How Climate Change Could Be Affecting Nutrition

It is no secret that many, if not most, Americans fail to eat enough fruits and vegetables, which can lead to deficiencies in basic nutrients. But levels of consumption of these important foods is only part of the problem: Studies indicate that they are not as nutrient-dense as they once were. At the Institute for Functional Medicine's 2020 Annual International Conference, scientists warned that nutrient density in crops has declined, including important micronutrients such as magnesium, zinc, iodine, iron, and folate.

Climate change and other factors, such as topsoil erosion, land-management practices, and agricultural methods, affect availability of food crops and potentially impact their associated nutrient levels. An analysis of National Health and Nutrition Examination Surveys suggests that an estimated 31% of Americans are at risk of developing micronutrient malnutrition.

The connection between climate change and declines in plant mineral composition is not completely understood. Some argue that the increased atmospheric carbon dioxide (eCO2) brought on by climate change potentially enhances overall crop yield, which may be a benefit in some situations, even if the mineral quality of the crop is decreased.

Experts believe much of the focus should be down in the dirt. Maintaining a diverse soil biota is essential for agricultural sustainability for both productive and nutrient-dense crop yields. In 2016, a government report on US soils suggested that land-use changes in the past 50 years have contributed to reduced ecosystem functions.

An estimated 31% of Americans are at risk of developing micronutrient malnutrition.

The human body requires certain levels of micronutrients for normal functioning.  Deficiencies in one or more micronutrients may be a detriment to health and lead to chronic disease. These issues of deficiency and malnutrition could be happening on a global scale, as well right in our own backyard. Micronutrient malnutrition has been associated with a wide range of physiological impairments, including metabolic disorders; reduced immune, endocrine, and cognitive function; and delayed or inadequate physical development.

The research is not entirely clear-cut, however. A 2018 meta-analysis that used 57 articles consisting of more than 1,000 observations found that eCO2 increased the concentrations of sugars, antioxidant capacity, phenols, flavonoids, ascorbic acid, and calcium in the edible part of vegetables, but decreased the concentrations of protein, nitrate, magnesium, iron, and zinc. So, it may be true that we are consuming higher levels of macronutrients at the expense of crucial micronutrients; it is an ongoing debate.

From a functional medicine standpoint, micronutrient deficiencies may not be immediately obvious. A nutrition-oriented physical exam, including food diaries, can help evaluate the variety of food choices, and may help inform treatment strategy. Any decline of essential micronutrients in food crops is important to consider for the potential prevention of health issues, including chronic diseases, as well as for the promotion of optimal health for patients.