I get this question a lot, and for good reason. Grass-feed beef is more expensive and often not as easy to find as grain-fed. The quick answer is that I definitely think grass-fed beef is better in many ways and IS worth the extra money. Let’s dig into why!
There are two issues to consider here: 1) is grass-fed beef more nutritious than grain-fed beef, and 2) does grass-fed beef have less TOXINS than grain-fed beef? The second question is the one that is seldom answered, yet the one that I think is most important. Let’s answer the nutrients question first and then move on to the toxins question.
Is grass-fed beef more nutritious?
There are not a ton a studies addressing the nutritional differences between grass-fed and grain-fed meat, but there are a few. This is one of the better ones I have found:
As we can see from this study (illustrated by the table above) (G= Grain-fed, P= Grass-fed, +E= supplementation with vitamin E), grass-fed animals had higher levels of vitamin E (denoted in the chart as alpha tocopherol), beta carotene (precursor to vitamin A) and vitamin C. Yes! Meat does have vitamin C. Interestingly, if you do the math, grass-fed meat has about 11.3 mg of vitamin C per pound (454g) and grain-fed meat has roughly 7.3 mg per lb. The notion of vitamin C in animal foods deserves a whole post of its own, but the takeaway message here is that fresh meat contains enough vitamin C to prevent scurvy, and many of the other organs such as liver, kidney, and brain contain even more vitamin C than muscle meat. Critics often cite concerns about lack of vitamin E on a carnivore diet (see my response podcast to critiques against the carnivore diet here) but if we do the math, we can see that muscle meat contains a moderate amount of vitamin E. Again, grass-fed is a richer source of vitamin E than grain-fed. When combined with organs and egg yolks, a nose-to-tail carnivore diet can provide more than adequate vitamin E for humans. Interestingly, on the most recent set of labs I had done, my vitamin E was at the high end of normal!
Though there are many nutrients that we could consider in this discussion, another I would like to highlight is coenzyme Q10. This is a molecule that the human body can make, but that we can also obtain from food. It’s an important part of our system to manage oxidative stress, and it serves a vital role in the mitochondrial electron transport chain, which is how we make energy as ATP. CoQ10 occurs naturally in animal muscle meat, and is especially rich in heart (nose-to-tail for the win! See the “What to Eat on Carnivore diet” blog post to learn more). Though there is only a small amount of data, levels of CoQ10 are estimated to be much higher in grass-fed vs grain-fed animals. Anecdotally, I will add that the clients I see who are on a carnivore diet have extremely robust CoQ10 levels in their blood. My own numbers are 2.38 ug/ml, which is quite high (a good thing!). In summary regarding nutrients, we can see that grass-fed meat is richer in many nutrients than grain-fed meat, but the latter can still be a good source.
Since we are discussing the RDAs (recommended daily allowances), I’d like to point the reader to my podcast with Amber O’Hearn. Amber has given some great lectures discussing the idea that RDAs have been developed on carbohydrate based diets, and that in ketosis, some of the needs for nutrients might be lower, and some may be higher, as is probably the case with sodium. We clearly need more nutritional research on low-carb populations. Look for a future podcast all about blood work where I will discuss possible variations in labs for those following a ketogenic diet.
What about toxins in grass-fed and grain-fed meat?
I think the real nitty-gritty of the grass-fed vs grain-fed conversation is found when we consider the things grass-fed meat, does NOT have in it. Specifically, I am referring to pesticides of a variety of types which are sprayed on the grains that feedlot cattle are fed. There are water soluble pesticides, like glyphosate (roundup) and 2-4,D, both of which likely end up in the muscle meat of grain-fed animals. Glyphosate is sadly now pervasive in our environment, and we are only just beginning to appreciate the negative effects that it may have on human physiology. There have been a number of recent court cases ruling in favor of defendants claiming that glyphosate exposure contributed to cancers. Dr. Stephanie Seneff has also done a large amount of work which suggests possibly detrimental effects of this compound in our bodies and in our guts disrupting the microbiome. Think twice the next time you see that roundup display at Home Depot!
There are also fat soluble compounds like atrazine, which is sprayed on corn feed. Atrazine can act as a xenoestrogen, a molecule that mimics estrogen in the human body by binding to the 17-Beta estradiol receptor. These are bad news for both men and women. We don’t want compounds like this acting as hormonal disruptors. There are studies showing that atrazine can induce chemical castration in frogs and turn males to females! Yikes! There have been studies like this one comparing the estrogen content of American vs Japanese/Brazillian beef (grain-fed). These studies show that the American beef has a much higher amount of estrogen mimicking compounds in it, likely due to the chemicals on the grains fed to the animals while they are in feedlots. Double yikes!
There’s another one of these estrogen mimicking compounds called Zearalenone (sounds like an alien warlord, right?) that is sometimes fed to cows on feedlots to increase the cattle’s weight on a given amount of feed. I talked a bit about this with Dave Asprey on his podcast, Bulletproof radio. This compound is actually a mold toxin, known as a mycoestrogen, which can also occur when grains get moldy and are fed to cattle. These molds are also probably going to concentrate in the fat of grain-fed meat to a greater degree than grass-fed meat.
What about Dioxins? These molecules belong to a class of chemicals considered persistent organic pollutants because they do not break down once introduced in the environment. Lovely, right? The Weston A. Price foundation has a great article by Chris Masterjohn, PhD, which goes into great detail about Dioxins here. Dioxins in animal foods have been used as an argument against eating meat by advocates of vegetarian and vegan diets. There are many things wrong with these arguments, however. When the levels of dioxins have been measured across various countries (the Netherlands, Finland, Greece) in different foods, many plant products have been found to have very high levels of dioxins, and amounts in both plant and animal foods appear to vary considerably. Another problem with these arguments is that our levels of dioxin exposure have declined significantly in the last 50 years, since the removal of the chemicals from our environments. When we consider that the main sources of dioxin exposure presently is wood smoke, it seems likely that our current levels are on par with what our ancestors would have encountered cooking over open flames thousands of years ago.
Relevant to the grass-fed vs grain-fed question are research findings suggesting that above average levels of dioxins in beef are most likely due to exposure to feeding troughs constructed of pentachlorophenol treated wood and the inclusion of incinerator waste as a feed additive in feedlot cattle. Grass-fed animals would not be exposed to these sources of dioxin.
So what’s the take home message here? Grain-fed and grass-fed meat are both going be nutritious options as part of a whole foods animal based diet. Grass-fed meat appears to have higher levels of many vitamins including C, E, A, and CoQ10, and will likely have lower amounts of pesticides like glyphosate, atrazine, dioxins and mold toxins. To me, grass-fed is the clear winner here, and is definitely worth the extra cost. I can’t think of a better investment than my own health, and buying good quality food is a key part of this!