Beyond Grass and Grains – Part One: Nutrition

Western culture tends to split everything into binary opposing pairs. Such dialectical thinking permeates our thought process. So we have good versus evil, liberals versus conservatives, left versus right, East versus West, rural versus urban, black versus white, etc. Such thinking even permeates how we consume and produce food. So we also have vegans versus carnivores, organic versus conventional, degenerative versus regenerative, and meats versus plants.

Even more specifically, this dialectical thinking extends to grain or conventionally finished beef [CFB] versus grass finished beef [GFB]. Many memes have been made and arguments have been had over whether GFB or CFB is better or worse for one’s health and or the environment. As will be quickly demonstrated, this specific debate isn’t a binary argument. Why? As Dr. Fred Provenza likes to say, “grass fed isn’t grass fed isn’t grass fed.”  Especially in regards to the nutritional content of GFB, there’s a lot of variability with grass finished beef due to a long list of variables including, but not limited to, diversity and quality of forage, soil health, location, management, and genetics. So GFB isn’t any one thing.  CFB, on the other hand, strives for greater consistency by reducing and controlling many of these different factors. Many of these different factors will be outlined here below, and then discussed in greater detail in a Part Two of this blog entry. Part Two of this entry will focus more on the production and business model differences between GFB and CFB in the United States.

A recent study from Michigan State University (Bronkema et al, 2019) conducted a nationwide confidential survey of commercial GFB producers regarding their production methods specifically in regards to what types of forages these producers used to finish their beef. As part of this survey, participating producers submitted at least seven samples of their beef. All samples came from the anterior portion of the strip loin. In total 12 producers from 10 states participated in this study though only 9 provided their grass finishing feed information. Sampling and testing had very specific protocols. Of particular note, “a representative core of loin sample was taken, avoiding pockets of intramuscular fat.” This added bold face is a quite critical to understanding the results, and why the results from this study differed from prior results from other studies. For example in the MSU study, with the results for total fatty acids [FA], there was a wide range of results from the 12 producers that varied from 84.4 to 3,610 mg per each 100g beef sample. The mean total FA content for all of these producers was 723.4 mg per 100g of beef. As noted in the MSU paper, their mean was considerably less than two other relatively recent studies for GFB (De la Fuente et al 2009 and Chail et al 2016) that respectively reported means of 1,142 mg/100g and 2,982 mg/100g of beef. One possible reason given for this disparity was the sampling strategy that purposely avoided large fat deposits in the lean tissue resulting in leaner tissue samples than other studies. So, comparing the results from different studies is more than a bit problematic when different sampling protocols and testing methods are used.

Note too, more detailed fat analysis of the beef samples relies on this total FA number. So the total FA impacts the sub-total amounts of saturated fatty acids [SFA], poly-unsaturated fatty acids [PUFA]- including Omega 6’s and Omega 3’s- and naturally occurring trans fats like conjugated linoleic acid [CLA]. In the MSU study and other studies, there’s a large range in the amounts of SFA’s and mono-unsaturated fats. Though much less variability in PUFU’s and more specifically preformed Omega 3’s (EPA, DPA and DHA). In general, beef isn’t a great source of DHA no matter how it is finished. Total FA also impacts the amounts of fat soluble vitamins and phytonutrients (e.g. beta carotene) in the beef. Why? These vitamins and phytonutrients are stored in the fat tissue…not the lean muscle tissue. Contrary to what fat phobes claim, most forms of naturally occurring  fats are very healthy including saturated fats.

fat is good

There’s no federal USDA definition of what constitutes GFB. Some associations like the American Grassfed Association [AGA] have stricter protocols. For example, as the MSU study notes, at least two of the ranches that were part of MSU’s study would be excluded from being members of the AGA since these two ranches used soybean hulls as part of their finishing mix. With GFB, what feed is allowed or is used to finish GFB is just one of many variables that will affect the nutritional content of the meat. Climate, seasonal rainfall, time of slaughter, all impact the total fatty acid amounts and thus the fatty acid composition, phytonutrient and mineral content of the beef. The breed of cattle and a breed’s genetics matter. Grazing management also impacts the nutrient content. Why? Grazing management directly impacts the soil and plant health and thus the nutrient density of the plants that beef cattle eat. So if cattle continuously graze, as oppose to holistically graze, grass recovery may not occur and grazing may not be correctly timed. Therefore, cattle might be finished on the wrong phase of plant growth…that is on protein rather than on carbohydrates. When cattle is finished on protein, its beef is too lean. Not all ranchers know how to “read” grasses so a lot of GFB isn’t finished properly. Plant diversity matters as well. Diverse rangelands where cattle can self-select what they what to eat, will provide much different phytonutrient profiles in their fats than cattle finished on monocultures or on grass pellets in feedlot bins. Dr. Fred Provenza mentions the importance of diversity of forages in this discussion below on The Doctor’s Farmacy podcast with Dr. Mark Hyman. Yes, beef has phytonutrients in its fats. So plants are NOT the only source of many phytonutrients.

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The MSU researchers in their analysis speculated that their lower mean total FA- compared to other studies- may have also been due to the cattle in their survey consuming less overall energy (carbs) compared to the cattle in the other studies where the overall energy was more closely monitored. The MSU study did NOT compare any of its samples to feedlot conventionally finish beef (CFB) where feed rations are even more controlled, especially for energy, during the finishing phase of production. That’s one of the primary reasons for CFB…to reduce the variables to produce a more consistent commodity. GFB in some ways is more analogous to wine making since, like wine, GFB has a terroir. Plus the skills of a ranchers to finish his beef properly (from his specific herd and breed or cross breed of cattle) is akin to the skills of a vintner to produce the highest quality of wine from his specific varietal (or blend) of grapes.

Coincidentally, I knew one of the researchers from the MSU Study, Dr. Jason Rowntree. I met Jason at a conference back in 2015 and, since that date, have frequently corresponded with him on a wide array of grazing management and greenhouse gas issues. After rereading the MSU study to write this blog post, I emailed Jason to verify whether or not his research team compared their GFB survey to any CFB beef samples using the same cuts of beef with the same sampling and testing procedures. They hadn’t. Though Jason mentioned that they were going to redo the same trial, this time with samples from feedlot finished cattle CFB using the same sampling and testing methods.

So, somewhat rhetorically, I also asked Jason whether or not it was a valid exercise to compare the range and mean averages for nutrients from their 2019 MSU paper for GFB to the USDA FoodData Central nutrient database for CFB for the same cut of beef? Jason concurred with what I suggested, and that was making such a comparison was problematic particularly given the disparities between different GFB studies with the total FA’s noted above. Different sampling and testing protocols will give different results even if all the other variables are the same. What exactly were USDA’s sampling and testing protocols, and how did these methods differ from MSU’s procedures? Hard to tell from simply going to the USDA Food Data Central website. One thing noted is that the USDA only excludes inedible parts of the product that they’re testing. This criteria wouldn’t necessarily exclude the “pockets of intramuscular fat” that were avoided in the samples prepared for MSU’s tests.

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Therefore, to cut to the chase, without standardized sampling and testing methods, comparing findings from different studies or to databases is a flawed process that won’t provide any reliable results. Therefore to truly compare different GFB to other GFB as well as to CFB, all the sampling and testing procedures have to be the same. Otherwise, proverbially, apples are being compared to oranges rather than to other apples.

But then where does that leave any nutritional comparison between GFB versus CFB? Are both broad categories of beef nutritious? Yes, both are excellent sources of nutrient dense protein as well as bio-available minerals. Are either GFB or CFB good sources for pre-formed DHA Omega 3 fats? Nope, eat salmon, black cod, shellfish and or other fatty fish instead. Is GFB more nutritious than CFB? Yes….and no. Or, in other words, it depends on a wide array of variables including all of those variables noted above. For example, total fatty acid content of GFB may be similar or less than CFB depending on what feed, where, and how well the head of beef cattle is finished.  The more skillfully the steer or heifer is finished on diverse healthy pastures, the more likely the higher the FA, mineral, and phytonutrient content of the beef will be. Though like with any other hypothesis or claim, more research is necessary to substantiate that claim or back up that hypothesis. Jason and the research team at MSU are in the process of doing such research with the additional trials already noted and more scheduled for next year so that they have a lot more data all derived using the same set of analytical tools. Dr. Fred Provenza and researchers at Duke University are also doing additional research some of which is described in the video above. If standard sampling and testing protocols could be established between these studies or by an independent lab, that would go a long way to better understand how differences in grazing management, finishing, soil and plant health, etc. all affect the nutritional content of the beef that we eat.

Until then, this prolix explanation above may only further confuse some people, especially those who like to reduce everything to binary and opposing categories of red versus blue, right versus left, and GFB versus CFB. Though a less dualistic more postmodern perspective on beef production also affords a lot of opportunities for consumers to reconnect to where their food comes from and for ranchers doing direct sales to differentiate their beef products from other producers and more conventional distributors. So buying beef is no longer simply going into grocery store and reading labels that may or may not mean anything. Buying beef, as well as other meats, means knowing your producers and their production methods by visiting their ranches, farms, websites and or social media sites. If consumers want a better food system, they need to become more engaged and active participants.

Another side to this discussion is the use of growth hormone implants and sub-therapeutic levels of antibiotics in feedlot production. Even though the FDA recently restricted the use of antibiotics to stimulate growth, sub-therapeutic levels of antibiotics of hormones are still given to beef cattle in feedlots to prevent diseases and sickness including respiratory diseases and acidosis. This sub-therapeutic use “coincidentally” also stimulates daily weight gains. Previously I researched how withdrawal times and tolerance levels for antibiotics were determined and couldn’t find any clear answers. Withdrawal times are the times required that cattle have to be taken off of antibiotics before they can be slaughtered. Despite withdrawal times, after slaughter beef cattle given antibiotics are allowed to have certain “tolerance” levels of antibiotics still be allowed in their meats and fats.  Now whether these tolerance levels of antibiotics, when consumed, impact one’s gut flora or not, I’ve yet to find any definitive research on this topic. So, here too, more research is needed.

Additionally, as recently reported in the San Francisco Chronicle, rancher Bill Niman, the owner of BN Ranch and the original founder of Niman Ranch teamed up with a new company called FoodID. This company has developed a new quick way to test meats for antibiotic residues. They’ve created a QR code labeling system that consumers can use to find out this company’s test results.  According to Niman and other company officers, this labeling systems will help consumers understand what “antibiotic-free” labels truly mean as well as hopefully help reduce antibiotic use in the livestock sector.

I will go into this issue of sub-therapeutic antibiotic use more in the second part of this blog on production differences between GFB and CFB. This will occur hopefully after I have another opportunity to correspond with Bill Niman directly, who I’ve corresponded with a number of times before.

 

 

 

 

 

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