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

Seasonality for the Birds

Last week, we determined a common thread of seasonality running through historical fructose consumption. Warm weather with plenty of sunshine generally meant fruit was available. Those living in the tropics (as we humans did for most of our history) thus had year-round access to sweet fruit, while cold climate Grok had seasonal, intermittent access. Plus, there are many symptoms shared between folks with vitamin D deficiency and fructose-induced metabolic syndrome. Eating fruit seasonally (if you’re into that sort of thing) in the modern world, then, probably involves getting some sunlight with your berries.

What about other clearly seasonal foods – can they be consumed freely and wantonly?

Consider birds. The bird is especially sensitive to environmental and seasonal fluctuations, as anyone who’s ever been woken up by hungry birds chirping at the morning light can attest. You’re all familiar with the “flying south for the winter” phenomenon, and you’ve probably seen the highly efficient flying V formation employed by migratory ducks or geese.  They’re just following the food. Ever watch “The Endless Summer”? It’s like that, except with grubs and seeds instead of big waves. Not all birds are migratory, though. If they can stay put and get enough food to survive, migration to a warmer climate is unnecessary.

We’ve been eating birds for millennia. They can be a bit hard to catch, sure, but the payoff is incredible: juicy thighs, fatty skin, delicious edible bones. And if you were to nab a big one like an ostrich or a wild turkey, that’s dinner for a week! Birds are definitely seasonal, though, and depending on where Grok was living, bird meat wasn’t always available. Does that mean poultry should only be eaten seasonally? Of course not. Meat is meat (well, dark meat is definitely not white meat, but it’s all meat).

What about the eggs? Egg laying is absolutely seasonal. Birds are wired to lay eggs in warmer weather, when food abounds. Even birds that stick around all year long aren’t constantly laying eggs. Grok undoubtedly loved eggs (he never had to deal with the egg yolk fear campaign), but he didn’t have steady access to them. Still, if eggs are just another form of meat, there shouldn’t be an issue with steady consumption of them… right?

Maybe, but there’s a bit more to the story.

Remember that health issues with food generally arise when we eat food that really doesn’t want to be eaten. Take grains, for example. Grains house the little plant embryos; in order to deter consumption and ensure growth, the grain employs lectins and other anti-nutrients. These are chemical self-defense mechanisms that can trigger auto-immune diseases and irritate the intestinal lining. Meat, on the other hand, comes with claws and teeth and legs (and sometimes poison) to dissuade consumption. Once the animal is dead, though, it’s dead. It no longer cares whether it’s eaten, so dead meat is pretty safe to eat. Just watch out for the ostrich’s legs when it’s alive.

What about eggs? Eggs are a different beast altogether – almost like a meat seed. A meat precursor. An egg has no active physical defenses (unless the mother’s around). It can’t sprout legs and run away. It does have the shell, which appears fragile but is actually incredibly resilient. Note the shape, which varies according to the nesting environment; cliff-nesting birds have the most conical eggs, ensuring a loose egg will roll around in a tight circle rather than roll off, while hole nesters produce more spherical eggs. Shells are meant to keep predators, faunal and microbial alike, away from the interior goods.

If you get past the shell, there’s another line of defense: the white. The egg white serves three purposes.

It stores protein for the growing organism – about 50% of the total egg protein.

It helps transport nutrients into the growing embryo.

It protects the egg from microbial attack.

That last one is where things get potentially hairy for us egg-loving hominids who only had historically seasonal access to them. Because the egg is a stationary, otherwise helpless bird “seed,” it has selected for toxic, antimicrobial proteins in the white to bolster defenses. In fact, other than ovalbumen, which accounts for 54% of an egg white’s protein content, the thirteen other proteins in a white are antimicrobial. They aren’t explicitly meant to hurt mammalian interiors, but what harms the microbes can hurt us, too.

Lysozyme is the most problematic egg protein, but in a strange, roundabout way. By itself, pure lysozyme is probably harmless. We even produce it in our own bodies. But because it has an alkaline isoelectric point, it can form strong bonds with other egg white proteins. It binds with the white’s other protease inhibiting proteins, like ovomucoid or ovoinhibitor, to avoid digestive breakdown by protease enzymes, and it can form hardy, potentially harmful protein compounds that pass through the intestinal lining and produce or exacerbate autoimmune or digestive issues.

Now, certain animals can adapt to chemical defenses, given enough time and exposure. Birds, for example, are wild seed-and-grain-eaters. They’ve adapted to the lectins given their steady exposure to them. Primal folks eat a lot of eggs. I’m one of them, and I probably eat them five days out of the week. But how long have we been eating eggs year-round? The first fowl domestication probably occurred 8,000 years ago in Thailand with the red junglefowl, but I imagine year-round egg production took a bit longer to perfect. Have we adapted to year-round egg consumption?

I’m not sure. Egg white allergy is relatively common, ranging from between 1.6-3.2% of the population. According to Cordain, it’s the second most common food allergy. That, plus the inherent purpose of the egg white itself, makes me suspect that there is something there. I don’t think year-round consumption of eggs is a problem for most people; I just think that certain individuals may be sensitive to the egg white protein, while others can down them without issues. I have heard of people developing egg allergies or negative reactions in adulthood, but that usually happens with people who eat a ton of eggs. I don’t hear about people developing lamb allergies.

Egg consumption doesn’t have to be seasonal, but our understanding of eggs is informed by the seasons. Seasonality merely limited historical access to eggs, which in turn limited our ability to develop universal adaptations to egg whites. That’s it. Frying up a scramble in the dead of winter may not be historically accurate, but who the hell cares? It’s not the timing of consumption that matters, but the frequency – and even that isn’t set in stone. If you love eggs, don’t stop eating them. They’re a fantastic source of fat, protein, and vitamins. If you have a preexisting autoimmune issue, though, filling up on eggs could make it worse. And if you start feeling like crap after every egg meal, you should probably ease up. Don’t make eggs your primary protein source (I’m talking five or six eggs each meal), and most of you should be fine. Just be aware that the ability to eat a dozen eggs every day is relatively novel, evolutionarily. I’m not saying that problems will always arise when we introduce dietary novelties, or even that they’ll be more likely to arise. I’m just saying that they may arise for some.

(I find it highly ironic that the only thing you really have to worry about is the egg white. Hmm, next time I’m at a diner I’ll try to order an egg yolk omelet. It might be even cheaper.)

By now, it’s clear that the seasons affect everything: organisms (sentient and inanimate) respond to changes in temperature, rainfall, weather, availability of sustenance by adapting, migrating, or dying; certain geologic features are molded by rain, wind, or glacier, while coastlines are obscured or revealed by changing sea levels. It’s not even so much that things are affected by seasonality so much as they are imbued with it. You know how space and time are forever linked and wholly dependent on one another? How the two are contextual and relative? Think of the seasons, life, and this planet the same way. It’s all linked.

Anyone have egg white allergies? Did you develop them recently, or have you always had them?

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. In yet another of the ways we are unique, your article points out how, rather than adapting to our environment (i.e. flying south in the winter) we force the environment to adapt to our needs.

    Greg wrote on April 5th, 2010
  2. wow that’s interesting i have never thought of eggs as seasonal, but obviously what you said makes sense…. however, i also plan to eat eggs year round. i HAVE TO admit that eggs in season from free range chickens at the farmer market are INCREDIBLY tasty. but they only come around once a year sadly

    MalPaz wrote on April 5th, 2010
    • If you constantly eat eggs without a break, it can cause allergies. In fact shellfish and eggs are very common allergens along with wheat and dairy.

      Kishore wrote on April 5th, 2010
  3. Excellent topic. I think it is really up to each individual to figure out which foods they tolerate well and which they need to avoid. I, myself, find that I tolerate both eggs and dairy (especially butter and fermented dairy) quite well, whereas I need to avoid the grains and legumes (except a bit of white rice now and then). If I had to give up my eggs, I think I’d cry.

    Aaron Blaisdell wrote on April 5th, 2010
    • I’d cry too if I had to give up eggs, and I’ve yet to falsify the ‘eat-eggs-liberally-year-round’ conjecture for me, though I haven’t tested seasonality rigorously.

      epistemocrat wrote on April 5th, 2010
    • i cried when i had to give up my dairy :(

      MalPaz wrote on April 5th, 2010
    • Yes, so would I! I buy organic free range eggs year round and enjoy them with my locally sourced back bacon (reared outdoors in the fields around here) :-) probably one of the best meals in the world!

      It’s interesting to really think about all these aspects though. Primal has certainly encouraged me to travel with my eyes even wider open than they were before.

      Kelda wrote on April 6th, 2010
  4. Love the article. I think I will stick to eating eggs year round. I don’t believe I am allergic to egg whites.

    I enjoyed a 4 egg omelet this morning with onion, mushroom, and coconut flakes – cooked with coconut oil. It was AMAZING!!

    I enjoy eggs 3-4 times a week which seems to be a good amount. Omelets and coconut pancakes are just very healthy and tasty. Why should I stop during the winter months?


    Todd wrote on April 5th, 2010
  5. I have sort of a built-in caution mechanism, and a love/hate thing regarding eggs. I think that’s a good thing because if I like a certain food too much, I eat it repeatedly.

    I can eat eggs for about 4-5 days in a row, after that I can’t look at them for a few days. I will not eat egg whites if I can help it. When I eat fried or boiled eggs, I give or throw away the whites. When I make an omelet, I add in a couple of extra egg yolks so I can make believe there are no white parts in there, lol. I don’t know why, but I have always hated eggs whites.

    This is an interesting post, reminding us once again to eat a variety of foods, and that sometimes we can be sensitive even to healthful foods like eggs.

    Suzan wrote on April 5th, 2010
    • @ Suzan, I sometimes wonder if an aversion to something specific is at least partially related to an underlying physical issue with that item.

      TexasPrimalSurfWahine wrote on April 5th, 2010
      • Perhaps. I think that when I did South Beach diet, I got really sick of eggs. Lately, I only like fried eggs, and eat only the yolks…

        Some people think that you crave what you are allergic to, which would make sense for me. (gluten, dairy)

        Suzan wrote on April 5th, 2010
  6. The WOTD today on today made me laugh:

    James wrote on April 5th, 2010
  7. I’m really enjoying the recent articles on seasonality. I never thought about eggs and seasonality before.

    I love that the primal way of living takes into consideration that everything is interconnected.

    Janet wrote on April 5th, 2010
  8. I have noticed and egg sensitivity recently, and it’s a shame because pasture raised eggs are probably the most economical good source of protein. I think I’ll try just eating the yolks for a while.

    Whew! I was thinking about giving them up entirely, now I may not have to. Thanks, Mark!

    Allbeef Patty wrote on April 5th, 2010
  9. How does an egg sensitivity manifest itself?

    Dave, RN wrote on April 5th, 2010
    • For me, they give me an upset stomach. I think now that my stomach isn’t upset all the time, I’m more sensitive to changes in how I feel.

      Allbeef Patty wrote on April 5th, 2010
      • I have the same reaction Patty, when I have eggs, unless they are pastured. When I get them straight off the farm, I don’t notice the upset tummy. Which is great since I love them so much! My it’s all in my head, who knows!

        Krys wrote on April 6th, 2010
  10. I’m glad this came up today, as I’ve been thinking about the seasonality of eggs lately. With my own chickens in the backyard, great organic free range eggs are in abundance and I’m eating them accordingly. But, in the fall, the availability will cease and I’ve been wondering if I should stop eating eggs until spring. I’ll have to think about this, as eggs are a big part of my diet, but I think going without is doable. At least, cutting way back as store bought eggs are not appealing any way.

    Sharonll wrote on April 5th, 2010
    • I agree on the store bought eggs. Do you have a farmers’ market in your area? Sometimes you can get good eggs at those.

      DianeThePurple wrote on April 5th, 2010
  11. I definitely think some people need to watch their egg consumption. When I started eating paleo I started having terrible GI trouble – in direct contrast to what everyone else was experiencing! It took me months to figure out that it was because I’d gone from eating 2-3 eggs a week to about 20. Since cutting right back down everything is hunky dory!

    PaleoMum wrote on April 5th, 2010
  12. This is probably WAY TMI but if I eat eggs too much, or too many days in a row, I get horrible egg farts 😛

    So I just have to be aware of that!

    Chandra wrote on April 5th, 2010
  13. No problem with eggs at all. I usually have two hardboiled eggs for lunch at work on weekdays.

    Unlike the previous poster, I’ve had no gas at all on the primal diet. My kids used to make fun of me for being gassy, but no more. Must have been all that fermenting grain and sugar.

    Tom wrote on April 5th, 2010
    • Apparently the whites are generally the problem, and the more cooked they are the more easily they are digested. So hard boiled would be better than, say, runny scrambled.

      PaleoMum wrote on April 5th, 2010
  14. I ate egg whites (no yolks) for years and developed an intolerance to them. I then switched to whole eggs and ate extra yolks and was fine. I did every now and then go for a week or two without eggs if I noticed any digestive symptoms from them. A short time away seemed to be enough to get rid of any allergy/intolerance.

    An interesting note, I dropped an egg accidentally on the floor once and my two cats were quick to come over and start licking it up. They ate the yolk paying careful attention to not eat the white.

    Kat wrote on April 5th, 2010
  15. Paleomum, I’ve had much the same experience. Which is quite sad, considering that eggs are the cheapest quality protein available, and tasty as well.

    Alex wrote on April 5th, 2010
    • Yeah… it’s just the whites that are the problem, though, generally. Haven’t tried a yolk-only scramble but it sounds good…

      PaleoMum wrote on April 5th, 2010
      • Try an egg-yolk and cream scramble. Yum!

        Suzan wrote on April 5th, 2010
  16. Some reptilian eggs are buried deep in a clutch and would sit an entire cold season before hatching…not that I have ever eaten Gator Eggs :) Gator meat yes…gator eggs…no :)

    mikecheliak wrote on April 5th, 2010
  17. Very interesting points about eggs. I hadn’t considered that they were only seasonally available to Grok. Too bad since they’re a cornerstone of my diet.

    But although I eat 3-8 fried eggs every day, they have never caused me any noticeable gastric distress. Perhaps it helps that I fry the whites crispy while keeping the yolks runny.

    Therefore, in the name of science, I will continue to eat an average of a half-dozen eggs daily, and report back with my statistically insignificant results in a couple of years.

    Timothy wrote on April 5th, 2010
  18. I would die without my eggs and kale every morning. Between my husband and I, we go through 2-3 dozen a week. Since we buy so much meat it helps us save a bit of $ to have an egg meal once a day, even buying the high quality ones at the farmer’s market are a good deal for the great protein. So happy we are allergy free:)

    BeeHollee wrote on April 5th, 2010
  19. Hmm.. I haven’t noticed any intolerance with eggs, but I certainly wouldn’t want anything to develop. I have been going through a dozen a day for almost 2 months now. I love my eggs!

    I am not certain what I would look for when looking for an intolerance. I feel fine after eating them. I always some other protein with them… usually some kind of meat.

    But if i were to scale my consumption of eggs down to say 6 with my breakfast only…. what would be a good replacement? Preferably cheap! Just more meat?

    Fox wrote on April 5th, 2010
  20. I’m a Wildlife and Conservation Biology major with a particular interest in ornithology (birds) and herpetology (reptiles/amphibians) so this post is really interesting to me. A lot of birds don’t really migrate and are opportunistic breeders and are likely to breed throughout the year when conditions are appropriate. I also wonder what the availability of reptile eggs (like turtles or larger varanid lizards) would have been like for Grok.
    It’s interesting how the shell and egg white are presented here. I’ve always been taught that the shell is primarily a good control for gas exchange and to prevent absorption of water and that the egg white acts as a sort of shock absorber for the developing embryo. It’s interesting to think about other evolutionary adaptations for those structures.

    Max wrote on April 5th, 2010
  21. Funny to hear that egg whites cause such problems with allergies. When I was a kid, I was allergic to egg yolks. Fortunately, I grew out of that one.

    Darrin wrote on April 5th, 2010
  22. I recently stopped eating eggs entirely and now just have meat/fish 2-3 times a day. I feel better since doing so. My sleep quality seems better and my digestion has improved. I may have always had a sensitivity but I didn’t really notice it until I cut them out. I am interested to read about other peoples experiences.

    Ry wrote on April 5th, 2010
  23. I eat them in a veggie omelet or soft-boiled (often with cheese and/or bacon/sausage and a bowl of fruit & yogurt) on the weekend and toss 1 or 2 raw ones into my (homemade) kefir/whey weekday breakfast drink 2-3 times a week. They seem to agree with me. I suspect dairy & I have a mild disagreement hence my transition to kefir which I believe may be the easiest to tolerate.

    Jay wrote on April 5th, 2010
  24. I believe I am allergic to eggs but I’ve never been tested for an egg allergy. I get a rash, sneezing, and a runny nose when I eat eggs. I suspect I have had the allergy since childhood. It was only when I ate lots of eggs on the Specific Carbohydrate Diet (SCD) that I figured it out. I’m also allergic to casein and intolerant of gluten (assumed to be celiac disease). I’ve had symptoms of a leaky gut for as long as I can remember, so none of this is surprising.

    Amy wrote on April 5th, 2010
  25. I was eating about 4-5 a day for 6 months….something inside of me made me take a break from them. What I have been doing recently is just going to the store and buying what pops in my head. One week I’ll eat nothing but vegetables….the next week I eat nothing but meat. I am able to read my body well….I listen and it tells me what I want to eat….some days….I just don’t eat, because I listen. Eggs are starting to sound good again and bacon always sounds good, so I guess I’ll wait and see what ends up in the fridge.

    Aaron Curl wrote on April 5th, 2010
  26. Eggs are best cooked by any method that cooks the white through and preserves the yolk in s state close to raw: fried overeasy, poached, soft boiled etc. But I’ve often eaten so many eggs in one sitting that the only convenient thing to do is scramble them altogether. Eggs are high quality, but I’ve gotten sick of eating them many many times. I always come back to the incredible edible egg though.

    fireandstone wrote on April 5th, 2010
  27. I generally eat 12 or more eggs every day (only 9 today). I cut them out for two weeks as a test to see if I had any issues. The only issue was… me really missing them! Funny thing is, when I was young, even the smell of cooking eggs would make me vomit. I use to go outside if they were being cooked for breakfast.

    I love raw eggs, but anymore I generally cook the whites, and do the yolks either raw or runny.

    Hard boiled I do have issues with. Al Gore would have a problem with me eating them if he knew. Do you sniff my drift? 😉

    Grok wrote on April 5th, 2010
  28. Hi Mark.
    Interesting read; I love the idea of sunshine with my berries (although I was found eating them in bed with some raw cream on the weekend)

    I wanted to ask you – what do you think about the idea of restricting eggs for a period of time when people have a lot of weight to lose? Given that they’re a higher-insulin protein than other meats …? I’ve found in many cases cutting eggs out causes a sudden drop in previously stubborn weight loss.

    Of course it could just be intolerance.

    Kat Eden wrote on April 5th, 2010
  29. Very interesting thoughts Mark. It’s great to learn about the natural and intended availability of food in a world where we can get what we want, when we want it!

    In fact my dad ate so many eggs when he was a poor student that he now cannot stand them. It seems his over consumption of egg (white) has made him mentally alergic, and I understand that he did start having physical allergic reactions (rash, swelling etc) when he used to eat them everyday.

    I love the nutrition and versatility of the beloved egg but like anything, in moderation!

    Luke M-Davies wrote on April 5th, 2010
  30. I just try not to depend too heavily on any one protein source. I’ll have all sorts of meats, tuna, eggs and maybe a little cheese throughout the week and that seems to work for me. Although, I would be interested to know whether cutting out eggs is a good idea if you’re going for fat loss.

    Nikki wrote on April 6th, 2010
  31. I’ve eaten four eggs a day for many years. I buy from a farmer at the farmer’s market. I fry them over lightly. I eat with Pakistani kabobs, ground organic walnuts, homemade applesauce, and berries. I’ve had no problems.

    Mammals have been eating eggs for at least 65 million years. That is how mammals were able to outlive the dinosaurs when the meteorite hit. This was a period of nutritional distress. The dinosaurs laid their eggs on the forest floor. They couldn’t eat and watch over them at the same time. Small mammals crept up and sucked out the contents. The only dinosaurs that survived were the small ones that could nest in a tree and sit on the eggs to protect them. Except on islands with no predators, you won’t find unprotected eggs on the ground.

    Don Wiss wrote on April 6th, 2010
  32. Egg seasonality is a concept that never occurred to me. I’ll definitely consider that when frost season arrives.
    I’ve recently started eating 8-12 eggs daily and, regardless of how prepared, don’t have a problem with them. I find cooking an inconvenient hassle so I mostly eat them raw, like Rocky. I break the yolks in my mouth and love the burst of flavor.
    Sorry if that sounds gross, but it’s become one of my favorite foods. Never had a case of food poisoning either. Thanks for the info.

    Marcus wrote on April 6th, 2010
    • I was thinking that Grok had to have eaten eggs this way. Sure he would have cooked them when he could but when he stumbled on a nest during one of his walks, he surely would have just consumed them right there.

      tokenn wrote on April 6th, 2010
      • @Marcus – I used to used raw eggs in my home made Bruce Lee style protein shakes and I blended the shells in too! Never a stomach complaint. I do have to say 8-12 per days seems rather excessive given the nutritional spec of eggs but if that’s what you like…

        Luke M-Davies wrote on April 6th, 2010
  33. Hey Marcus, just the other day and friend told me that if you eat raw eggs you don’t get the same nutritional value you would if you cook them.

    I wasn’t totally convinced and did a bit of research and found that most people have mixed opinions on this. Have you noticed a difference between raw and cooked eggs?

    Tyler wrote on April 6th, 2010
  34. I try to limit eggs to breakfast. I don’t generally eat eggs at lunch or dinner time so I should be good to go compared to the people around here who report eating up to 12 a day!

    Kevin @ My Primal Life wrote on April 6th, 2010
  35. Interesting….

    Have any of you heard about Jimmy Moore and his all egg diet he has just lost 24 pounds on recently?

    SharonW wrote on April 6th, 2010
    • Jimmy Moore is doing awesome on just eggs, butter and cheese. It’s working for him! I don’t think I could be that disciplined, I would miss my meat way too much!

      Krys wrote on April 6th, 2010
  36. I have IgG antibodies to egg white by a blood test and IgA antibodies by a stool test.

    I have never noticed a problem when I eat egg white, but that does not mean I am not reacting to them internally. I do have autoimmune diseases.

    Anne wrote on April 6th, 2010
  37. What about the fertilized/unfertilized issue? Would birds laying seasonally have only produced fertilized eggs, or do they produce eggs regardless, whether fertilized or not?
    Is there any difference between fertilized and unfertilized eggs?

    I actually tend to only eat eggs in the spring/summer when in season, as i dont go to the farm where i get my pastured eggs during the winter, and also i love goose eggs and they’re only available in season. I found a farmer who produce duck and turkey eggs too (in season) so when they start laying i’m defo looking forward to trying them!
    But at the farmers market the farmer said the turkeys need to mate first or something, which later got me thinking – so are the eggs fertilized or not? I wasn’t really sure what he meant, so i will ask next time. I’m pretty sure chickens don’;t have to be mated to produce eggs..

    reamz wrote on April 6th, 2010
    • The farmer I buy my eggs from has roosters. Some of the eggs are fertilized, most aren’t. The way you tell is the fertilized ones have a red spot in them.

      His hens lay eggs year round, though less in the colder months.

      Don Wiss wrote on April 6th, 2010
  38. my spouses’ egg intolerance results in a marked decrease in mood for 6-8 hours, but they don’t bother his stomach. He is intolerant to both yolks and egg whites.

    ATA member wrote on April 6th, 2010
  39. i love eggs, have marks famous omelets every morning

    Usman wrote on April 29th, 2010

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