How a Changing Climate Impacts the Nutritional Value of Food

We often think of climate change solely in terms of influencing the weather and the environment. We may also link climate change with reduced food production due to drought and adverse weather. But we are also now learning that climate change will have a profound and negative impact on food quality and nutrient content not just quantity.

Climate change refers to overall climatic changes that take place over a long period of time. This can include temperature, precipitation, and wind. Global warming on the other hand only pertains to hotter temperatures caused by increased manmade greenhouse gases released into the atmosphere—in particular carbon dioxide (CO₂), Nitrogen oxides (NO_x) and methane (CH₄)

According to the The Intergovernmental Panel on Climate Change, in 2014 it was estimated that global food production will decrease by 2% per decade while demand will increase by 14%. At the same time, compelling research indicates that the nutrient content of food will also decline. While much has been written about food quantity as it relates to climate change, we are only now hearing about the food quality issue.

This means that your health, and that of the soil, plants and animals is inextricably linked to climate change.

Declining Food Quality

Before 2015, studies to gauge the impact of increased CO₂ levels on the nutrient content of foods used artificial growing conditions that emulated what is predicted for the middle of this century. But new research technology known as free-air CO₂ enrichment (FACE) allows for crops to be exposed to ambient and elevated CO₂ in normal field conditions. This new technology provides an even more accurate assessment of the CO₂ impact on food quality.

A 2015 paper published in Scientific Data that used the FACE technology collected data across three continents: this represented more than 10 times the data from previously published studies and found that elevated CO₂ led to a decrease in zinc, iron, and sometimes protein concentrations in various foods.

Whilst it’s true that CO₂ actually stimulates plant photosynthesis and growth, which can positively impact food production; research now shows that increased CO2 creates plants with higher carbohydrate concentrations and reductions in protein and mineral content.

According to a 2018 paper reduced zinc and iron concentrations in food could lead to “a greater burden of infectious diseases, diarrhoea, and anaemia.” Another paper in 2018 that used FACE technology to evaluate rice—a primary food source for more than 2 billion people worldwide found in addition to declines in protein, iron, and zinc there were also declines in vitamins B1, B2, B5, and B9.

Declines in food quality also negatively impact food quantity. A 2019 paper showed similar nutrient declines in grains of non-legume crops. This paper also found lower harvest yields in the foods lacking these key nutrients. The researchers concluded that

“low nutrient concentrations in grains also constrain seed germination and seedling establishment, leading to lower yields at harvest. A number of studies have demonstrated that seed nutrient concentrations can strongly affect seedling vigour and development.”

A 2018 meta-analysis of 57 articles looking at elevated CO₂ and the nutritional content of vegetables found decreased concentrations of protein, zinc, and iron, as well as magnesium. Similar to other research, this analysis showed that there was also an increase in carbohydrates such as glucose, fructose, and sucrose with these altered environmental conditions. Several researchers have speculated that these changes, in particular the protein to carbohydrate ratio caused by elevated CO₂ could worsen an already out of control global obesity epidemic.

The human race relies on the nutrient content of food to help fend off illness and achieve optimal wellness. The obvious concern is that such significant declines in key nutrients will lead to increased micronutrient deficiencies that will lead to increased illness.

In an article published on the Our World Data website, Ritchie and Roser explain that there are 3 key strategies that can be employed to help address existing and expected micronutrient deficiencies:

1. Supplementation
2. Food fortification
3. Biofortification (the increasing of nutrients in soils)

The authors of a paper published in the journal Nature Climate Change also agree that supplementation, fortification, and biofortification are solid strategies to help ameliorate the possibility of dangerous levels of micronutrient deficiency around the world. The authors conclude;

“Many people around the world rely on vegetal sources for nutrients that are critical to their health and are likely to suffer nutritional insufficiency in the coming decades as those food crops become nutritionally impoverished as a result of anthropogenic CO₂ emissions.”

The scientific evidence now strongly suggests that increasing CO₂ levels can negatively impact the nutrient quality of many foods and when nutritional value declines, micronutrient deficiencies increase.

Along with those deficiencies comes a long list of symptoms and corresponding illnesses such as anaemia, cognitive decline, birth defects, osteoporosis, cardiovascular disease, and many non-communicable diseases.

Obviously, something needs to be done. And perhaps the best place to start is to replace carbon and nutrients in soils, enhance the soils microbiome via prebiotic (using soluble organic compounds) and exogenous supplementation of the soils with bio-available macro and micronutrients to enable plants to increase nutrient density.

Supplementation with essential nutrients, fatty acids and bacteria are also well understood to mitigate ingested related deficiencies, genetic determined needs for increased intake and age, mass and activity related deficiencies – it appears we must also consider climate induced nutrient shortages also.

Way back in the 1940s in the book ‘An Agricultural Testament’ the author Sir Albert Howard stated that;

“the failure to maintain a healthy agriculture has largely cancelled out all of the advantages we have gained from our improvements in hygiene, in housing and our medical discoveries”.

It’s time to keep in mind that current agricultural practices do not support global nutrient retention and remain primarily exploitative not regenerative. Oral supplementation will be a mainstay of clinical care until such time as there is a change to the way soils, their microbiome and nutrient replenishment practices are reflected in increased plant nutrient density.