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Apr 28, 2007 01:27 PM

EggYolks: What's the answer, Folks?

Here's my quick take on what seems to be the current status of egg yolk (ie cholesterol) research. Does anyone know of recent definitive studies that can help us make decisions about whether to separate the whites from the yolks, or to keep them whole?

Bottom line: we (or, the growing data-centered clinical trial based research community that represents us) just don't know yet, for sure.

Dean Ornish epitomizes one pole of the debate, the cholesterol-free extreme, where they demonstrated 20 years ago that reversal of blood cholesterol was possible with virtually total abstinence from animal cholesterol (and other fats, with total vegetable fat being limited to 10% of calories). Interested parties should consult those findings. Ornish today is living, breathing, lean, active, and vital, and misses out on lots of fun foodstuffs. Dr. Atkins, the polar opposite, is dead from coronary disease.

Research has exploded since then, separating the role of fats from cholesterol, separating saturation features of fats, separating plant sterols from animal sterols. In a premature clamored for attempt to set a "guideline", the Feds came up with 300 mg cholesterol daily intake: one egg yolk.

Then the buzz about Omegas entered the popular mainstream, and the restoration in popular culture and advertising that it was time to absolve and re-sanctify the egg (and yolk) as the Perfect Food with its omegas and vitamin E.

Genetic predisposition is also a hot research topic: are some of us doomed to produce more LDLs than HDLs? Seems so. (We MAKE cholesterol, whether we consume it from animal sources or not).

As to the question: Well, since an egg is the 'perfect storage package' to bring forth the next generation... and the corollary supportive argument for full fat milk, we must consider the differences between early development, where fatty sheaths are being laid down around nerve cells, versus the later life where those sheaths are already established. Thus the "feed the kid whole milk up to the age of two" recommendation.

My personal choice is to use the 300 mg cholesterol per day as a mental monitor. There are days when I delight in the beauty of a perfect soft-boiled egg to my taste, or a deviled egg, but I allow myself also to revel in the beauty of an egg-white omellet, prepared only with sprayed Pam or olive oil.

Wish I had a clearer picture, but at this point it seems that even the experts haven't reached a firm, hard-boiled consensus. Does anyone know of new studies that can assist the cholesterol-conscious egg lovers?

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  1. Studies of the effects on humans of their food consumption are clear and relatively characterized by consensus. Important overall is that many variables are important and trade-offs rather than black-or-white eat this/don't eat this are relevant. If the "experts" are scientists, you will not get a "hard boiled consensus" as to what to eat. If your "experts" are self appointed, you will get absolutes--but these are usually one-sided opinions that people want to hear.

    3 Replies
    1. re: Sam Fujisaka

      Hi Sam,
      The latest published legitimate medical studies, published in 2006-2007, do seem to establish some sort of consensus. I searched the National Library of Medicine database [search was for eggs AND cholesterol] and found, in summary, that eating eggs did not increase serum cholesterol levels, or the incidence of coronary heart disease or stroke. Here's what I learned:

      In July, 2006, The Harvard Heart Letter published an article titled
      “To make an omelet, you have to break some eggs. The dangers of eggs aren't all they're cracked up to be--avoid them if you want, but it isn't necessary.”

      “Myth: Eating eggs is bad for your heart. The only large study to look at the impact of egg consumption on heart disease…found no connection between the two. In this study of nearly 120,000 initially healthy men and women, those who ate one or more eggs a day were no more likely to have had a heart attack or stroke or to have died of cardiovascular disease over a 14-year study period than those who ate fewer than one egg per week.

      “Myth: All of that cholesterol goes straight to your bloodstream and then into your arteries. Not so. In the average person*, only a small amount of the cholesterol in food passes directly into the blood. The liver makes most of the cholesterol that circulates in the bloodstream, largely in response to saturated and trans fats in the diet. Studies dating back to 1950…show that the amount of cholesterol in food generally has a small impact on cholesterol in the blood.

      “Fact: An egg is a good source of nutrients. For about 15 cents, you get 6 grams of protein, some healthful unsaturated fats, and a smattering of vitamins and minerals. Eggs are also a good source of choline, which has been linked with preserving memory, and lutein and zeaxanthin, which may protect against vision loss.”

      * Two groups of people who do need to watch their dietary cholesterol and consumption of eggs are those with diabetes, and those with existing cholesterol problems usually genetic in origin (called hyperresponders).

      “Reputation Rehabilitation: [In the 1960s,] The American Heart Association (AHA)…set an upper limit for daily cholesterol intake at 300 mg a day (200 mg if you have heart disease) and warned Americans to avoid eating egg yolks. There were two big problems with these recommendations. The upper limit of 300 mg a day seems to have been chosen not for a specific scientific reason but because it was half of the average American’s daily cholesterol intake at the time. And the warning on egg consumption was based on the logical — but incorrect — assumption that cholesterol in food translated directly into cholesterol levels in the blood.”

      Here are some other recent medical studies, all from the National Library of Medicine:

      Please note that I did not "cherry pick" articles to support a point of view.
      Articles were sorted recent date first, and I figured we were looking for the
      latest information. Here is the fruit of my labors:

      Regular egg consumption does not increase the risk of stroke and cardiovascular diseases: “No significant difference was observed between persons who consumed greater than 6 eggs per week compared to those who consume none or less than 1 egg per week in regards to any stroke.”
      Source: Medical Science Monitor, Jan, 2007, Epidemiological and Outcomes Research Division, Department of Neurology and Neurosciences, University of Medicine and Dentistry of New Jersey, Newark.

      “Dietary recommendations aimed at restricting egg consumption should not be generalized to include all individuals. We need to acknowledge that diverse healthy populations experience no risk in developing coronary heart disease by increasing their intake of cholesterol but, in contrast, they may have multiple beneficial effects by the inclusion of eggs in their regular diet.”
      Source: Current Opinion in Clinical Nutritrion and Metabolic Care. Jan. 2006, Department of Nutritional Sciences, University of Connecticut, Storrs.

      In a study of 90,000 Japanese men and women, “eating eggs more frequently, up to almost daily, was not associated with an increase in coronary heart disease incidence for middle-aged Japanese men and women.”
      Source: Egg consumption, serum total cholesterol concentrations and coronary heart disease incidence, British Journal of Nutrition, Nov. 2006, Cardiovascular Epidemiology, Faculty of Home Economics, Kyoto Women's University, Japan.

      Even in folks aged over 60, eating one egg per day for five weeks “did not affect serum concentrations of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides, and increased the amounts of lutein and zeaxanthin [known to help prevent age-related macular degeneration, the leading cause of blindness in people over 60].
      Source: Journal of Nutrition, Oct. 2006, Department of Clinical Laboratory and Nutritional Sciences at the University of Massachusetts, Lowell.

      1. re: maria lorraine

        Thanks for the good research, Maria. The last cite is especially interesting.

        Did you run across anything that compared serum cholesterols among vegans, ovo-lacto vegetarians, and full spectrum meat eaters?

      2. re: Sam Fujisaka

        One thing you can be certain of in any case - every "scientific" study profits somebody, whether an industrial lobby, an author, a corporation, a political cause or sometimes, simply a giant ego.

        That's why there are so many studies.

        When in doubt, move to France. They eat anything, enjoy it all and don't die from it prematurely. But you have to put up with all that Galouises smoke....

      3. Here is my take on the whole egg/cholesterol issue.

        I agree with Sam about the one-sided opinions of studies. They are performed in isolation, and do not take into fact the other variables going on. Nobody lives in a bubble. And for how many studies you find supporting a hypothesis, you'll also find studies negating it as well.

        In my personal experience, I have found that the consumption of whole eggs generally do not lead to an increase in blood cholesterol. A case in my point is my father -- had high cholesterol after the age of 40 even though he did not eat eggs, meats, poultry, fried foods, etc. He would have fish about five times a week. He would saute his foods in water and finish off a food with some healthy olive oil, thereby not injesting any oxidized oils. Did not eat sweets, and when he had sugar in some form of cooking, it was unrefined. Took tons of vitamins as well. He also ran for exercise on a daily basis. I'm pretty sure there was a genetic component to his high cholesterol. My younger sister who is a health freak had 200+ cholesterol level since the age of 12 while I (who eats pork, beef, eggs, etc.) hover around 120-150. He had a heart attack (even though he was neurotic about his "healthy" eating habits), and had a triple bypass as a result of it about ten years ago. He resumed his normal diet after the bypass. A few years after his bypass, his cholesterol was still 240-250 range.

        He then sought acupuncture and took Chinese herbs. From the recommendations of his acupuncturist, he reluctantly introduced foods that he thought would kill him such as lamb, duck, quail, pork and eggs. He still ate his rice, beans, vegetables with unoxidized oil, etc. He changed other things such as when he would eat. He was walking everyday as opposed to running everyday. I'm happy to say that his cholesterol is 140, and has been at that level ever since he received acupuncture/herbal therapy/diet modifications.

        In my experience, I have seen many patients who still have high choleterol in spite of them eating egg whites, avoiding meats, etc. There are other factors into play aside from the whole egg issue. In addition, avoiding the egg yolks lead can lead to other problems. Generally, the body functions better when you eat a whole food (whole wheat, whole eggs, etc.) While there may be "scientific" evidence to refute that claim, please see my second paragraph about studies. In addition, many people have food sensitivties to egg whites, which can lead to a host of other problems -- digestive issues, leaky gut, autoimmune disorders, skin disorders, etc. People tend to be sensitive to the whites, not the yolks. And if you eat too much of anything (even if you think it's "healthy") you're at the risk of developing a food sensitivity even if you do not have one at the moment.

        I don't believe too much in the guidelines that the Feds draw for people. Guidelines are just guidelines. And they seem to be changing every once in a while. Are you going to change something just because the government says you should? Everybody is different. There are many other things that can play into factor of your high choleserol level.

        One thing I will say about high cholesterol -- you should avoid beef and beef related products such as butter, non-fat milk, etc. While there may be no "scientific" evidence to back this up, the cow has a tendency to "close" thing in the body, including blood vessels. I have seen many patients improve their cholesterol levels by removing cow related items from their diet.

        1. In my experience, some people are more sensitive to dietary cholesterol then others -- my husband and his family -- they so much as look sideways at an egg or red meats, and it skyrockets. I can eat omelets and cheeseburgers every other day and still be bottomed out. Jeffery Steingarten wrote some interesting stuff about the genetics aspects of it, for Vogue, I think.

          What it boils down too is just being aware of and responsible for your own health -- keep a weather eye to the science, but its more important how your own body deals with things. Within the bounds of deliciousness, vary your diet, and see how your health responds.

          Also, on a minor note - Atkins didn't die of heart disease. He tripped and whacked his head on some concrete.

          2 Replies
          1. re: AnnaEA

            2 eggs a week is the recommendation to avoid high cholesterol-the yolks are baad not the whites-my questions is-how many eggs are in a zucchini loaf??if more than 2 then I am in trouble-if 2 then I can eat one loaf a week and have to avoid other egg additions--this is soo hard-

            1. re: AnnaEA

              It's true about the genetics. My doctor always tells me my cholesterol levels are perfect. I only eat red meat once or twice a month, but I probably eat at least 10 eggs a week. My grandfather was an ox of a man who ate a full dozen eggs for breakfast every morning and lived to 88. My father just had his first checkup in 18 years and at 70 his cholesterol is also perfect. When he told me this, I thanked him for his genes and dug into a nice fried egg....

            2. I am not an expert or a scientist or a nutritionist, so you can ignore my comments if you want. However, my personal experience has been that cholesterol levels are more a result of genetics than diet. I have never avoided red meat, animal fats (butter, whatever), and if I am eating ice cream, give me full fat or don't give me anything at all. My cholesterol levels are, according to my doctor, those of a teenager. I am 56. Of course, I do eat well - lots of vegs and fruits, some whole grains, fish, etc. I believe it is all a matter of balance and good sense. And good genes.

              Quite a few years ago - probably more than twenty, actually - I read somewhere that egg yolks contain lecithin which helps the body metabolize the cholesterol in the eggs. An example of the whole food itself containing whatever is required to properly utilize its nutrients. This makes perfect sense to me. I believe that there is something wrong with dissecting a food into its good parts and bad parts - either eat the whole darn thing, or don't eat it at all. I am not going to argue with people who have experienced otherwise - this is just my own personal theory and it works for me. I will never eat an egg white omelet. Never.

              1. Evan Kleiman of, "Good Food," on KCRW recently interviewed a gentleman who authored a book about eggs. I believe if you go their website, you can pull up the interview from the archives under "Good Food." The interview was very enlightening and informative. The news was good. Seems that if you're relatively healthy (unless you are on a restricted diet, i.e., diabetic, high cholesterol, etc.), one can eat one to two eggs per day without any issues. The new findings reflect a better understanding of how food is assimilated and metabolized by the body, and that the mere comsuming of cholesterol doesn't necessarily equate to an equivalent rise in overall cholesterol levels. I don't want to expand anymore about the interview as you should hear it for yourself.