronutrient density than most 'healthy' meals (biotin included since avidin is denatured and thus deactivated by cooking - 3 eggs will net you 2.5 times the DRI).

The fats are also balanced in this meal with 1/3 sat, 1/3 mono, 1/3 poly - around half o3 and half o6, exactly what has been shown to promote an optimal blood lipid profile in normal healthy adults regardless of total fat intake as long as excess calories are not consumed. There is a thread with over 7000 post discussing such macronutrient ratios applied to the whole diet.

There is another where one member had an intake of 3-5g of cholesterol a day and total levels were 118 and 121. That's right, 10-15 times recommended intake and optimal blood parameters.

This may seem weird until you consider that dietary cholesterol is a steroid molecule (basically AAS with a carbon tail at the C18 position instead of a methyl group). Its intake in normal healthy adults does not correlate with blood cholesterol because blood cholesterol is not really cholesterol, but a big ball (called lipoproteins) that delivers fat and cholesterol (The amount of the steroid cholesterol absorbed is independently controlled by an intricate system involving the liver and gallblader.) to the body via the circulatory system.

And of these, LDL or bad cholesterol is thought to be a culprit of most diseases related to inflamation. LDL goes up with carb intake more so than fat intake, though trans fats and poor fat balance will contribute too as will over eating.

But even LDL is not all bad. The newer research shows that what matters is the size of the average LDL with larger LDL being highly correlated with better health and functioning. The function of LDL sheds light on why this is so. LDL is basically a fatty acid delivery vector, so the more small LDL there are, the more fats have been released in your peripheral blood vessels, conversely larger LDL means that the body is only releasing a little fat which it can handle and is the preferred energy source during low level activity.

The larger LDL also correlates with increased HDL or the 'healthy cholesterol. This lipoprotein's function is to collect excess fats and cholesterol (steroid) deposited by LDL. Thus higher levels of HDL and large LDL indicates that the body has the ability to meet its energy needs while not dumping the excess as the high concentration small LDL and low HDL milieu. It is the excess deposition of the latter state that characterizes most modern health problems and is not related to fat intake, but more so high carb intake, poor fat balance, poor micronutrient composition of contemporary diets, and low animal protein intake (a slightly influential, but still important overall variable).


OK thanks for the post, but I am still confused about the whole cooking thing. Can I make my omlette's without ruining the vitamins in the yolk, or should I do an egg white omlette, with a hard boiled or soft boiled or sunny side whole omega eggs on the side?


just eat more of them then


the only vitamin that is clearly lower is folate in scrambled eggs, other cooking methods have the same level as raw fresh eggs. this is not really significant. other than that you are going to see the same vitamins and minerals regardless of how you cook it, but if you cook it protein availability will almost double.

eat the eggs any way you want. you will get the same nutrition regardless. it is a matter of preference. as long as the whites are cooked, you are good, runny yolk, cooked yolk, all the same, vitamins will not be ruined.

you should just eat the whole egg regardless of how you do it, whites are protein only, all the nutrients are in the yolk and aren't going anywhere but your stomach.


I didn't see it mentioned so I'll say it. There are "bad" forms of HDL too, with the "bad" ones being smaller, similar to "bad" LDL being smaller. It's sort of a function of total lipoproteins in to blood. If you have a certain amount of cholesterol to be transported by high and low density lipoproteins, you'd be better off having less larger lipoproteins than you would having many smaller ones. As mentioned, plaque buildup and atherosclerosis of arteries is related to insulin. Much of what was said in this thread is great information.

On a side note, I get a couple grams of cholesterol per day, and since doing this and supplementing with fish oils and eating better quality meats my health has noticeable improved, cholesterol profile included.