Grass-Fed Meat vs Grain-Fed Meat: Part 1

grass-fed vs grain-fed beef
Share:Tweet about this on TwitterShare on FacebookPin on PinterestShare on Google+Share on LinkedIn

To say one food is better than another, you have to prove it contains more nutrients and less toxins.  This is the underlying principle of the Bulletproof Diet.  The goal is to provide maximum nutrition with minimal damage.

Grass-fed meat fits this criteria perfectly.  It contains more antioxidants, omega-3’s, CLA, TVA, trace minerals, and vitamins than any other food, including conventional meat.

As you’re about to learn, consuming grass-fed meat is one of the best ways to prevent disease, improve brain function, lose weight, and become Bulletproof.

Let’s begin.

The first study we’ll look at was published in 2006.  It measured the fatty acid composition of grass-fed versus grain-fed meat.  Before we dive into the research, here’s what you need to know.

1. Omega-3 fatty acids are an essential component of nerve tissue.  They modify how the body responds to stress and control numerous other metabolic processes.  Most people eat too many omega-6 fats and not enough omega-3.

2. CLA is a type of naturally occurring trans-fatty acid that improves brain function, causes weight loss, and reduces your risk of cancer.

What a steer eats dictates how much of these compounds are in the meat.   This study compared how grain feeding effects this process.


Study #1: 2006

Effect of feeding systems on omega-3 fatty acids, conjugated linoleic acid and trans fatty acids in Australian beef cuts: potential impact on human health.

Researchers compared the fatty acid compositions of three kinds of feeding.  Each group contained 18 Australian cattle.  The first group was fed grains 80 days before slaughter, the second group was fed “by-product feedstuff” for 200 days, and the third group was grass-finished and grass-fed.

Group #1: Short Term Grain Feeding (80 days)

Group #2: Long Term Feedlot Rations* (150-200 days)

Group#3: Grass Feeding (Life time)

*Feedlot rations for australian beef are made of 50 percent barley and/or sorghum (a type of wheat) and some form of cottonseed/protein mix:  A mixture of grains.



The grass-fed cows had more omega-3’s and conjugated linoleic acid (CLA).  Just 80 days of grain feeding was enough to destroy the omega-3 content of the beef.  CLA content plummeted in the same amount of time.  The longer the animals were fed grains, the lower the quality of the meat.

“There was a significantly higher level of total omega-3 (n-3) and long chain n-3 FA in grass-fed beef than the grain-fed groups regardless of cut types.”

The omega-3 quantity in grain-fed meat was so low, it didn’t qualify as a meaningful dietary source.  Grass-fed meat has enough omega-3 to be considered a good source of n-3 fats.  As Chris Masterjohn has shown us, the total amount of omega-3 we need is small if you have a good omega-6 to omega-3 ratio.  Therefore, eating grass-fed meat along with some fatty fish may be enough to cover your omega-3 needs.

“Only grass-fed beef reached the target of more than 30mg of long chain n-3 FA/100 g muscle as recommended by Food Standard Australia and New Zealand for a food to be considered a source of omega-3 fatty acids.”

Grain feeding significantly reduces the omega-3 and CLA content of meat.  The feedlot cattle had the lowest levels, the grain-fed cattle were in the middle, and the grass-fed cattle had the most.  The longer an animal is fed grains, the lower the nutrient content of the meat.



  • Grain-fed beef is much lower in omega-3’s and CLA
  • The longer steers are fed grains, the lower the omega-3 and CLA content.
  • Feedlot cattle have the lowest amount of omega-3‘s.  Regular grain-fed cattle are slightly better.
  • The last part of a cow’s life is the most critical in terms of fat quality.

Meat can be a good source of omega-3’s, if it’s grass-fed.  Grain-fed meat has lower levels, so you’ll need to eat a lot of cold water ocean fish or take fish oil supplements to reach your daily omega-3 requirements.  Grass-fed meat has more healthy fats than grain-fed meat.

This study only covered a few types of fats.  The next study in this series shows how grass-fed beef has a broad spectrum of beneficial fats and other nutrients that are missing from grain-fed meat. Check it out here.


If you’re looking for a 100 percent safe source of grass-fed beef, we recommend Alderspring Ranch.


Some background research for this post may have been conducted by Bulletproof staff researchers.

Share:Tweet about this on TwitterShare on FacebookPin on PinterestShare on Google+Share on LinkedIn

By Dave Asprey

  • Caleb

    Hey great stuff so far.

    So from what I can tell (re-read the study 5x) NONE of these groups were what we would call “grass finished” right?

    It appears they were grain finished?

    I’m interested to see you cover grass finished beef, i.e. cattle fed grains to fatten them up, then switched to grass finished before slaughter. From the little I’ve heard it seems like a good compromise VS full grass fed beef.

    Great so far, keep it up!

    — Caleb

    • You’re right Caleb, this study was limited in it’s analysis. We cover several more studies like you requested in later articles – to be released 🙂 You’ll find the results interesting.


    • I think what you are saying is not a real option. Cattle are never (or not that I’m aware of) raised on grain and then switched to grass. That’s the wrong way round. They are ruminants and cannot be raised well on grain, as it is not natural or healthy for them. They are either reared wholly on grass (sometimes with other forage), or reared on grass and then fattened on grain, or reared on an intensive grass with high-protein feed diet and then fattened on grain. It would be no point finishing a grain-reared cow on grass, as it wouldn’t fatten.

      The fattening stage is the last stage and needs a higher-protein food than grass. However, the protein source can (should) be more natural foods such as legumes (along with grass), not grain.

      I may have got a few details wrong, but this is my understanding.

    • MonFille

      I’ve raised four grass-fed steers from my own cow–3/4 Guernsey 1/4 Angus crossbreed…full of beta carotene, Omega 3, and CLA., and A2 beta casein…and drank the milk and made butter [very golden in color and tastes like real butter]. Fact is, to get the same amount of Omega 3 into one’s diet, you would need to eat cold-water fish [salmon, cod, etc.] about every night of the week. I do not like fish very much and really can hardly stand the smell of it in my house! So, I’ll stick with the beef. Besides, I fifure that if one has pointe eye teeth, one is supposed to be a carnivore…and I do…and my European ancestors have benn beefeaters for centuries back. It was meant to be.

  • Whitphotography

    I’ve been wondering if some of these benefits are lost when eating hamburger patties that are for example 75 percent lean. How’s the other 25 percent of added fat effecting things?

    • Are you talking about hamburger that’s grass-fed or not?

    • Don’t worry about the fat if it is grass-fed beef. It is the fat that contains the important fatty acids and fat-soluble vitamins!

    • Have never seen 75% lean grass fed. Where do you find that? Where I get it they only sell 90% lean.

      • MonFille

        Buy a meat grinder and grind the fattier cuts of beef yourself. I did that for years, before I got my own Guernsey hybird cow.

  • Pingback: Crossfit WOD :: Crossfit Dublin()

  • Pingback: Nothing found for ?p=372()

  • Pingback: #5: How To Quantify Fatigue Like Never Before | The Bulletproof Executive()

  • Dan

    I have no doubt that grass fed is better than grain. However, it will be extremely difficult to follow this diet if all meat has to be grass fed. How important is it for the meat in the diet to be grass fed?

    • It’s important, but not as much as eliminating things like bread, grains, sugar, and damaged oils. It’s also not as hard as you might think. We’ll be covering that in the series too. Great question.


    • Dan,

      Something Robb Wolf suggests as a 2nd best option to grass fed, is eating lean meat and supplementing with fish oil.

      • That’s a good alternative, but unfortunately it’s not the same. Omega-6’s decrease your ability to process omega-3’s, and all PUFA’s are highly unstable and potentially inflammatory. It’s a good plan, but you can take too much fish oil.

        Great comment Alexis,


      • M G

        Unfortunately, the pursuit of breasts (chicken breasts) has caused so much harm tot he chicken industry. Watch food inc. And see what I mean.

  • Pingback: Why Grass-Fed Meat Is Healthier Than Grain-Fed: An Epic Series | The Bulletproof Executive()

  • Sean

    I want to add this to the hive-mind here… Omega 6/3 info on grass-fed versus grain-finished cattle:

    “Ducket et al [“Effects of winter stocker growth rate…” @] found that grass-finished and grain-finished beef had, respectively, 1.65 and 4.84 times as much omega-6 as omega-3 fat, but, as noted, the absolute amount of omega-6 did not differ significantly between the two finishing strategies. Thus, grain-feeding does not increase the omega-6 content, it only decreases the omega-3 content, of the meat.
    –Meat from grass-finished animals given no growth promotants had about 50% more omega-6 fatty acids than animals given growth promotants regardless of feed type.
    –The more grain given to animals, the lower their omega-3 content of their meat, in a dose-dependent fashion (same finding as Ducket et al above).
    –Meat from exclusively grass-finished animals had 2.5 times as much omega-3 fatty acid as meat given a finishing diet of 70% grain.


    • Sean, you’re my new best friend 😉 Thanks for the awesome info and I may do some more work with that study.

      • Sean

        Yeah, it’s a treasure of interesting info… Three separate posts, “The Practically Primal Guide to Conventional Beef” … Another I like, from “Part 1, Hormoes”:

        They found no significant difference in hormone levels between meat from hormone-treated and untreated animals. In the typical diet, meat, poultry, and eggs proved to supply less hormones than non-paleo milk products :
        “Meat does not play a dominant role in the daily intake of steroid hormones. Meat, meat products and fish contribute to the hormone supply according to their proportion in human nutrition (average about one quarter). The main source of estrogens and progesterone are milk products (60-80%). Eggs and vegetable food contribute in the same order of magnitude to the hormone supply as meat does.”
        Thus, if you eat a paleo diet, and avoid milk products, you actually would eliminate the greatest dietary source of estrogens, and might reduce your total dietary intake of estrogens by more than 50%.

        • Great stuff Sean. I’ve got some more articles on the hormone issue, among other things, related to meat and dairy. Keep up the great info scavenging!

  • Hey Bulletproof Community! I’ve been struggling…what’s worse? Eating a paleo diet based on gran-fed meat and low quality vegetables or sticking to a vegetarian diet with lots of nuts, fruits, etc. Currently I live on a college campus where you are required to have a meal plan. I can’t help but think about low quality and anti-biotic filled meat so I often try and avoid it. I do try and compensate but drinking whey protein and taking supplements. Any suggestions?

    • I would say better stick with your vegetarian diet with lots of nuts and fruit, but also eat oily fish once a week. It would probably be healthy to occasionally eat some meat (grain-fed if you can’t get grass-fed). However, for animal welfare and other ethical reasons, really no one should ever eat grain-fed meat!

      • John

        I eat mostly carnivorous, veggies are an afterthought. Thanks for your opinion but I already have a steak cooking.

        • Ryan Critchett

          LOVE IT.

      • Ryan Critchett

        This argument. For animal welfare? — You’re applying logic, and idealism to a nature based situation. I know, I’ll never convince you to think differently, so I won’t try. I will however, have awesome brain performance.

        Giving people advice to avoid beef is probably dangerous. So is giving them advice to eat grain fed meat. But – I don’t (again) wish to/hope to/expect to convince you. If you’re saying what you commented above, you’re far gone. And this comment will probably make you defend your point more – but don’t use that as your compass for deciding how to think about this stuff. Use other protocols, like how you feel perhaps? Performance? All around health? Now and in 50 years? Many more.

        Anyway — the ideology and “ethics” over natural processes, and biological reality, is harmful.

    • Ryan Critchett

      Go grass fed meat. What’s preventing that? — I’d cut out all information about any of this, you’ve accumulated. Start eating Grass fed steak, a couple times a week, some good grass fed butter, get veggies (broccoli, asparagus, others), eat eggs, drink water, meditate, exercise, sleep solidly, and do everything you can to minimize stress. – How do you feel when you do that? That’d be the best way to determine what to eat, and what protocols to engage food wise, care wise, etc. —

      • Aaron Graves

        Only eat grass fed butter a couple times a week? What’s wrong with eating grass fed butter more than a couple times a week?

  • You are saying some really wrong things here. Yes, grass-fed meat is much healthier than grain-fed beef, with higher levels of vitamins, minerals, omega-3 etc. But it certainly does NOT “contain more antioxidants, omega-3’s, CLA, TVA, trace minerals, and vitamins than any other food” !! There are plenty of foods with higher levels of all these nutrients.

    For example, grass-fed beef is not a particularly great source of omega-3. People should around eat 1g of omega-3 per day, but 100g of grass-fed beef only provides around 0.09g! In comparison, if you eat salmon, you will get 2g per 100g. Sardines and trout are other great sources.

    The only mineral that beef contains unusually high amounts of is zinc. It also has really good amounts of B vitamins.

    Overall, it is a fairly good food, but there are plenty of more nutritious foods! Please correct your information.

    • Luke

      youre nitpicking. Im sure he is talking about the combination of fats,vit and minerals not the individual quantities..

    • MonFille

      You would have to eat cold-water fish about every night of the week to get the same amount of Omega 3 into your diet as having the grass-fed beef a few times a week. I found that on some of the earliest reports of this same message. Read everything on the Net about subject before making any further comments. I’ve had my own cow since late ’01 and done massive amounts of research in bovine husbandry over the years…14 of ’em.

  • Pingback: » Step 2: Upgrade Your Energy Supply: Optimize Your Supplements The Bulletproof Executive()

  • Pingback: Dietary Must Reads 3 |

  • Pingback: Interview with Dave Asprey the Bulletproof Executive | Renegade Dad()

  • Pingback: Wednesday Linkup: Grass-Fed is Great | Well Rounded Mama()

  • Jbug

    I went to the alderspring ranch website and it says the beef is “dry aged” i thought dave said we want to avoid dry aged meat and go for stuff thats frozen right away. is that right or did i misinterpret?

  • Pingback: Cleansing and Getting Bulletproof()

  • Pingback: Mighty Omega-3′s « CrossFit Rhodes()

  • Ryan Critchett

    Yep. Love it.

  • Pingback: Step 7: Identify & Remove Toxins That Limit You()

  • Pingback: What you didn’t know about grass fed meat | Eat Drink Paleo()

  • Pingback: Cube Steak & Gravy()

  • Pingback: Best Paleo Foods What you didn’t know about grass fed meat | Best Paleo Foods()

  • Pingback: » Meet Your Meat: 6 Tips Once Upon a Paleo()

  • Duke

    Is Omega-3 the only nutrient that is beneficial from the grass fed meat? If it is, and its hard to get good grass fed meat. What is wrong with getting omega 3’s from freshly crushed flaxseed and eating walnuts? That seems so much easier and would help lower the protein intake of western society which gets too much protein in general. Thoughts?

    • Lucca Mordente

      Looks like omega 3 from plants need to be processed in our body before it can be absorbed. Some sources point that the absorption rate can vary from 20% to 30% and others says from 1% to 3%.

  • Hillary Gayle

    So I’m a starving college student who can write a whole long testimony on how this diet has been a god send for me. I’m following the diet to a T and loving it enough to keep at it but it definitely is expensive. I’m extremely passionate about good health, especially anything that applies to my health years down the road. And also brain function. I’m a physics major enroute to law school and high brain performance matters a LOT. To the point where this diet has become a dependency. I’m wanting to know how dramatic of a difference to my health, negatively, switching to grain fed meat would cause. If it’s a matter of grain-fed simply being LESS beneficial, I can save a lot of money and put it towards all the adventuring I want to do. (Until I land a job that’ll actually cut the meat for me, that is.)
    But Dave mentions quite a bit over quality of the product doing the opposite for you, putting you into a funk, as opposed to optimizing you for the day. (I’ve noticed this first hand with coffee). Because I’ve become to rely on that performance I really don’t want to take a chance in winding up in a funk.
    So, with me still following the diet through and through, would one change make a noticeable difference? And also, would something like having a 50/50 diet of grass fed/grain fed be better than all grain or is it best to keep that view black and white?

    This would only be a shorter-term (5 years max) change. Thank you all so much for any advice given!

    – HG

  • alex

    I have been trying to get access to the 2nd and third articles on the grass fed meat but havent been able to, any advice? please reply to me at if it isnt too much of an inconvenience

  • Meg Harrigan

    For someone who doesn’t have a gallbladder, eliminating excess estrogens is more difficult because the liver is often taxed, especially when encountering more fats.
    My question is: Is fat from animals (even grass-fed butter) a problem source of estrogen for those without gallbladders?

  • Pingback: The 4 Best Fats for Bulletproof Cooking()

  • Pingback: Can Vegetarians Eat The Bulletproof Diet?()

  • MonFille

    It’s why I have a cow — Guernsey, which also has the A2 beta casein component, supposedly also of health benefits. They, as well as Jerseys, have high beta carotene component, which converts to Vitamin A when consumed.

  • Lili

    Hi Dave and team! Huge fan!!! Is there a way to confirm that a local meat market is actually selling grass-fed meat? I have asked and they claim that all their meat is grass fed, but when I ask for their source, all they tell me is ‘Midwest’. One shop clerk went as far as specifying Wisconsin, but that is all they divulge. When I ask for a specific farm they do not provide. All of their meats are repackaged, so there is no label information on them. This seems evasive to me, is this normal? I would love to have a local shop that sells all the grass-fed meat our family buys, but how do I know that is what we are actually getting?

  • Pingback: How to Own Your Gut Bacteria and Fix Leaky Gut Syndrome()

  • Lyman Duggan

    Dave no mention of Vitamin K from cattle cud fermentation of grass with the soil bacteria Bacillus subtilis. You are missing one of the big befits of grass fed products. Maybe put Natto in your coffee?? Some research will be an eye opener for you.

  • Werner

    I eat only grass fed meat, organic eggs and organic butter .. nothing else. There are only two essential nutrients .. fat and protein. Carbs are a non-essential nutrient. So forget the veggies .. I am a second hand vegetarian … cows eat grass and I eat cows.

  • Pingback: How to Optimize Your Supplements | judeenterprises()

  • Pingback: PCOS - Friendly Foods - PCOS and Nutrition()