Beef, why it's a good choice for your health...part two

I know I said I was going to talk about the positive effects that beef has on the environment. But I just wanted to share more information on the health benefits beef provides to human health before moving onto another topic. So, hang with me! This is very interesting and a good selling point for beef!

You hear a lot about grass-fed beef these days but what is all the hype about? Is there a real difference in nutritional value between 100% grass-fed beef vs. grain-finished beef? The answer is yes. However, grain-fed beef is still high in nutrients and an important source of essential amino acids, vitamins A, B6, B12, D, E, and minerals, including iron, zinc and selenium.  I also want to note that all cattle start out as grass-fed. It isn't until they are finished in a feedlot that they become grain-fed. Keep reading to find out the specifics. 

Prior to the 1950's, most beef produced was from cattle finished on grass. The transition to grain was done to improve efficiency of beef production. Thus, the feedlot industry was born. High energy grains are fed to cattle as a way to decrease days on feed and improve marbling. The U.S. consumers have grown accustomed to the taste of grain-fed beef. (YUMMY!) But was nutrient dense meat sacrificed during the process? Most likely. But today grass-fed beef is making it's way back into the mainstream markets and dinner tables across the U.S.

Regardless of the genetic makeup, gender, age species or geographic location of the cattle, grass-fed beef consistently demonstrates significant differences in overall fatty acid profile and antioxidant content. Over the past thirty years health professionals world-wide have recommended a reduction in overall consumption of saturated fats, trans-fatty acids and cholesterol, while encouraging the increased intake of polyunsaturated fats. These recommendations are based on epidemiological studies showing a correlation between cardiovascular disease (CVD) and fat consumption. However, more recent research studies suggest that not all saturated fatty acids have the same impact on serum cholesterol. I won't go into the specific types and details of the studies but they show that leaner beef products can reduce plasma LDL (low-density lipoprotein - the "bad cholesterol") concentrations in both normal and high cholesterol, theoretically reducing the risk of CVD. 

Nutrient breakdown of Grass-fed beef and benefits to our bodies

Omega-3 and Omega-6 Fatty acid

These are two essential fatty acids. We are unable to synthesize them, so we must consume them in our diet. They are critical to human health. "A healthy diet should consist of roughly one to four times more omega-6 fatty acids than omega-3 fatty acids. The typical American diet tends to contain 11 to 30 times more omega-6 than omega-3, a phenomenon that has been hypothesized as a significant factor in the rising rate of inflammatory disorders in the U.S." (1) Omega-3 is a precursor for EPA, DPA, and DHA. Research shows that EPA and DHA play a crucial role in the prevention of atherosclerosis, heart attacks, depression, cancer and reduces inflammation caused by arthritis. In addition, the brain needs a high requirement for DHA; low levels of DHA have been linked to low brain serotonin levels, which are connected to an increased tendency for depression and suicide. 

How does all this medical jargon relate to grass-fed beef? Grass-based diets in beef vs. grain-fed have significantly higher levels of omega-3 , while the omega-6 levels are left unchanged. In fact, as the grain intake increases in cattle's diet, the omega-3 decreases . Grass-fed beef has a more favorable omega-3:omega-6 ratio. Seafood is the major dietary source of omega-3 fatty acids, but a recent survey indicated that red meat also serves as a significant source. So, move over salmon, beef is moving in! 

Conjugated linoleic acid (CLA)

This fatty acid is found in meat and milk of ruminants. I'm not going to go into the pathology of how CLA occurs in the rumen but just know that grain consumption has been linked to the decrease in the amount of CLA and can explain why grass-fed beef is much higher. Why is CLA important to us? "Over the past two decades numerous studies have shown significant health benefits attributable to the actions of CLA....Including actions to reduce carcinogenesis, atherosclerosis, and onset of diabetes. CLA has also been reported to modulate body composition by reducing the accumulation of adipose tissue." (1) CLA has also been proven in studies as a cancer fighting source. This powerful fatty acid helps fight disease and keeps the weight off. Should I say more?

Vitamin A and Carotenes

Carotenes are precursors to vitamin A, a critical fat-soluble vitamin that is important for normal vision, bone growth, reproduction, cell division, and cell differentiation. Vitamin A is responsible for  maintaining the surface lining of the eyes, respiratory, urinary, and intestinal tracts. Overall integrity of skin and mucous membranes are maintained by vitamin A. The skin creates a barrier to bacterial and viral infections. Vitamin A also plays a critical role in immune function with the production and function of white blood cells. 

Now that I've got you up to speed on the benefits of vitamin A to our bodies, let's talk about how grass-fed beef plays a vital role in obtaining this crucial vitamin. Cattle on high forage rations pass a portion of the ingested carotenoids (compounds that are synthesized by plants) to their fat and milk. This is what gives grass-fed beef the yellow carcass fat. The yellow fat has a higher fatty acid profile and a higher antioxidant content. It's been studied that grass-fed animals have 7 times higher levels of carotene than grain-fed animals. That is quite significant. 

Vitamin E

Vitamin E is an antioxidant that protects cells against the effects of free radicals. If you're not familiar with free radicals they are potentially damaging by-products of metabolism that may contribute to the development of chronic disease such as cancer and cardiovascular disease. Vitamin E has also been linked to block the formation of nitrosamines (nitrates consumed in the diet and are carcinogens formed in the stomach). Vitamin E also enhances immune function. 

Here's what you have probably already guess. Grass-fed beef has higher levels of vitamin E than their grain-fed counterpart. 

Antioxidant Enzyme Content

Here I’m going to share a little bit about a relatively new protein identified as glutathione (GT). It functions as an antioxidant. Within it’s cell GT has the ability to quench free radicals, in turn protecting the cell from oxidized lipids or proteins and prevent damage to DNA. The research on GT in food sources is limited since it is relatively newly discovered. But it is known that very little amount is contained in dairy products, eggs, apples, beans and rice. But fresh vegetables and freshly cooked meats, ham and beef, are high in GT. 

Grass-fed beef tested higher than grain-fed in GT content. It is also noteworthy to mention that other antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) are higher in grass-fed beef. “Grass only diets improve the oxidative enzyme concentration in beef, protecting the muscle lipids against oxidation as well as providing the beef consumer with an additional source of antioxidant compounds.” (1) 

There are numerous studies that show the benefits of grass-fed vs. grain-fed beef. For all of you grain-fed fans out there (I’m one!) it’s been shown that any lean beef, regardless of feeding strategy, can be used interchangeable with fish or skinless chicken to reduce serum cholesterol levels in patients with elevated cholesterol. Woohoo! 

If you’ve made it this far into the post I applaud you. That was pretty long winded. It must be the nurse side of me that finds nutrition so fascinating and I just wanted to share some knowledge. After all, the best type of medicine is to teach people how not to need medicine! 

Citations/References

Daley, Cynthia A., Amber Abbott, Patrick S. Doyle, Glenn A. Nader, and Stephanie Larson. “A Review of Fatty Acid Profiles and Antioxidant Content in Grass-fed and Grain-fed Beef.” Nutrition Journal Nutr J 9.1 (2010): 10. Web.