Red meat has long been an anathema to the nutrition establishment. Not being privy to the thinking of the originators of the so-called heart-healthy diet, we assumed it was because of the association of meat with its burden of saturated fat and cholesterol, two food components condemned as promoters of heart disease.
Time passed and, despite considerable evidence that neither saturated fat nor cholesterol caused heart disease, red meat remained a pariah of protein foods. Several years ago, we learned that it was not just people opposed to eating animal products because of ethical or religious convictions. It also included a few highly respected biological scientists who recommended against eating red meat. They did not reject meat, only red meat aka muscle meat. With no reason given for why red meat was múscolo non grato, we decided it was just a matter of personal preference.
We learned recently from a lecture on nutrition that muscle meat has a much higher content of methionine than other parts of beef cattle, such as organ meats and structural parts. Further, methionine makes homocysteine. Miss Information enters the picture here; because everyone knows that homocysteine causes heart disease, methionine intake should be curtailed. Obviously, no more red meat! How could such perfectly good facts be so misinterpreted? What is the real story? What is methionine and why does methionine make homocysteine?
Methionine is an essential amino acid, which means it is essential for life and that human biochemistry cannot make it; therefore, it must be provided in the diet. Why is methionine essential? It is primarily because it is the sole provider of methyl groups (1-carbon units), which the body cannot make and needs in substantial quantity.
Methylation is an extremely important and always active reaction in human biochemistry. The methylation of DNA nucleotides makes possible proper functioning of cellular reproduction. It is also important in regulation of gene expression and is necessary for embryonic development. In addition to its roles in reproduction, methylation is required by such diverse functions as making many and varied kinds of proteins and protecting the body through its involvement in detoxification of heavy metals. There is no doubt that methionine is a valuable and irreplaceable nutrient.
Why does such an indispensable nutrient make such an undesirable biochemical as homocysteine? Examination of the methyl transfer cycle (see Figure below) shows that methionine has no choice. Methionine combines with the biochemical adenosine to make adenosyl methionine. This is the form of methionine that donates methyl groups. When the methyl group is removed, the adenosyl methionine becomes adenosyl homocysteine, which then sheds the adenosine group and becomes homocysteine. This is how methionine becomes homocysteine. It would make the same biochemical no matter what it was called.
Actually, homocysteine also plays a very important role in human biochemistry; it picks up methyl groups that have been removed in demethylation reactions and recycles them back to methionine.
The Methyl Transfer Cycle
What does homocysteine do that makes it such a bad actor? Actually, it does not do anything untoward, unless it is prevented from doing its job. What is its job? Its job is either closing the methyl transfer cycle by picking up a methyl group and returning to methionine or being converted to the sulfur amino acid cysteine. What prevents homocysteine from doing its job? It is a deficiency of B vitamins, namely vitamin B6, vitamin B12, and folic acid. When deprived of these vitamins, homocysteine will accumulate to excessive levels and ultimately cause inflammation and proinflammatory eicosanoids. Otherwise, in people who eat a healthful diet, homocysteine is just one of thousands of harmless products of metabolism.
If there is a lesson to be learned from this narrative, it is that it is unwise to discuss newly found facts without first investigating their significance for human health and well being. Of greater importance than a lesson to be learned is the damage Miss Information does to scientific truth in the nutritional information imparted to the public. Miss Information has enlisted people whose nutritional advice is trusted and who should know better to support the unjustified and harmful recommendation to eliminate red meat from the diet. The question is why?
Perhaps then it’s a double whammy for those put off both meat and eggs; eggs being the major source of choline – with 3 methyl groups. Perhaps americans in particular are getting some choline from soy, which seems to be creeping into New Zealands processed food. However swapping choline sufficiency for the antinutrients in soy (especially the goitrogens) wouldn’t be that helpful to ones overall health
You are so right, Lew, many people are suffering as a result of renouncing foods that clinical experience, backed by solid nutritional science, says are beneficial. We believe it is because people are confused about what and whom to believe. Hopefully, truth will eventually prevail.
Your point about choline is an excellent one. The major and almost exclusive dietary source of choline (phosphatidyl choline) is found in the phospholipids fraction of the fat in meat and egg yolks. So we can add those who avoid animal fat to meat and egg avoiders as people deficient in choline. The only supplement that we know of that supplies choline is lecithin (which we add to soups and stews to emulsify the fat layer rather than skimming it off the top. [We also eat meat and eggs] ).
Lecithin is a mixture of phospholipids isolated from egg yolks, whey, or soybeans with the latter being most common. Fortunately, soy lecithin is a waxy material that contains none of the water soluble components of soy. As you indicate, the contraindications against any other dietary use of soy are too many to discuss here.
Our best wishes to you and your beautiful country.
I’d be inerested to hear your opinion on another question that I’m curious about and that is whether grain fed beef in the USA and Europe is so full of polyunsaturated fatty acids that perhaps it should be avoided!
This is an important subject, Lew, but not one we can shed much light on. We know that grain-fed beef have a much more varied diet than grass-fed animals, which has an effect on many qualities of the fat and flesh. We have read that the omega-6 content of the fat is about the same independent of diet, but we do not know. We do know that the omega-3 content of fat is much higher in grass-fed animals. We are fortunate in living in a rural community where we have an excellent source of meat from grass-feed animals. No matter which, beef is a good food.
As a rule, omega-6 fats are plant fats and omega-3 are animal fats, but a confounding fact is that animals reflect what they eat. So animals fed on soy will have more omega-6 than normal. This appears to be a problem with poultry. The fat of chickens fed soy is very high in linoleic acid (omega-6).
Hope this helps.
Thankyou, I do know that at least some Australian cattle is fed grain for a few months prior to slaughter. I also know that our cats refuse to eat it – perhaps they know more than we do! Our food safety Minister has jsut approved the growing of GMO soy; we just love copying other peoples mistakes!
I agree. We need more of this information and not the opposite.
It is really strange that some would want us believe that red meat is dangerous. There is politics and money in everything
Thank you very much for your comment, Elisabeth.
It is so sad, but true that you are right. Hearing from people who have the wisdom to see beyond very persuasive nutrition propaganda bodes well for a healthful future.
And as the B complex are depleted due to carbohydrate consumption maybe the advice should be to cut the bread and just eat the meat filling.
Thank you, Mark, for a delightful chuckle. Every once in while, we enjoy a good hamburger (without the mayo and other goo). We follow your advice and remove the top half of the bun and use the bottom half as a carrier. The birds flock to our car when they see us coming.
Perhaps your wise suggestion will inspire a new eating style.
Good point but to go back to your intro, the short stories of Isaac Bashevis Singer equating meat eating with other sins to appreciate the mind set of the vegetarian and the disgust at eating animals. I do not share that mind set but it is good to know there is something real underlying the phony science that it gives rise to.
Thanks, Alice & Fred,…This post made homocysteine much more clear for me!
I’m researching homocysteine because I just had a full blood panel done, and everything looks great except for 2 markers: (1) homocysteine @ 15.8 umol/L (normal range: 0.0-7.2 umol/L) and (2) alanine aminotransferase (aka: ALT / SGPT) @ 38 IU/L (normal range: 6-29 IU/L). I eat a very strict LCHF high-quality diet, supplement only with virgin coconut oil, fermented cod liver oil, high-vit. butter oil, desiccated calf liver, wild salmon roe, and raw egg pastured egg yolks (2 per day). I eat wild/grass-fed meats with lots of whole-fat dairy (butter, cream, etc.), and steer clear of soy, sugar, starch, and grains. Any advice on why my homocysteine would be that high? And any ideas on how to reduce? I haven’t had a B vit. panel, but don’t suspect B deficiency with all the liver, wild salmon, and grass-fed beef I eat. Thank you in advance!
Sounds a though you have a very healthful diet, Jenny. About your homocysteine level, have you spoken to your doctor about it? Our first thought would be to check your intake of B vitamins (B6, B12, folic acid).
These B vitamins serve as coenzymes and are essentially nontoxic. Because of biochemical individuality, some people require more of some B vitamins than the average. We are not physicians, so we do not recommend B-vitamin intakes for individuals. However, Kilmer McCully’s book The Homocysteine Revolution, Paperback, February 1, 1999, contains a wealth of information including B-vitamin dosages. We think you would find Dr. McCully’s book very instructive.
Best wishes to you for your continued good health
Thanks, Alice & Fred…Unfortunately, I live in an area where LCHF-friendly clinicians don’t exist. I’m always searching for one, but the closest is a GP who recommends LC, but cautions against HF (ergo, high protein). So, my MD’s opinion is pretty useless.
I just read the Amazon “free preview” and ordered the book you recommended to add to my understanding of the biochemistry. I’ll get my b-vite values tested to get a baseline and treat with diet from there.
Since I’m eating such a b-vite rich diet already, would you recommend I look into any intestinal issues that may affect absorption? If so, where would I even begin? Thank you!!
Unfortunately, Jenny, you are in a fairly common situation – lack of healthcare providers who understand low-carbohydrate nutrition. Since you had a blood test for homocysteine, we assumed the physician who ordered the test would be able to interpret the results.
Your next step is to read Dr. McCully’s book to learn about what conditions make for high homocysteine values and then either remedy the cause or follow the recommended dosages suggested for your homocysteine value.
Another possibility is that the laboratory results were wrong. In the light of all “normals” in your blood panel (alanine aminotransferase – not too high to be meaningful without a lot of other “abnormals.”), it might be an error. You might want a retest.
Until you do a lot more thinking about your problem (e.g. reading Dr McCully) and trying supplementation with the B vitamins (the levels in your body are more important than what is assumed to be in your diet), it is too early to think about more tests.
About intestinal issues, we do not know where to go other than your health care provider. We are sorry we have no more help for you.
Good luck with your studies. We hope they bring you answers.
Hi Alice & Fred,
Just wanted to post a quick update about our exchange that’s providing more questions than answers. I asked my MD to re-test my homocysteine as well as test B12 and B9 (I asked for B6 as well, but it got left off the lab order form), and just got the results back today. The new homocysteine value is at 10.4 umol/L. Still high, since normal range (from this lab) is 0 – 10.3, but a substantial 34% lower than my value of 15.8 last month. I have yet to read anything about such a drastic change in only a month (with no dietary/lifestyle changes), so if you have any ideas, I would greatly appreciate them. =)
I’m very happy with my B9 at 19.9 ng/mL (normal range: 5.5 – 24.0). My B12 came back “normal” at 501 pg/mL (range: 200-1100) but I will be working on getting that up by adding some mollusks to my menu every few days. I didn’t take a baseline of either of these markers before switching my diet years ago, so nothing with which to compare.
Once again, many thanks!
Whatever you are doing, Jenny, must be the right thing. How does one explain a 1/3rd improvement in an abnormal value such as you have seen in your homocysteine number in just one month? Was the result from a different lab? Your results may just reflect a more competent lab. You say your new value is 10.4 and the lab normal value is up to 10.3. What does your health care provider say? He/she is the only one who has all the medical information necessary to evaluate the data.
I’m not sure where you’re getting your info, but good topic.
I needs to spend some time learning much more or understanding more.
Thanks for excellent information I was looking for this info for
my mission.
We are pleased that you liked the post. We would sure like to help you, but we do not know what information you need.
All of the information in this post can be found in a college biochemistry textbook. Do you know what proteins, carbohydrates, and fats are? How about amino acids? Let us know what information you are interested in and we will try to point you to some basic books
i too got a high homocysteine number when tested three weeks into keto. It was 13.9. I am confused and need advice to what to be concerned about and how to proceed. My B’s were not tested. I can not afford any more testing at this time. What to do?
Hi Kristy. First we would ask if you are under a doctor’s care and do you have symptoms related to high blood homocysteine. If you are under care, your doctor would be the best person to ask. If you do not have a doctor to ask, we suggest you get a copy of Dr. Kilmer McCully’s book The Heart Revolution, (http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Dstripbooks&field-keywords=Kilmer+McCully).
The Heart Revolution answers just about every question asked about homocysteine, including how much to take of B6, B12, and folic acid for the various blood levels of homocysteine. If you are unable to buy the book, ask your library to get a copy for you. Also, read Jenny’s comments and responses above. They might be of help to you.
There are supplements on the market that contain a combination of B6, B12, and folic acid. They are called homocysteine regulators. Check with your pharmacist or health food store for information about these products. They are not expensive. They could solve your problem if your homocysteine level is due to a deficiency. They are not harmful if you take them but do not have a deficiency.
Meanwhile, Kristy, stay firm with your keto diet – it is the key (good pun) to good health and self healing. Your keto diet alone might solve your homocysteine problem.
Let us know if you have more questions. We hope the above is helpful
Thank you for explaining how methionine and homocysteine metabolism work when all the necessary nutrients are present for the body to do it’s job properly.