Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
1 Apr

Dear Mark: Eggs, More Eggs, and Marathon Man

EggsFor today’s edition of Dear Mark, we’re talking eggs, eggs, and marathons. First up are egg allergies/intolerances as determined by blood test. It’s not exactly clear what blood test was used to determine the inflammatory response to eggs, but regardless: the test was done and the reader is now worried about eggs, previously one of her favorite foods. Can she reintroduce eggs? Should she even worry at all? Next are eggs and blood lipids. Our reader’s naturopath has warned against four times daily egg consumption because of elevated LDL, and she wants to know if there’s really any reason to follow the advice. I lay out some of the evidence in favor of egg consumption; hopefully it’s enough to satisfy. Finally, I discuss the curious case of Stefaan Engels, the man who ran 365 marathons in 365 days. Does he discredit my whole view of fitness, chronic cardio, and endurance training? Should you therefore take up daily marathoning? Read on to find out.

Let’s go:

I had blood work done that showed eggs, and especially egg whites, were the number one food allergy causing inflammation in me. Eggs are one of my very favorite foods and because of the tests I have all but eliminated them from my diet. Is it possible that eggs can be reintroduced into my diet after some time on the primal blueprint?

Thank you for any suggestions!


I’d be interested to hear exactly what this blood work consisted of, because if it was IgG allergy testing, I’m not very convinced. Egg allergy is one thing, where you have a bite of food containing eggs and end up going into anaphylactic shock. That’s bad, that’s dangerous, and you can’t really ignore it. If eggs are an imminent threat to your life and you feel awful eating them, by all means, listen to the blood work and eliminate the eggs. The simple fact that they are one of your favorite foods, however, makes me think that eggs aren’t having a noticeable impact on your health.

If it was an IgG allergy test, there are serious doubts as to its accuracy and usefulness in identifying allergies or sensitivities. Chris Kresser, in one post, recounts how he once received back completely different results after sending two vials of his blood to the same lab for testing. And one study even found that every subject tested positive for ovalbumin-specific (egg white) IgG levels, whether they had active egg allergies, resolved egg allergies, or were completely free of egg allergies. The authors suspect that “strong IgG responses to OVA may be a normal physiological response to a protein frequently ingested from infancy.” Another study found that children who had higher IgG responses to egg protein as infants actually showed greater tolerance of egg protein later in life. If everyone has positive responses to egg-specific IgG levels regardless of allergic status, what’s the point of testing? And if higher IgG responses to proteins have even been shown to indicate greater tolerance of said proteins, are IgG tests really useful in determining intolerances?

How did they determine that they’re causing inflammation in your body? Did you get a C-reactive protein test? Did they test for specific inflammatory cytokines? Or do you get symptoms of inflammation upon egg consumption – achy joints, irritated skin, gastrointestinal upset? Or is the “inflammation” an abstract thing purely represented by numbers on a lab test? A blood test is rarely sufficient, particularly absent subjective symptoms.

You may very well be sensitive to eggs. Many people are. But most people who are sensitive to eggs don’t consider them a favorite food. You could be suffering from inconspicuous inflammation, doing damage to yourself without really knowing it. But in the absence of obvious symptoms, I’d hesitate to banish eggs entirely from your diet. Eggs are nearly unparalleled in the nutrition realm. They’re an excellent source of highly assimilable protein and vitamins like A, choline, K2, and folate, and they can be a good source of omega-3s if the hen’s diet is right.  Take them out for a few weeks to see how you react, sure. Nothing wrong with an elimination diet. That way, you’ll get actual answers in about 30 days, and you’ll be able to determine whether or not eggs are causing problems.

Look into your intestinal permeability, too. Oftentimes errant food proteins worm their way into our blood stream by way of an overly permeable intestinal wall, thereby prompting an immune response. Eat more gelatin and bone broth, consider probiotics, and eat some fermentable fiber to improve your gut health.

One final note: if it’s egg white you’re worried about and sensitive to, just eat the yolks. The yolks are the best part, anyway. If you trust your eggs, there’s no better multivitamin than a few raw pastured egg yolks in the morning.

I am seeing a naturopath and she is a bit worried about my LDL cholesterol, and is concerned I am eating too many eggs (3-4 for breakfast every day and the odd extra one with dinner). She says she normally doesn’t worry about eggs but in my case maybe it’s time to pull it back a bit….but hang on, everything I have read in paleo-land tells me that eggs are fine.

She said another comment that intruiged me, that because I fry my eggs (in coconut oil) or make an omelette that the yolk is exposed to air and they oxidise, and this may be the problem. She recommended cutting back to 2 eggs a day and only poaching under water or boiling. Have you ever heard such a thing and could it have any credence…or is it time to find a new naturopath!

I am one of your many readers from Australia and send you a big thanks for the work you do from Down Under.


The vast majority of the evidence shows that egg consumption has either no effect or a favorable effect on serum lipids, particularly if you’re eating low-carb/high-protein (terms which are usually synonymous in the medical literature):

Dietary cholesterol from eggs increases HDL in overweight men on a low-carb diet and reduces markers of metabolic syndrome.

As part of a high-protein diet, egg consumption improves blood lipid and blood glucose profiles in type 2 diabetics.

Heck, if you’re eating low-carb, eggs might actually make it work even better than a low-carb diet without eggs, probably due to the cholesterol increasing HDL and improving antioxidant function. Or, it might be the increase in HDL and LDL particle size (and probable reduction in HDL and LDL particle number) along with the higher levels of circulating antioxidants doing the trick. Or both. Either way, eggs fit quite nicely into a Primal eating plan.

Of course, you could be a rare poor responder to eggs. Some people experience increases in cholesterol (although it’s usually both HDL and LDL, so it ends up a wash in a sense). It probably won’t hurt to spend a few weeks at a lower daily egg intake just to see what happens to your lipids. They might drop. You might feel even better than before. They could also drop, and you end up feeling worse. After all, cholesterol is converted into important hormones like pregnenolone and testosterone and vital prohormones like vitamin D. Lipoproteins also deliver nutrients (beyond just cholesterol) to cells. Lower cholesterol – even LDL – isn’t always better. Don’t ignore subjective measurements of health, like energy levels, libido, workout performance, and general feelings of awesomeness.

Oxidized cholesterol from overcooked eggs might be able to increase the portion of oxidized cholesterol in your LDL particles, but I haven’t seen any evidence that it would increase circulating levels of LDL. It’s just that the LDL in your LDL particles might be a bit more oxidized and therefore prone to trigger atherosclerosis. Overall, I think the fear of oxidized cholesterol because you cooked up an omelet is overblown. High-heat, high-pressure spray drying of eggs? Yeah, that’ll oxidize the cholesterol. Cooking them up in coconut oil? Scrambling and subjecting them to a hot buttered pan for a couple minutes? I don’t think you have much to worry about.

That said, I am quite partial to soft boiled eggs. I just pop three or four in my pressure cooker with a cup of water, set it to steam for three minutes, and immediately immerse them in cold water. The white comes out soft, smooth, and fully-cooked while the yolk remains warm and runny. I mostly do it because it’s easy (I can just set the timer and walk away) and tasty (a runny yolk is paramount), but I can see it being “healthier” in that it eliminates any chance of cholesterol oxidation (not that I think we need to worry too much).

How do you explain Stefaan Engels? He ran a marathon everyday for a year, ate whatever he wanted, and showed no muscle or cartilage damage.


Engels is certainly impressive, but he’s pretty easy to explain.

He’s an outlier, well-suited for marathon running. I’ve never argued that you can’t run marathons and be healthy. I’ve merely argued that running and (most importantly) training for marathons at an elite level usually means avoiding other beneficial ways to train, and results in aches, pains, and injuries. Just because lots of slow moving, some sprinting, and heavy lifting (and even some endurance work alongside) builds more lean mass and more well-rounded fitness in a fraction of the time doesn’t mean marathoning means certain death.

Not to take anything away, but it was a parlor trick. He took an average of four hours to complete each marathon, which means he was taking a little over nine minutes per mile. For him, an elite endurance athlete (and accomplished triathlete), he probably never got past 60% of his max heart rate, which might not even qualify as chronic cardio in his case. A 9+ minute/mile pace is far better than most people could do, but it’s not very hard for him. He was taking it relatively easy. Engels’ best time was 2:56, and 4:00 is an easy jog for a guy with a sub 3:00 marathon.

As for eating whatever he wanted, exactly! When you’re training for marathons like I was, you have to be willing to shovel just about anything in, purely for the easy and quick calories. Superhuman levels of athletics often require superhuman levels of consumption – just look at Michael Phelps.

Nothing against Engels or his feats, mind you. But his situation really isn’t applicable to the average Joe, for whom I write my books and my blogs.

There were runners in the 1970s who regularly did 250 training miles a week and then raced hard and fast. My friend Dave McGillivray ran across the USA (3,452 miles) in 80 days. He turned out fine, but most of the other guys are dead or ailing now. Many of my triathlon buds had no signs of damage during their careers, but years later had big problems.

So yeah, you can do it, but it doesn’t mean you should.

That’s it for this week, guys. Thanks for reading and be sure to leave a comment!

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. Dear Mark…I need to know how to cook eggs in a pressure cooker. Last time I used one, a 15 minute cool down period was required before removing the lid to avoid an explosion of boiling hot liquid. Also, how does one eat soft boiled eggs without toast? This was one of my favorite meals before going paleo and I haven’t come up with a good substitute yet.

    Regarding supermarket eggs…the over-the-top food laws here in Canada require just about everything to be dipped in bleach before being sold. They’re even promoting that practice to farmers selling their produce in farmers’ markets even tho it’s not law (yet). A friend once told me that supermarket eggs are also dipped in a bleach solution. I can’t prove this and don’t know for sure if it’s true but it would be worth checking out. Since we started eating eggs from our own chickens, we’ve found out how good eggs can be.

    Karen wrote on April 2nd, 2013
  2. Another MDA coincedence. Yesterday I was considering emailing and asking about eggs and what may be an excessive amount.
    I had a dozen boiled and ate them all in about an hour. It’s been a long time since I’ve eaten eggs regularly. They used to be a staple for me and are still a favourite food. Now when I eat them I want to stuff myself.
    Conventional eggs in a store here sell for $1.95/dozen (one of the few foods I find affordable) so I’m considering making them my main staple. 2 dozen would be food for a day.

    Animanarchy wrote on April 2nd, 2013
  3. My wife and I have taken to eaten dishes with raw eggs in order to get the most benefit from the yokes. I’m glad to hear so much info supporting eggs as an amazing source of nutrition!

    Jason Stanley wrote on April 2nd, 2013
  4. @biskitball — and all others — just for (my own) edification’s sake, I checked out the nutritional data for a conventional egg, and there’s less than 1 gram of PUFA in each egg, out of about 5.5 grams of total fat, the biggest proportion of fat actually coming from MUFA (2.1 grams) then saturated (just under 2) [and no I don’t know where the other mystery 1 gram of fat went to/or what it is) — BUT the point is this: even eating 2 or more eggs a day, doesn’t amount to much in the way of PUFA — and if you’re eating Omega 3 eggs (chickens fed flaxseed) then you’re getting a good balance of Omega 3’s to 6’s anyway … I probably eat a dozen (organic, Omega 3) eggs a week, and my blood lipid readings at the age of 52 — and with some genetics weighing against me in terms of family histories of high cholesteral — are EXCELLENT. oh and just have to say how much I love eggs and their versatility for meals morning, noon or night – poached, over easy, lightly boiled in a salad, or as omelettes — virtually any way. Sometimes I’ll have an omelette stuffed with vegetables like broccoli or spinach and a little (organic, grass fed, raw milk) cheese for dinner.

    am_stjohn wrote on April 2nd, 2013
  5. I used to have a terrible egg allergy to the point where my throat would become itchy and my face would turn red. I did my best avoid them, especially the egg whites, in order to avoid that very uncomfortable feeling. That was, until I went primal/paleo and took the grains out. Now I am 100% fine with eggs. I eat 2, 3, sometimes more each day without any issue. I have no idea why this has changed so dramatically but I’m not complaining. It’s just gone.


    Tim wrote on April 3rd, 2013
    • Speaking of eggs- made incredible Easter eggs this year. Google marbled Easter eggs from southern living. Basically they were pickled with beets and it was the actual egg that was colored not just the shell! Plus u get pickled beets to boot! It does call for sugar ( used coconut sugar). Delish and gorgeous!

      Andrea wrote on April 3rd, 2013
  6. Proteins in the egg white are different for each species of bird. In my case I have a chicken egg intolerance, but have no issue with duck or quail eggs. If nothing else, the chicken egg problem was a great excuse for me to raise my own ducks.

    Wifezilla wrote on April 3rd, 2013
  7. I can attest to the severity of egg allergies as my daughter has a life-threatening allergy to them. And her IgE test absolutely shows it. She gets a skin test and blood test every year (.35 is considered allergic, 6.00 is the top of the scale, she measures anywhere between a 10.00 and 19.00). I absolutely believe in the test’s ability to pick up on subtle allergies and intolerances. Please don’t discount the test… It can be one piece of information in beginning to figure out how to fix issues in one’s health.

    Currently we rely almost exclusively on our chiropractor for our healthcare except for our annual trip for vaccinations (which don’t get me started on how I feel about those who don’t vaccinate). He has helped our family’s health much more than our MD who only wanted to prescribe pills for everything.

    I would love to switch my whole family over to primal, but I’m still not sure about my kids. I do believe it would be best for all of us, but not sure how we would go about it. S
    Dinners I can handle… But what do you send in a school lunch? And what do you do for breakfast without eggs?

    Jen wrote on April 10th, 2013
  8. In the past 6 months, I’ve been addressing some things, and with success. As a result I’m now back in karate. I train 5-6x a week simply because I love it and also because I will be competing in Brazil in 2014. Each class is about 50 mins. The team practices are 3 hours (but only every few weeks).

    Is this considered anything extensive or hard? Would a 150g cho still be good enough for optimal health/performance? I will stick to having varied effects from eating before class and not after or not eating before class but eating afterwards for the two different effects you discussed these strategies can have.

    I also walk quite a lot, but for the walking I find I can walk longer if fasted anyway. Soon I might not be able to walk as much as I’d like due to heavier work schedule. (This saddens me, but the $$ is nice too).


    Zorica Vuletic wrote on July 12th, 2013
  9. Alright internet, I need some help. I am looking for a healthy primal breakfast for a house with small children, one of which has an egg allergy. Any suggestions for recipes, or even just main ingredients would be greatly appreciated.

    Chad L. wrote on July 25th, 2014
    • Ok, I’ll bite. I don’t know if your kids like smoothies but my son will drink one some days. I put in fresh frozen fruit (like peaches) and then a tiny bit of milk, a couple of tablespoons of yogurt, a dab of maple syrup for sweetness, some vanilla for smoothness and some sort of protein, whirr that up in the blender and Viola! a wonderful smoothie. It’s carb heavy with the fruit but kids will burn them more than us grandma types so no prob. We use eggs for the protein but there’s gotta be something that you could drop in there for that, or maybe just serve with a side of bacon? :-)

      2Rae wrote on July 25th, 2014
  10. Good call! I think I’ve got all those things on hand…including the bacon :)

    Chad L. wrote on July 26th, 2014

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