Butter and Eggs: What They Share

To many dieticians and much of the general public, the similarity between butter and eggs is that both are bad for you. Butter: Fattening! Clogs arteries! Eggs: High in cholesterol! To me, it’s the opposite: both seem to be unusually good for us. Butter seems to make my brain work better and may have reduced my risk of heart attack. Eggs — at least, scrambled eggs — are especially well-liked by Mr. T, a rat. There are many similarities between rats and humans. Humans also like eggs. The foods we like are a guide (imperfect) to what foods are good for us.

Here’s another similarity between butter and eggs: Both must be complete — contain all necessary nutrients — much more than any other food. Butter is large part of milk. When mammalian offspring are very young, mother’s milk is their only food. Eggs, of course, must contain everything needed to become a baby chick (as a commenter named Rashad pointed out). No other foods — not fruits, not vegetables, not whatever other foods your great grandmother or other ancestors ate — have been under this sort of evolutionary pressure.

The evolution of lactose tolerance and my butter discoveries.




24 Responses to “Butter and Eggs: What They Share”

  1. Ezer Says:

    Scrambled eggs with butter and cheese: superfood? I love it!

  2. Elizabeth Molin Says:

    Seth, can you give me the source for the info you posted previously on Dr. Clara Davis? Thanks.

  3. Seth Roberts Says:

    Elizabeth, my post contained a link to my source. Here is another link:


    if you want more sources. search “clara davis diet self-selection”.

  4. Ezer Says:

    I think the preference for the food is a guide to the importance of that food only in a sort of “environment of evolutionary adaptedness”, in terms of the constraints under which humans evolved. For example, our taste for sweet evolved in an environment with scarcity of fruits and where the benefits of additional calories and vitamin C outweighed the harm of the fructose.

  5. Seth Roberts Says:

    I think the preference for the food is a guide to the importance of that food only in a sort of “environment of evolutionary adaptedness” (EEA)

    “only in” is too strong. Lab experiments — that is, not in an EEA — show that rats can choose a healthy diet, as I described in my original Mr. T post. I agree that away from an EEA the interpretation of food preferences — what they tell us about how to be healthy — isn’t simple. But they still tell us something.

  6. Ezer Says:

    In our actual environment, this taste for sweet is maladaptive, because there isn’t restriction on the fructose available anymore.

  7. SB Says:

    What they share is my plate!!

  8. Jeff Says:

    Seth –

    Just curious if you have ever determined an optimal dose for fermented food as you have with Flaxseed oil? I consume about 1/2 a cup of home fermented kefir including the cottage cheese like substance in my taste free smoothie daily.


  9. Ezer Says:

    I agree with you, an innate preference could be indicate something worthy of investigating, especially in consideration of an probable EEA.

    OT: How can I italicize text in a comment?

    [i]test of italic[/i]

  10. Alex Chernavsky Says:

    @Ezer: Instead of the square brackets, use the less-than and greater-than signs.

  11. UncleLongHair Says:

    Incuding the eating preferences of a single domesticated rat is pretty weak evidence.

  12. Aaron Blaisdell Says:
  13. Aaron Blaisdell Says:

    I tried “” suggested by Alex, but it didn’t seem to work.

    Btw, I love butter. I try to eat a tablespoon of grass-fed raw milk derived butter each morning along with my high-vitamin fermented cod liver oil.

  14. Aaron Blaisdell Says:

    Yikes. In the “” in the above comment, I typed the less than sign followed by “test in italics” followed by the greater than sign. It seems to result in the text being entirely omitted from the comment. Would be nice to know how to create an italicized comment, though.

  15. Tom Says:

    Aaron, it’s a pretty standard markup. Hopefully the symbols will come through if I put in additional spaces:

    [Obviously, remove the extra spaces before and after the angle-brackets (shift-comma and shift-period) when you use them]:

    Start italics:
    End italics:

    Start bolding:
    End bolding:

  16. Tom Says:

    Dang, it accepted them even with the spaces.

    Anyway, before the section you want to italicize, enter a shift-comma, then a lowercase i, then a shift-period.

    To stop italicizing, enter a shift-comma, then a forward-slash (unshifted questionmark), then a lowercase i, then a shift-period.

    (You can bold by replacing the lowercase i with a lowercase b.)

  17. Sara Says:

    I am thinking about what might cause the effects you see with high butter consumption. As your diet was low fat, do you think you are experiencing the benefits of fat-soluble vitamins? (D, K and A specifically are quite high in butter, particularly Vit A, retinol form). If you analyse your diet as it was, perhaps you were low in these vitamins? The question of Vitamin D is interesting because eggs also contain it, but apart from fish, there are hardly any other dietary sources (milk, eggs, fish and some mushrooms, I think that’s it for vitamin D). Do you think you might have been in a state of vitamin D deficiency perhaps and have rectified it with the butter and egg consumption?

  18. Seth Roberts Says:

    As your diet was low fat,

    It was not low-fat. It was very high fat. Before I started eating lots of butter, I ate lots of pork fat (for the sleep benefits).

  19. dearieme Says:

    What are the dietary benefits of blood? I’m thinking of “black pudding” and other “blood sausages”.

  20. Sara Says:

    Oops, I misread the link as ‘low fat, high cho’. Sorry. I’m new to the blog but did a bit of reading. It seems you were already taking vitamin D3 as well. Maybe it’s not related to micronutrients at all but the effect is very interesting, for sure. I’ve got to say, I would like to try the butter experiment but the amount of calories in that much butter scares me. I might get a fat butt, and that would give me anxiety.

  21. Elizabeth Molin Says:

    Thanks again, Seth (did I say that I’m a very bad researcher?).

  22. et Says:

    Why stop with cow’s milk? Is milk from any mammal good for you?

  23. dearieme Says:

    “Is milk from any mammal good for you?” Milk from goats and ewes is certainly good for cheese.

  24. Nick Says:

    I agree with the milk and egg theory but I think it also comes down to the phenotype, life stage and life style of the person. I see these foods as anabolic overall, and if your system still contains anabolic capacity than it could be good for you, however if you do not have this anabolic capacity left than it can be deteramental. Staying on the edge of and measuring your Homeostasis is hard but swinging up and down between anabolism and catabolism on average would put you on that edge.