Using metabolomics to look at finished beef

by Sonja Heyck-Merlin

“Oftentimes, we hear that there is a relationship that healthy soils equals healthy plants equals healthy humans or animals. While that intuitively makes sense, and there’s certainly pockets of literature in their respective fields to suggest that is the case, there has been a lack of systems research that tries to tie it all together,” said Dr. Stephan van Vliet at the 2022 New England Pasture Consortium annual meeting. Van Vliet is an assistant professor at the Center for Nutrition Studies at Utah State University.

“I have a particular interest in systems research and understanding linkages between plant, animal and human health and even soil health,” he added.

One of van Vliet’s research projects focused on comparing nutrient density of meat from two different livestock systems: beef finished on a corn-based total mixed ration and beef finished on biodiverse pastures. The research was funded by a Sustainable Agriculture Research and Education grant titled “Southern Pasture-Raised Beef: From Farm to Table to Us.” Collaborators were the Duke University School of Medicine, North Carolina State University and Utah State.

The research involved collecting soil, forages and meat (ground beef) from the two farms. He then profiled several hundreds of nutrients from the samples using a mass spectrometer, which simultaneously measures a large number of unique compounds in foods. Each compound is referred to as a metabolite and this research technique is called metabolomics. Next, he analyzed the data with specialized computer software to examine if there was a relationship between the nutrients of the soil, the plants and the animals.

According to van Vliet, humans tend to simplify things, including agricultural systems, which often include only a single species of plant requiring significant external inputs. In contrast, pasture-based systems involve greater biodiversity and the recycling of nutrients. His interest in the sustainability of pasture-based systems, combined with his quest to scientifically understand the role of red meat in human health, drives van Vliet’s research. “Essentially, we’re getting after the very simple question: Do more sustainable practices improve health along a continuum all the way up to human health?” he said.

Dr. Stephan van Vliet

The connection between grazing and higher omega-3 fatty acids is well established. Oftentimes, van Vliet said, it’s thought that this is the only difference between grain-fed and grass-fed meat. The food matrix, however, contains hundreds of bioactive compounds that can potentially impact human health. This research project involved 500 metabolites, but the top 30 ranking biochemicals that separated grass- and grain-fed beef were vitamin metabolites, phytochemical metabolites and lipid metabolites.

In terms of vitamins, one of the research findings was that niacin, the main form of vitamin B3 in foods, was nine-fold higher in grass-fed beef. Niacin is known to help promote healthy nervous and digestive systems and healthy skin.

Phytochemical metabolites were also higher in the grass-fed meat. Phytochemicals are plant-derived compounds. “The phytochemicals are picked up from forage and directly transferred into the meat and milk of animals,” van Vliet said. According to van Vliet, phytochemicals are potentially anti-inflammatory, antibacterial, antioxidant and some work suggests they may help with the management of chronic disease. He said, however, that future work is needed to determine if the presence of these compounds in grass-fed beef has an appreciable impact on human health.

In his lipid analysis, van Vliet found that various long-chain saturated fatty acids were enriched in grass-fed beef. These fatty acids, unlike most saturated fats, are associated with a decreased risk of heart disease and cancer, according to van Vliet. His work also found beneficial effects on metabolic health of animals, as the grass-fed animals had improved mitochondrial function (meaning more energy created in the cells).

Van Vliet stressed that the data do not indicate that grain-finished beef is unhealthy; it’s simply indicative that additional health-promoting compounds are accumulated in animals finished on biodiverse pastures. Furthermore, feeding a more phytochemically-rich forage, such as alfalfa, in feedlot systems can help reduce the gap of these compounds that exists between grain- and grass-finished livestock.

“To simplify, what we typically see in our work so far is that the nutrient density of meat is improved when animals have access to biodiverse and phytochemically-rich forage,” van Vliet said.

Testing of these metabolites is available through the Beef Nutrient Density Project, which is a collaboration with the Bionutrient Institute. Van Vliet encourages farmers who want their soil, plants and beef tested to sign up at bionutrientinstitute.org/beef.

“It will give farmers more insight into how their production practices impact beef nutrient density, and it will help the scientific field to better understand the relationship between various ecoregions and production systems and how they impact beef quality and nutrition,” van Vliet said.