Some people seem to have trouble with pork. The most common symptoms are fatigue, inflammation, and – most interestingly – high blood sugar in both diabetics and non-diabetics. When I eat fresh pork, my blood sugar increases to between 120-150 and stays there for a very long time, and I am not diabetic. When I eat lamb, however, my blood sugar levels are between 96-113. For more detail please read my post Lamb is My New Best Friend.

Several Type 2 diabetics in the group Principia Carnivora, have reported blood sugars numbers as high as 175 after eating fresh pork and high fasting blood sugars the day after eating it. Aged pork products like bacon and prosciutto, however, do not seem to have the same effect. An interesting study by the Weston A. Price Foundation may shed some light on this conundrum.

The Weston A. Price Foundation (WAPF) is very knowledgeable about how different foods have been prepared by non-industrialized cultures. Pork is traditionally prepared by aging in salt or marinating in vinegar prior to cooking and consuming. So, WAPF decided to do a very small study examining how pork prepared in different ways affected the blood of three volunteers. Here is a description of the study:

“Three adults, including two females aged thirty-seven and sixty, and one male aged fifty two, participated in the study… Subjects each came to the laboratory once weekly for five weeks at the same time of day by individual appointment. On the days in which they participated, subjects were required to fast for at least five hours. A baseline blood test was first done. Each subject was then given a measured amount of meat to consume, at least three ounces.

All of the meats used were of the highest quality from sustainable small farms raising pastured livestock. Five preparations of meat were used:

1. Unmarinated pastured center-cut pork chop;

2. Apple cider vinegar-marinated (twenty-four hours while refrigerated) pastured center-cut pork chop;

3. Uncured pastured prosciutto;

4. Uncured pastured bacon;

5. Unmarinated pastured lamb chop.

The meats (1), (2) and (5) were cooked over low heat in a cast iron skillet for up to one hour, with a little water but no added fat, and salted to taste. The cooked meats were prepared well done. The bacon was cooked until slightly stiff, but not crisp or dry. The prosciutto was consumed from the package without any preparation.

After consuming the pork, subjects were allowed to leave the laboratory, instructed to drink only water as needed, and to refrain from eating anything else. Five hours later, each subject returned to the laboratory for a post-meat blood test.”

The results were fascinating.

“The results show unequivocally that consuming unmarinated, cooked pork shows a significant negative effect on the blood. Five hours after consumption, subjects showed extremely coagulated blood, with extensive red blood cell (RBC) rouleaux (cells in the formation of stacked coins), RBC aggregates, and the presence of clotting factors, especially fibrin…Two of the three subjects felt fatigued after eating the pork chop, which suggests reduced peripheral blood circulation due to RBC stickiness and aggregation. Because the tiniest microcapillaries are smaller than the diameter of a single blood cell, each cell must pass through singly and deform its shape in order to do so; blood cell aggregates simply cannot pass through them. ”

“By contrast, all three subjects reported no fatigue or other symptoms after eating the marinated cooked pork chop… [One] subject’s blood looks completely normal before consuming this pork chop. Then, five hours after consuming the same size portion of a marinated pork chop… The RBCs in this [subject’s] blood sample show a very slight stickiness or tendency to aggregate, and a few platelet aggregate forms are seen, with no fibrin. The subject’s blood is largely unchanged from before. The other two subjects showed essentially no change before or after consumption of the marinated cooked pork.”

“[in] the blood of the female subject, age thirty-seven, fasted, prior to consuming four strips of uncured pastured bacon… [her] blood [was] normal and healthy, without any RBC aggregates or fibrin… [Then] five hours after consuming the bacon… [her] RBCs [were] not aggregated; there [was] only a minuscule amount of platelet aggregates and fibrin. [Her] blood is essentially unchanged over baseline. The other two subjects’ blood samples also appear about the same, before and after consumption of bacon, too.”

“[Similarly], the blood of a subject, male, fifty-two, prior to consumption of prosciutto… look[ed] normal and healthy… [And] the blood of the same subject about five hours after consuming three ounces of pastured prosciutto… look[ed] normal and healthy… Moreover, the blood of the other two subjects also did not change significantly pre-post eating [of the] prosciutto.”

“As an additional control, we also looked for an effect from consuming an unmarinated, pastured lamb chop on the blood of the same three subjects. The blood of the female subject, age thirty-seven, prior to eating the lamb chop… [was]… normal, healthy blood with a few platelet aggregates. About five hours after consuming the lamb chop, her blood appear[ed]… about the same as the pre-lamb condition. Moreover, the blood of the other two subjects did not show any significant changes after consuming lamb either.”


1. Consuming unmarinated, cooked pastured pork produces blood coagulation and clotting in blood examined at five hours after eating; however, consuming marinated, cooked pork does not produce any blood coagulation or clotting.

2. Consuming processed forms of pastured uncured pork, including bacon and prosciutto, does not produce any blood coagulation or other visible changes in the blood at five hours after eating.

3. Consuming unmarinated, cooked pastured lamb does not produce any blood coagulation or other visible changes in the blood at five hours after eating.

“The results suggest that unmarinated cooked pastured pork may be unique in producing these coagulation effects on the blood, which also appeared quite rapidly, in less than ten minutes after blood draw, and did not clear up during an hour of observing the blood under the microscope.”

“The early blood coagulation and clotting observed after consuming cooked, unmarinated pork are adverse changes in the blood. A shorter blood coagulation time is associated with increased systemic biochemical inflammation as well as the possible formation of blood clots in the body, as in heart attack or stroke. This condition in the blood, if chronic, is associated with increased risk of chronic degenerative disease, including cardiovascular disease, cancer, autoimmune disorders and others.”

“We speculate that raw pork contains a toxin, unidentified to date, and that heat alone from cooking cannot destroy it, but that fermentation with salt, and also acid plus heat, do so. This toxin in pork, if it exists, is therefore heat-stable and requires further denaturation by salt or acid in order to detoxify it.”

For more details, please see their article: How Does Pork Prepared in Various Ways Affect the Blood?

Although WAPF, does not have any idea what the “toxin” in unmarinated or unaged pork might be, Dr. Peter D’Adamo’s work into how food lectins affect different blood types might offer an intriguing possibility. Apparently, pork contains a lectin that will glom all blood types in vitro. In other words, if a drop of this lectin is injected into your blood stream, your blood will agglutinate and you will die. The premise of D’Adamo’s dietary recommendations is that we should avoid foods that contain lectins that are known to agglutinate our particular blood type.

D’Adamo found in his practice that if people avoid foods containing the lectins that will agglutinate their blood, their health will often improve. It is certainly possible that people could absorb some of these food lectins intact and that this could negatively affect their blood quality – not to the point of actually killing them as would injecting the lectins directly into their blood stream, but enough to overtax their immune system and cause them to become ill with any number of chronic or autoimmune illnesses.

Apparently pork has a lectin that agglutinates blood types O and B, as well as an antibody to blood type A. He explains,

“Hog is very “A-like” immunologically, which makes it an avoid if you happen to have antibodies to the blood type A antigen, like type B’s and O’s do. Paradoxically enough, hog also has an antibody (iso-hemmaglutinin) in its tissues which reacts to the A antigen, so it should be avoided for this reason by A’s and AB’s as well.” (From: Why All Blood Types Should Avoid Pork)

It is possible that when pork is marinated in vinegar or aged in salt, the lectin and/or antibody is somehow broken down or altered in such a way that it is no longer capable of agglutinating the blood. It is – of course – pure speculation on my part, but the most plausible idea I have come across so far.  D’Adamo classes bacon and fresh pork together, but I have no way of determining if the lectin was actually found in both types of pork products, or if he is just assuming it is in bacon because it is in fresh pork.

It is also interesting to note that Dr. H. L. Newbold – who prescribed an All-Meat diet in his medical practice – found that most of his patients reacted very poorly to pork. He only had a handful of patients who felt good after eating pork, and – in a strange twist of irony – one of these patients was Jewish! The meat that Dr. Newbold found to be the most universally beneficial was beef.

Similarly, Dr. J. H. Salisbury, a prominent physician in the mid-1800s – who developed what became known as the Salisbury Cure – found that pork was a sub-optimal meat. Dr. Salisbury was a pioneer in using food to heal disease. He developed his diet by living on one food at a time for days, weeks, or months. He tested foods in this way to see how they affected his body. After many years of experimentation, he came to the conclusion that beef was the best food for mankind. Runner-up was lamb. A variety of other meats were considered okay if beef and lamb were unavailable, but he specifically discouraged his patients from eating pork.

So, if you are trying a Zero Carb diet and feeling tired, inflamed, or experiencing higher than average blood sugars, you may want to consider removing pork from your diet for a while and see if you feel better without it.

20 thoughts on “Pork

  1. Thank you Esmée! This article is exactly what we needed at the perfect time too. It always seems that when we come up with a problem doing Zero Carb, you have already have discovered the answer. Thanks again!


  2. Pingback: Lamb is My New Best Friend | Eat Meat. Drink Water.

  3. I’m really concerned about a two things, 1. You say you’re not diabetic but the blood glucose readings you cite are really high, what are your fasting numbers? 2. The number of people in the Weston Price study is so few that the results are absolutely meaningless. Is there any real science that supports pork as an issue?


    • Bill – I don’t know of any study that has been done on a significant group of people to see how pork affects them. I was just trying to figure out why Myself and several others might be experiencing these higher blood sugar numbers after eating pork. The mini-WAPF study and Dr. D’Adamo’s lectin and antibody info are the only things I could find that might explain it. I also find it extremely interesting that both Dr. Salisbury and Dr. Newbold found pork to be less than optimal for their patients. I am simply sharing my journey. When I eat pork, my fasting numbers are above 120 and can go as high as 150. When I eat lamb, my fasting numbers are below 110 which is fine on a low-to-no carb diet. Your response to pork may be completely different than mine. And remember,this is fresh pork I am talking about, I do not eat marinated or aged meats. A member of Principia Carnivora who is a Type 2 diabetic get high blood sugar on from fresh pork, not bacon and the like. The only way to tell if this is true for you is to test yourself.


  4. excellent and useful summary of a very little known subject.
    I feelthat your “speculations” are spot on. I have the same elevated FBG when I eat either pork or too much protein at night. if i stop both factors,, it drops below 100 in two days. .


  5. Consuming unmarinated, cooked pastured pork produces blood coagulation and clotting in blood examined at five hours after eating; however, consuming marinated, cooked pork does not produce any blood coagulation or clotting.

    Taking a cue from the pic at the top of this post, may i be so bold to suggest a Vitamin K component? If the pigs are eating lots of grass (as in the pic), then the Vitamin K they are getting from the grass is getting stored in their meat…and then WE come along to consume it, and guess what? Possible Vitamin K overdose!

    But then, I;m just a lowly housewife who never finished college…

    Also, I recently learned about the effects of vinegar on blood sugar through Dr. Jason Fung’s website–vinegar and dill both work to LOWER blood sugar, both independently and together. So diabetics, listen up–marinate your pork in vinegar before cooking, and have a dill pickle with your pork!! Hubby and I have been going through dill pickles like you wouldn’t believe, because they’re cheaper than insulin, and THEY WORK. Even the juice by itself works.


    • The pork that I ate was not grass-fed, and it is possible that grass-fed or pasture-raised pork would not raise blood sugar like the commercial stuff does for me.

      The dill pickle thing is fascinating! Thank you for sharing.


      • Why not combine the two? Start marinating your pork in dill pickle juice. I’m going to give it a try, even though pastured pork is the only meat that doesn’t send us soaring–the higher the fat content, the better we do. Hubby hates the taste of lamb, otherwise it would be our best friend too. I sneak it into meatloaves and stuff by mixing it with sausage or chorizo.


          • My meaty friend–I just got back from an appointment with my rheumatologist, who started to give me the rundown about arthritis and gluten (with which I was already familiar), and that got me thinking about your case. Gluten is the short way of saying agglutination, and gluten comes from grains. By any chance, do you know if the test subjects were fed grain-fed meats? If so, the grain feeding would explain the blood agglutination…I think (coming from an arthritis angle). Cross-contamination of offending proteins often happens when you have manufacturing plants processing more than one kind of food without cleaning the machinery between runs (example: grains and dry beans–if you look closely enough on the packaging, you’ll find a message that says “processed in a facility that also handles like soy, corn, or dairy.

            The doc I saw today (not my normal doc) was duly impressed with my knowledge about arthritis and food, how nutrition affects everything in our bodies, and was surprised to see a spry-looking, apparently mostly healthy 53-year-old (who has no need of hair dye…YET). They asked me how long I had the arthritis, and I said, “since I was three.” No pain, very low CRP, no crutches or other medical devices needed for walking. They asked me what meds I was taking (referring to biologics), and I said none to date. Yeah, I got joint damage, and one day I’m gonna need a new shoulder and maybe some new knees, possibly a new right hip, but they don’t bother me now.


          • I strongly suspect the meat used in the study was grain fed. I certaily know people who react to meat fed grains, but I have celiac and I do not. However, pork itself has a lectin in its tissue that is also an agglutinin, and I believe this is why I personally react to pork. Red meat has no lectins and I think this is why most people seem to feel best on beef and lamb.


    • Why wouldn’t we get this response to beef then? Cows eat a heck of a lot more grass than pigs do.

      (I can guess one possibility–maybe cows convert more K1 to K2 than pigs do? K2 isn’t a clotting vitamin as far as I can tell.)


  6. I’d like to know more about this dill pickle thing. I know on ZC we are supposed to only eat from the animal kingdom but am still interested in this theory. I am in the UK and I *think* our dill pickles are in a juice with sugar in the jar? Is it the same in other countries?


    • In the US, we have sweet pickles and sour pickles (no sugar). But either way, pickles are not zero carb because they come from the plant kingdom. Zero carb is not so much about no carbs in the diet as it is about no plants in the diet.


  7. I eat fresh pork all the times. I put just a little but rub seasoning on it, put it in the oven and done. I like it better than beef for its tenderness. Never had any tireness or bloating or anything like that eating pork fresh from pig. Am I just different?


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