A Nutrition-Depletion Dilemma

"Every leaf and every grass blade on earth makes more and more sugars as CO2 levels keep rising." "We are witnessing the greatest injection of carbohydrates into the biosphere in human history -- an injection that dilutes other nutrients in our food supply."
"What struck me [on the publication of his first paper] is that its application [modelling the relationship between a food source and a grazer] is wider [What about the nutrients people receive?]."
"It was kind of a watershed moment for me when I started thinking about human nutrition."
Irakli Loladze, Mathematical Biologist & Quantitative Ecologist, USA , Bryan College of Health Sciences, Lincoln

Loladze found that plants are getting too much carbon dioxide, which is resulting in decreased nutrition in our food supply as a rise in carbohydrates is diluting other nutrients. Getty Images

"Loladze and a handful of other scientists have come to suspect that's not the whole story [breeding practices of yield over nutrition] and that the atmosphere itself may be changing the food we eat."
"To say that it's little known that key crops are getting less nutrition due to rising CO2 is an understatement."
"It is simply not discussed in the agriculture, public health, or nutrition communities. At all."
Helena Bottemiller Evich, Politico

Increasing carbon dioxide in the atmosphere is reducing the protein in staple crops like rice, wheat, barley and potatoes, raising unknown risks to human health in the future. | Getty Images

"It’s really interesting, and you’re right, it’s not on many people’s radar."
"We don't know what a minor shift in the carbohydrate ratio in the diet is ultimately going to do [noting that the overall trend toward more starch and carbohydrate consumption has been associated with an increase in diet-related disease like obesity and diabetes]."
"To what degree would a shift in the food system contribute to that? We can't really say.”
Robin Foroutan, integrative medicine nutritionist

These are the scientists whose research leads them to believe that there is evidence to acknowledge that climate change is having its impact on the world's major edible agricultural crops upon which we rely; staples such as coffee, corn, rice, soybeans and wheat. Leading to suspicions that other deleterious effects of a changing climate are also taking place which science simply hasn't yet discovered, all of which alter the quality of the food we eat and depend upon for the vital intake of minerals and vitamins.

According to Dr. Loladze, rising levels of carbon dioxide (CO2) in Earth's atmosphere are impacting agricultural plants, leading to degradation of quality and a decline in their nutritional value. With the increase of CO2 prevalent in the atmosphere, nutrients have given way to sugars, an exchange that devalues the food we eat and leaves us short of critical iron, protein and zinc. Previous research on agricultural yields and quality have demonstrated the declining nutritional value of garden crops.

Less vitamin C, calcium, iron and additional nutrients available for humans when they consume fruits and vegetables; measurements that have been verified since 1950. In 2002 the journal Trends in Ecology and Evolution published Dr. Loladze's first research paper on the "junk-food effect" of increasing CO2 resulting in diminishing nutrition to be had from plants. Twelve years later, another paper focusing on the same theme, representing 15 years of research, was published, despite which not much attention is being turned on the issue.

There are, of course, always other explanations. That plant biologists are always looking for new and improved products; that can ship to distant markets without bruising, for example, or strains that are capable of producing better taste (i.e. sweetness) or more pleasing forms of the fruits and vegetables; shoppers are notoriously picky about fruits and vegetables whose shapes are less than perfect. Agricultural practices also come under scrutiny; when one type of crop is planted in the same area year after year certain soil nutrients identified with that crop may be depleted.

If it is indeed climate change that is responsible in large part for diminished vitamins and minerals in our plant food, and not cultivation methods, agricultural science may find a way to compensate, but it represents a dilemma of gigantic proportions. On the other hand, if it is a matter of soil depletion that other scientists seem to point at, the remedy may be far more accessible; rotation of crops, and rest periods for soil identified as diminished in quality from overuse.

There is nothing new about soil depletion. What we think of as primitive societies knew enough to rotate crops. They also renewed the soil by giving it periods of rest from one year to another. And used the method of burning over crop remnants left in the field, and the carbonized remnants enriched the soil, returning it to a state of nutrient replenishment. 

"It would be overkill to say that the carrot you eat today has very little nutrition in it—especially compared to some of the other less healthy foods you likely also eat—but it is true that fruits and vegetables grown decades ago were much richer in vitamins and minerals than the varieties most of us get today. The main culprit in this disturbing nutritional trend is soil depletion: Modern intensive agricultural methods have stripped increasing amounts of nutrients from the soil in which the food we eat grows. Sadly, each successive generation of fast-growing, pest-resistant carrot is truly less good for you than the one before."
"A landmark study on the topic by Donald Davis and his team of researchers from the University of Texas (UT) at Austin’s Department of Chemistry and Biochemistry was published in December 2004 in the Journal of the American College of Nutrition. They studied U.S. Department of Agriculture nutritional data from both 1950 and 1999 for 43 different vegetables and fruits, finding “reliable declines” in the amount of protein, calcium, phosphorus, iron, riboflavin (vitamin B2) and vitamin C over the past half century. Davis and his colleagues chalk up this declining nutritional content to the preponderance of agricultural practices designed to improve traits (size, growth rate, pest resistance) other than nutrition."
Scientific American

Credit: Martin Poole, Digital Vision/Thinkstock