Humans Possess Surprising Nutritional Intelligence
Pioneering research has shed new light on what drives people’s basic food preferences, indicating our choices may be smarter than previously thought and influenced by the specific nutrients we need — as opposed to just calories.
The international study, led by the University of Bristol (UK), set out to test the widely held view that humans evolved to favor energy-dense foods and that our diets may be balanced simply by eating a variety of different foods. Contrary to this belief, the study revealed that people seem to have “nutritional wisdom,” whereby foods are selected in part to meet our need for vitamins and minerals and to avoid nutritional deficiencies.
The paper, published in the journal Appetite, gives renewed weight to bold research carried out in the 1930s by an American pediatrician, Dr. Clara Davis, who put a group of 15 babies on a diet that allowed them to “self-select” — in other words, to eat whatever they wanted — from 33 different food items. While no child ate the same combination of foods, they all achieved and maintained a good state of health, which was taken as evidence of “nutritional wisdom.”
Its findings were later scrutinized and criticized, but replicating Davis’ research was not possible because this form of experimentation on babies would today be considered unethical. As a result, it has been nearly a century since any scientist has attempted to find evidence for nutritional wisdom in humans — a faculty that has been found in other animals, such as sheep and rodents.
To overcome these barriers, the team developed a novel technique that involved measuring preference by showing people images of different fruit and vegetable pairings so their choices could be analyzed without putting their health or wellbeing at risk.
In total, 128 adults participated in two experiments. The first study showed that people prefer certain food combinations more than others. For example, apple and banana might be chosen slightly more often than apple and blackberries. Remarkably, these preferences appear to be predicted by the amounts of micronutrients in a pair and whether their combination provides a balance of different micronutrients. To confirm this, the team ran a second experiment with different foods and ruled out other explanations.
To complement and cross-check these findings, real-world meal combinations as reported in the U.K.’s National Diet and Nutrition Survey were studied. These data demonstrated that people combine meals in a way that increases exposure to micronutrients in their diet. Specifically, components of popular U.K. meals — for example, “fish and chips” or “curry and rice” — seem to offer a wider range of micronutrients than meal combinations generated randomly, such as “chips and curry.”
The study’s co-author is Mark Schatzker, a journalist and author of The Dorito Effect, who is also the writer-in-residence at the Modern Diet and Physiology Research Center, affiliated with Yale University. Schatzker noted that “The research throws up important questions, especially in the modern food environment. For example, does our cultural fixation with fad diets, which limit or forbid consumption of certain types of foods, disrupt or disturb this dietary ‘intelligence’ in ways we do not understand?
“Studies have shown animals use flavor as a guide to the vitamins and minerals they require. If flavor serves a similar role for humans, then we may be imbuing junk foods such as potato chips and fizzy drinks with a false ‘sheen’ of nutrition by adding flavorings to them. In other words, the food industry may be turning our nutritional wisdom against us, making us eat food we would normally avoid and thus contributing to the obesity epidemic.”
| How does this knowledge affect farmers? From Kathleen DiChiara: An estimated three billion people from both developed and developing nations have specific nutrient deficiencies. In the U.S. and other developed countries, poor nutrition results in higher rates of infection, increased risks of all types of cancer and an increased risk of obesity. This strain on our health, our economy and our happiness is real. One of the key drivers for consumers purchasing food is taste. The food industry’s biggest obstacle is still the simple fact that people won’t buy what doesn’t taste good. While taste and smell may seem closely related, they are in fact separate. Receptors on the taste buds of your tongue pick up taste, which comes in five distinct categories: sweet, sour, salty, bitter or umami (savory). Aroma is picked up when volatile chemicals are released into the air or picked up from the back of the mouth into the nose. This close link makes it easy to confuse aroma for taste. Beyond the mouth, we have taste receptors throughout the body. Bitter receptors can be found in the lining of the esophagus, stomach, intestines, liver, pancreas and gallbladder, as well as the respiratory and nasal tracts. Scientists believe that when we are exposed to potentially harmful bacteria and viruses, certain bitter receptors are activated in our mouths and noses, which launch an immune response in the respiratory system. Perhaps Mother Nature has encoded our food with the nutritional data we need to exercise and maintain systemic resilience. You may be surprised to know that scientists and food companies are exploring ways to use smells — to trick our brains into thinking food contains sweetness and saltiness, even when it doesn’t. This is known as “phantom aromas. ”It makes you wonder if tasting a flavor that doesn’t exist has health consequences. If the taste and aromas are “manufactured” in foods we consume and don’t come with the broad-spectrum, complementary cargo on board that Mother Nature intended — antioxidants, antivirals, fiber, phytonutrients, enzymes, beneficial microbes and more — we may be left overfed and undernourished, and potentially chronically ill. But farmers have an advantage that flavor scientists will never be able to compete with: the complex nutritional intelligence within food that accompanies the naturally occurring flavor of each ingredient. Most people want to eat healthier. Research supports emphasizing taste, and positive experience could help shift dietary habits. It may be time to expand our language of food and stimulate some appetites in favor of nutritional wisdom. |
Soil Networks Become More Connected and Take Up More Carbon as Nature Restoration Progresses
Soil organisms have an important role in aboveground community dynamics and ecosystem functioning in terrestrial ecosystems. However, little is known about entire soil networks.
A study published in Nature Communications shows that during the course of nature restoration on abandoned arable land, a compositional shift in soil biota — preceded by tightening of the belowground networks — corresponds with enhanced efficiency of carbon uptake. In mid- and long-term abandoned field soil, carbon uptake by fungi increases without an increase in fungal biomass or a shift in bacterial-to-fungal ratio.
A diagram in the study visually depicts the strength of interrelationships between bacterial and fungal groups and other organisms. The number of lines linking different organisms in fields that have remained wild for longer times are far more numerous than those linking species in recently abandoned fields.
The implication of this study is that during nature restoration, the efficiency of nutrient cycling and carbon uptake can increase by a shift in fungal composition and/or fungal activity.
| What does this mean for growers? From Dr. Robert Kremer: This study by Morriën et al. offers new information on how soil food webs (SFWs) develop in fields during transition from previous intensive cultivation to conversion toward a more natural state of perennial vegetation. The authors report during the “nature restoration” on several fields studied in the Netherlands that soil fungal components, including mycorrhizae, increased their efficiency in C uptake, but this was not due to C inputs by plant roots. Simultaneously, predatory components of the SFW — including nematodes, mites and Collembola — increased, resulting in C released as they consumed bacterial and fungal prey, which apparently was metabolized preferentially by fungi. An unexpected finding was that despite fungi dominating C uptake in the SFW, no increase in fungal-to-bacterial ratio (F:B) was detected. Ecological agricultural farmers often consider F:B an important indicator of ecosystem functioning and recognize that higher values reflect optimum soil health properties, including C cycling, decomposition and storage, and soil structure. However this study suggests that F:B values may be influenced by the efficiency of C metabolism and microbial uptake in the SFW. Unfortunately, no indicator of metabolic activity such as CO2 respiration was presented to confirm C uptake efficiency by fungi. Although this study presents new and interesting soil health information based on SFW interaction analyses, astute ecological farmers should consider the context of this information and realize it may not apply to their particular farming system. Soils at all study sites were sandy texture and the successional grassland was a mixture of two cool-season grasses (bent grass and tufted grass) and a plantain species. Actual values of soil chemical and physical properties were not presented, only shown in correlation analyses. Thus, the study was limited to a soil type that likely lacked good aggregation and we have little notion of reference values on soil organic matter, pH, etc. — all important in understanding the SFW environment. Furthermore, the grassland was mowed and grazed annually, which does not represent a “natural landscape.” This management would obviously affect C inputs by the vegetation (i.e., root exudation), as well as the overall SFW composition, and confounds the findings of the study. Many other factors affecting the study outcomes, such as the level of mycorrhizal infection/colonization of the plant components, are too numerous to detail given the space for this commentary. In summary, the study is important to growers because it demonstrates the dynamic and potential variations in SFW functions; however, one also should be aware that variations in microbial C uptake and F:B are likely not constant across all agro-ecological systems, and considerable future, well-designed research on contrasting systems are needed to fully show that such possibilities may apply to their particular situation. |
Virus Tricks Caterpillars into Climbing by Altering Their Vision
Baculoviruses can induce climbing behavior in their caterpillar hosts to ensure that the caterpillars die at elevated positions on plants. This improves the probability of virus transmission, since it enhances the ability of the virus to spread over the adjacent foliage.
A team of researchers from China Agricultural University has recently discovered how this happens: the virus changes the expression of genes associated with the insect’s visual system, particularly the genes that perceive light. The findings were recently reported in Molecular Ecology.
The team infected a species of cotton bollworm larvae with a virus called nucleopolyhedrovirus (NPV) and set placed them near plants with lights at different heights. For the systems with higher lights, infected larvae tended to climb much higher before dying. They also died closer to the lights — no matter the height of the lights.
The scientists hypothesized that the virus was altering the visual signaling pathway of their hosts. They confirmed this by analyzing the genomes of healthy and infected larvae and identified between 2,700 and 3,500 genes that differed between the groups. From these they found three that were significantly upregulated after the viral infection, each of which was related to light detection.
Finally, the team genetically modified larvae using CRISPR/Cas9 to lack each of these three genes; the resulting larvae lacked the ability to respond to light and died at a lower height when infected compared to a control group.
The method the virus uses to alter the genes remains a mystery — one of the many examples of the extreme complexity of the natural world.
Non-Profit Support for Cover Crops
The National Fish and Wildlife Foundation recently announced $2.6 million in grants to enable Midwest farmers to establish cover crops on over 500,000 acres.
The Midwest Cover Crop Initiative is a public-private partnership that accelerates large-scale, voluntary adoption of cover crops across several midwestern states. The initiative awards grants to provide outreach and technical assistance and to facilitate multi-year financial assistance contracts with farmers. Through this support, the initiative aims to enhance soil health, reduce atmospheric greenhouse gases and improve water and wildlife resources while providing economic benefits to participating farmers.
Cover crops are grown between harvested crops to protect soil from erosion, store nutrients, increase water infiltration and improve soil structure. The conservation impact of cover cropping systems is significant — improved water quality, reduced atmospheric greenhouse gases and even habitat benefits for pollinators or other wildlife. Farmers who implement a cover cropping system often see economic returns with reduced input costs and higher crop yields. It’s a major win-win conservation opportunity.
The Midwest Cover Crop Initiative is implemented with support from ADM and NRCS. Launched in 2022, the initiative awarded approximately $2.6 million to grants that: 1) conduct targeted outreach and provide technical assistance to farmers; 2) develop multi-year contracts with farmers for cover crop plantings; 3) coordinate ADM incentive payments to farmers and facilitate enrollment in Farm Bill cost-share programs; and 4) monitor and report environmental and economic outcomes.
Funding availability is limited to cover crops on active corn, soybean, and/or wheat production systems in Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota and Ohio, with an emphasis on projects that deliver large cover crop acreages (tens of thousands to hundreds of thousands of acres) on a cost-competitive basis.
Improving the Regenerative Supply Chain
This past Earth Day (April 22), Kocher Foods International opened Regenerative Mills, a $250,000 flour mill, in an effort to drive market expansion of regenerative agriculture.
Regenerative Mills will process gluten-free grains that come directly from regenerative farms. In turn, this flour will be used in all of their pizza crusts and products. Around the World Gourmet, also owned by Kocher Foods International, is a leading producer of gluten-free, allergen-free, plant-based, vegan pizza crusts and other products that are sold to restaurants, groceries and other locations around the United States, including Pizza Joe’s, a 42-unit chain in western Pennsylvania.
Jennifer Kocher, founder and president of Kocher Foods International, says that her mill will solve a problem in the supply chain for companies desiring clean, regenerative products. She believes that regenerative food is the next step in the future of the food industry, giving consumers a sense of connection to the foods they eat and give to their children. She also states that regenerative farming and bringing regenerative foods to market can help battle climate change, all while bringing a more nutrient-dense product to the consumer.
Kocher says that the very first flour to be made will be from both brown and white rice and expand to regeneratively grown grains including millet and sorghum, as well as vegetables such as cauliflower and mushrooms.
