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Conventional beef vs grassfed beef
Quote from Retinoicon on May 26, 2021, 6:32 pm
Quote from salt on May 26, 2021, 5:59 pmAll of these studies have quite different numbers but they all show the same relative values, that grass fed has way more VA than grainfed and I think that is the most important take away. I think probably the numbers on the first page of this page are more realistic. I think they use different methods of measuring it, how long has it been degraded, how has it been stored etc. are all factors. Most of the papers I've seen seem to suggest that 100g of beef has about 5-10 mcg per 100g, and grassfed probably has 5x to 10x that amount.
With respect, the numbers on the first page seem to be about beta carotene, not retinol. Beef is an animal food and the retinol content is far more important to folks like us than the beta carotene content, which is minimal compared to retinol. I am quite worried right now. I emailed one of the others of the Egyptian/Japanese study that measured retinol. Thanks for posting these studies, anyway.
I'm sorry, maybe I've got my numbers all mixed up and confused. I have bad brainfog now due to a diet experiment with carnivorous keto. Anyways at least some studies have much lower measurements.
This study https://www.sciencedirect.com/science/article/abs/pii/0889157588900221 is available via sci-hub. Their measurements for 3.4% fat ground beef was 4 mcg of all-trans-retinol per 100g. But maybe they just measured retinol, and the other also measured retinal and retinoic acid. I don't know. To be honest I'm too brain fogged to figure this out for now.
Anyways, if you get a reply from the researchers please post it on this forum.
That Finnish study does have quite different numbers from the Chinese and Egyptian/Japanese studies. Yeah, I don't know what all-trans-retinol means. Interestingly, the beef all-trans-retinol values are almost exactly proportional to the fat content. Brisket has five times the fat content of the boneless shoulder blade and five times the value for the all-trans-retinol!
The Finnish study is from 1984 and it is possible measurement improved between then and the newer Chinese and Egyptian/Japanese studies.
Here is a US study on vitamin A supplemention of grain finished cattle. For the group not getting the supplements, the retinol level in subcutaneous fat, not lean muscle, is 0.8 mcg/g. The type of corn also affects the retinol level.
Sorry everyone for all the posts. Here is some good news about grain fed beef. It doesn't answer the question about retinol levels in either grass fed or grain fed beef, but it does state that vitamin A supplemention is BAD for the commercial interests of beef producers, as vitamin A or beta carotene makes the animals LEANER (for intramuscular fat/marbling) and producers get more money for FATTER animals. Of course this seems contradictory to @ggenereux2014's experience that a low vitamin A diet made him lose body fat.
Quoting: "Restricting vitamin A intake increases IMF deposition. Vitamin A (also known as retinol) inhibits adipocyte differentiation [128]. The activity of glycerol-3-phosphate dehydrogenase, a biomarker for adipogenesis, decreases in bovine preadipocytes cultured with retinol [129]. A negative correlation was observed between serum retinol concentrations and carcass MS values in Japanese Black cattle [130,131]. Several studies have shown that restricting vitamin A in the diet, or low beta-carotene (a precursor of vitamin A) intake, increases body fat, including IMF, deposition. A study of Angus-crossbred steers showed that animals not supplemented with vitamin A had higher MS and QG compared to vitamin A-supplemented animals [132]. The same authors reported that exclusion of a vitamin A supplement induced hyperplasia in IMF, but not in the subcutaneous fat depot. The lack of vitamin A supplementation also increased marbling compared with vitamin A supplementation in a study of Angus crossbred steers [133]."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6039335/
Quote from Ourania on May 27, 2021, 1:51 amThank you for all this @jeremy This is reassuring. Maybe these animals are killed before their livers are full of vA and it spills into the meat.
Sure. Just to be clear, this is about the last few months of a grain fed animal's life, where the animal is fed a concentrate of several ingredients but mostly corn. There is already a lot of beta carotene in corn. The practice has been to add vitamin A supplements to this mix. The newer studies have said this extra vitamin A supplementation might be a bad idea because there is not enough marbling. It is not clear whether producers are paying attention to these studies and reducing the amount of vitamin A supplementation in these animals' diets. I believe each feedlot owner would have his or her own staff nutritionist to make these decisions.
I tend to agree with liver-lover Paul Saladino and think of marbling as evidence of an unhealthy animal, for what it is worth. You wouldn't want to have marbling or intramuscular fat in your own muscles!
It is when reading threads like these that I start to question the sanity of people on this forum.
I'd rather eat grass fed any day of the week, regardless of its supposed vA content. Just use some common sense when you buy your meat: if the fat's got too much of a yellow tint, go for a whiter one or, ideally, a leaner one. I find it funny how you guys take the maximum recorded value and run away with it.
I don't think grain fed meat is that bad if it's organic, but to call grass fed meat the lesser of the two seems idiotic, especially when knowing it's what the cows thrive on.
Bison or buffalo are most likely going to be better choices, as mentioned above, due to their better carotenoid conversion.
But if all you got access to is beef, I'd rather eat some lean grass fed beef than grain fed meat, which not only tends to be fattier, but probably also has a worse vitamin and mineral profile, given its more washed out color.
LOL @andrei, I get you that this whole idea is crazy, but what about going low-vitamin A is natural/sane ? We live in THIS world, and it's chock full of vitamin A!
I think there is no static statistic "beef has this amount of carotenes" because every single beef in the world is going to vary according to what it ate, and what it's mother ate, and even it's grandmother.
My friend next door raises pigs, and she feeds them all sort of high carotene foods like baskets of peaches and squashes. Her free-range pig fat is going to be sky high with VA. The grain fed one at the store will be lower.
@salt is a very serious person who keeps her carotenes ultra low. I think it is very interesting if she is having symptoms of carotenes from free-range beef.
There is no zero-VA diet on the Earth....
We here, "The VA Toxic", are all goofed up with jammed-up detox pathways and so we have problems with lots of things that are natural and good.
We have to pick and choose carefully. The health benefits of something might outweigh it's carotenes. But you can't do that high-carotene food 24-7 or you might not make progress.
And I do think we all need to explore the "antidotes".
Let me try to summarize what I think I found in the academic research yesterday as well as some common sense. And thanks for @salt for getting us started.
- The common practice in the United States has been for feedlots to give vitamin A supplements. If an animal is given retinol or beta carotene supplements and then slaughtered a month after supplements are stopped, the meat will have VERY high retinol in it. Like off the charts high. The Chinese study is super clear about this. If the vitamin A supplements are stopped two months before slaughter, then retinol levels are closer to the baseline levels in the non-supplemented animals in that study (which themselves are also very high compared to database values).
- There is some literature on vitamin A supplements given to younger cattle, which would be grazing on grass. I haven't looked into supplements for younger cattle. Also, there are studies on vitamin A supplements for milk cows but I assume no one here is consuming dairy.
- If you buy meat at a chain supermarket, common sense says that you will have no idea which feedlot fed your cow and there will be no one to contact to ask whether vitamin A supplements are given. An industrial producer probably wouldn't welcome phone calls about dietary practices from consumers, given the number of angry vegans running around. For local ranchers selling at a farmer's market or ranchers selling via mail order, there is someone to ask. The person at the farmer's market or the person responding to email might not know though. I would look for a super detailed and convincing answer. 🙂
- I have no idea about the practices of grass fed ranchers as regards to vitamin A supplements. Grass fed ranchers are heterogeneous, with some doing the minimum to sell their meat as grass fed to supermarkets and others being more regenerative. I will send emails out to some regenerative ranches.
- Grain finished cattle are finished on mostly corn in the United States and corn contains beta carotene and the more yellow carotenoids. It is reasonable to think corn contains less beta carotene on average than green grass, so a grain finished cow not fed supplements could contain less vitamin A (retinol with less beta carotene) than a grass finished cow. Presumably the carotenoid content of any particular plant fed to a cow could depend on fertilizers, rainfall, sunshine, temperature, soil quality, etc.
- Grain finished cattle can contain all sorts of other crap they are fed in "concentrates" and that might also vary across feedlots for all sorts of reasons.
- Glyphosate, other herbicides and also pesticides could be sprayed on any plants fed to a cow and could be in the water a cow drinks. An organic ranch would try to minimize the food angle and an organic ranch far away from runoff from conventional farms and ranches would be best.
- The biggest issue is that the recent Chinese study of grain fed cattle and the recent Japanese study of Egyptian grain and grass fed cattle both find much higher levels of retinol in muscle meat than older studies and presumably older data in US government food databases. It is possible these newer studies use improved measuring technology. It is also possible the newer studies are wrong or misleading for some reason. Based on the newer studies, consuming beef daily would get you to the RDA and above even if you eat no other vitamin A, according to these studies. So we have no idea of the order of magnitude of vitamin A in either grass fed or grain feed beef right now.
I am sorry to be the bearer of bad news.