November 29, 2021

Improving soil health, plant diversity can impact nutrients in food

MADISON, Wis. — A great biodiversity in ecosystems exists in nature.

“There’s no monoculture in nature — that’s man-made,” said Stephan van Vliet, nutrition scientist and metabolomics expert in the Center for Human Nutrition Studies at Utah State University.

“Oftentimes there’s a wide variety of plants and animals in nature, but humans simplify it to a single species of crops or animals and as a result require considerable fossil fuel inputs,” said van Vliet during a Grassland 2.0 digital dialogue.

“Simplified systems are typically productive in the short run, but make it difficult for farming systems to recycle nutrients and be sustainable in the long run.”

One of van Vliet’s concerns is the dependence on fossil fuels in agriculture to produce food.

“A paper that came out in 2020 reported that to produce one calorie of food it requires two calories of fossil fuels for the machinery to plant, irrigate and harvest and to produce fertilizers and chemicals to grow and protect these crops,” van Vliet said.

“It also requires another eight to 12 calories equivalence of energy to process, package, deliver and store food,” he said. “So, we need to make some changes moving forward.”

There is an increase in consumer and farmer interest in pasture-based meat and milk.

“The retail sales of U.S. grass-fed beef has doubled every year since 2012 and the global organic dairy market is also on the rise,” van Vliet said.

“Farmers are taking it one step beyond pasture raised to regenerative agriculture with systems that improve soil health and plant diversity,” he said.

“I got interested in linking the fields of food production agriculture with human health because most of the diseases of dietary origin can be traced back to diets, so the focus is building health from the ground up,” he said.

The scientist talked about a project that evaluated regenerative farming systems by collecting soil samples from pastures and neighboring cornfields. Additional samples were collected including plant samples, grain samples and grass-fed meat samples.

“We compared them using metabolomics,” van Vliet said. “We take biological samples, identify a wide variety of metabolites and group them into classes such as phenols, fatty acids or amino acids.”

Food metabolomics goes beyond protein, vitamins, minerals and fatty acids, van Vliet said.

“Typically for a nutritional panel on food you see about 13 nutrients, but food are much more complex than that,” he said. “We routinely track 150 components, but there are thousands of metabolites.”

People do not consume nutrients. They consume foods.

“Metabolites are small molecules from the breakdown of foods, drugs, chemicals or our own tissues,” van Vliet said. “A breakdown of your muscle tissue might generate amino acids.”

Animals can eat vegetation that humans cannot.

“Plants respond biochemically to sunlight, moisture and nutrients by producing phytochemicals and there can be thousands to hundreds of thousands of compounds,” van Vliet said.

“We’re really scratching the surface on the understanding on how these compounds impact our health,” he said. “Research suggests phytochemicals are potentially anti-inflammatory, anti-bacterial and antioxidant at moderate doses, but we also know at high doses some of these can become problematic.”

Grass-fed beef is not all the same, van Vliet said.

“When animals are finished on diverse plant species pastures, we see this translate into the most phytochemical rich meat and milk,” he said. “It is reduced on monoculture pastures and lower or sometimes undetectable when animals are feedlot finished on concentrates.”

Grass-fed meat and dairy have been studied for inflammatory response, van Vliet said.

“Inflammation plays a central role in metabolic diseases such as heart attack and stroke, but also a central role in cancer, diabetes and arthritis,” van Vliet said.

“Every time we eat, we have an inflammatory response, but if the inflammatory response to food becomes elevated and turns into a low-grade systemic inflammation, that’s when we run into trouble and increase our risk of metabolic disease,” he said.

“Research is sparse, but studies show a potential for anti-inflammatory effects,” van Vliet said.

“Current knowledge does not allow for direct linking of livestock production practices, so we need more human data on this topic,” he said. “But I feel comfortable saying biodiverse pasture-raised meat and milk does look healthier on paper.”

For more information about Grassland 2.0, go to www.grasslandag.org.

Martha Blum

Martha Blum

Field Editor