Blog Topics:
1. What is grass fed beef?
2. Saturated fat in grass vs. grain fed
3. Unsaturated fats in grass vs. grain fed
4. Omega 3:6 ratio in grass vs. grain fed
5. Other Fats, Vitamins & Antioxidants in grass vs. grain fed
6. Conclusions
1. What is grass fed beef?
Moooooooo!!!! Grass fed beef is everywhere these days. Besides the fact that my nearest Aldi carries it for $5.29 a pound (no endorsements there lol!), what makes it different than all of the other stuff on the grocery store shelf. Simple, they don't feed the cattle grains. They are able to forage on pasture (ideally), but are nonetheless at least fed grass even if they are raised in an area that doesn't allow for being out on pasture year round. The guarantee here is that they aren't given corn or other grain as is done with conventional farming practices.
Be careful though because some beef can be misleading in that it is grass fed, but not grass finished! This is a bummer because the farmer takes all the time to feed it grass which confers some health benefits that we will get into later, and then pumps the cattle full of corn to fatten it up for slaughter. As you will see, there is a noticeable difference between the nutrient contents of grass fed and grain fed beef.
2. Saturated fat in grass vs. grain fed
Don't let saturated fat scare you. That's a topic for another blog but when it comes to comparing saturated fats in grass vs. grain finished beef, there isn't a huge difference, but a slight one.
Saturated fats are classified based on their length. By length I mean how many carbons are in the fat chain. Grain fed beef contained higher amounts of myristic (C14:0) and palmitic (C16:0) saturated fats than in grass fed beef. Both of these saturated fats are known to have a cholesterol elevating effect. On the other hand, grass fed beef had higher levels of stearic acid (C18:0) which has not been shown to increase cholesterol levels.
Whether or not the saturated fats may elevate cholesterol levels is not of the utmost importance here to me. That is for another blog. The point is, while there are minor differences, this isn't what makes it or breaks it for me. Let's move on.
3. Unsaturated fats in grass vs. grain fed
Grain fed beef actually has more MUFAs (Monounsaturated fatty acids) than grass fed beef. And MUFAs are inversely associated with cardiovascular disease. Other sources of MUFAs are olive oil and avocados. MUFAs are closely associated with the Mediterranean diet which has been a popular health diet. This statistic favors grain fed beef when looking at this variable in isolation, but that's not the end of the story.
4. Omega 3:6 ratio in grass vs. grain fed
Now, lets get to the Polyunsaturated fatty acids (PUFAs). Omega-3s and omega-6s are two types of PUFAs. The omega 3s promote the anti-inflammatory pathway, and the omega-6s promote the inflammatory pathway. They are both broken down using similar enzymes or molecules in the body. This just means that too much of one can influence how much of the other one gets broken down. It's sort of like all of them jumping in a single file line to walk through a door. If there's a lot of omega 6s in line, the omega 3s are going to be fewer in concentration than if there weren't so many omega 6s. And in the case of grain fed beef, this is exactly what happens.
Here's the moment we've all been waiting for... It has been shown that the average omega 6:3 ratio in grass fed beef was 1.53 whereas the grain fed ratio was 7.65! So what's that mean to you? When you eat the grain fed beef, all of the omega 6 fatty acids will "out compete" the omega 3 fatty acids and the result is that your body incorporates a higher than normal amount of omega 6's into your tissues.
Okay, so what's the big deal? I've got a few more number 6's. Hold your horses. It is suggested that a healthy diet should have roughly 4 times as many omega-6s as omega 3’s. We can call this a 4:1 ratio. The problem is, our current American diet makes for a fatty acid ratio between 11:1 and 30:1. Remember earlier how I said that the omega 6's promote the inflammatory pathways (associated with disease states) where the omega 3's promote the anti-inflammatory pathways? The moral of the story is that the greater amount of omega-3s in comparison to omega-6s, the better, and grass fed beef fits the bill for that.
5. Other Fats, Vitamins & Antioxidants in grass vs. grain fed
Conjugated linoleic acid (CLA) is a fatty acid that is also generally higher in grass vs. grain fed cattle. CLA is made in the rumen (the first stomach) of the animal by a bacteria called Butyrivibrio fibrisolvens. The thing is, this bacteria only thrives when the animal can eat grass in order to make decrease the acidity of the rumen (raise the pH). I guess the lttle critters like it not too acidic. The bacteria can then create CLA through a process called biohydrogenation.
When you pump the animal full of grains, you increase the acidity of the rumen (lower the pH), the Butyrivibrio fibrisolvens don't thrive, and not near as much CLA is produced. Ruminant species like cattle produce 2-3 times more CLA when fed grass compared to those grain fed. But why does that matter? CLA is beneficial for reducing cancer, atherosclerosis, and diabetes onset. Additionally, it helps with body composition by decreasing the amount of adipose tissue (fat) at very high doses. Another win for doing it natures way (eating grass).
Vitamin A: Pasture raised beef shows a significantly higher amount of beta-caroene in the muscle tissue when compared to grain-fed roughly by a factor of 7! No wonder people take multivitamins lol! Carotenes are precursors to retinol, also known as Vitamin A. Vitamin A helps with vision, immune system function, maintaining the lining of skin and mucous membranes, and bone growth.
Vitamin E: Grass fed has much higher levels of a-tocopherol (Vitamin E) than their grain fed comrades. Vitamin E functions as an antioxidant that helps protect against free radical production. Free radical production may play a role in numerous disease processes like cardiovascular disease.
Glutathione: Glutathione is a very potent antioxidant that protects the cell from oxidation and prevents DNA damage. Glutathione is found in greater amounts in grass and forage that the grass fed cattle prey on (do cows prey on grass?), compared to grains. This leads to higher concentrations of glutathione in grass fed livestock. Other antioxidants like superoxide dismutase and catalase are also found in higher concentrations in grass fed beef.
6. Conclusions
Well, there ya have it folks. Grass fed beef is certainly more expensive than conventional grain fed beef, but grass fed beef may incur some important health benefits. Grass fed beef has fewer cholesterol elevating saturated fatty acids (although the importance of this is questionable to me), it has LESS monounsaturated fatty acids which isn't a feather in the hat, has a significantly better omega 6:3 ratio that promotes the anti-inflammatory pathway, has higher amounts of conjugated linoleic acid which may help prevent some diseases, has higher amounts of Vitamin A precursors and Vitamin E, and contains more potent antioxidants like glutathione, superoxide dismutase, and catalase.
You made it! I hope that I've helped unravel the grass fed cattle mystery for you. Next time you're chomping on a grass fed burger or a juicy slab of meat, remember some of these tre(mooooo!)ndous benefits!
Daley, Cynthia A et al. 2010. A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef.
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