About 94 percent of Americans suffer from at least one nutrient deficiency. Doctors and nutritionists often suggest adjusting our diets to include more fruits and vegetables to remedy the lack of vitamins and minerals we intake daily. But new research suggests that these essential nutrients are actually harder to come by. That's because even the healthiest vegetables and fruits no longer contain as much of the vitamins, minerals and antioxidants we need, or that they used. It all comes down to the higher carbon levels in the atmosphere.

As climate change continues and the CO2 levels increase, the nutrient content of our plant-based food will continue to diminish over time, a new study tells us. Why does this happen?One would logically think that as the ozone layer thins our plants would produce more protective compounds to stave off the harmful UV rays of the sun, and be more full of antioxidants.

While more carbon dioxide increases photosynthesis, and elevated levels of atmospheric carbon dioxide will end up producing less nutrient-rich food, according to scientists from the Institute for Plant Science of Montpellier in France. But why would more photosynthesis within plants end up producing less nutrient-dense foods? Think of it as speeding up the production line, since the plants are essentially reacting by turning up the photosynthesis within their cells, but that can mean they have less time to absorb nutrients from the soil, the water, and the air.

So climate change drives up CO2 and those higher levels of CO2 in the atmosphere lead to more active photosynthesis –– the process plants used to produce energy. This leads to increased productivity (by the plant), which can actually make it more difficult for plants to retrieve enough key minerals from the soil to produce nutritious crops.

"There are many reports in the literature showing that the CO2 levels expected at the end of the twenty-first century will lead to a lower concentration of nitrogen in most plants, mainly affecting the protein content in plant products," Alain Gojon, research director of France's National Research Institute for Agriculture, Food and the Environment, said. "It is very important to understand why growing plants at elevated CO2 has such a negative effect on the protein content of most staple crops and the future of food."

Increased Carbon Threatens Nutrient Growth

The research team examined how more active photosynthesis in plants can lead to highly competitive crops, essentially fighting with one another for the nutrients in their environment.  This can drain key minerals such as nitrogen, iron, and phosphorus from the soil. Without the proper level of these minerals in the soil, crops cannot build a full nutrient profile. In general, mineral content in soil is significantly less abundant than just a few decades ago, the scientists found, and as climate change speeds up, ever increasing productivity rates in plants will further drain the soil of necessary minerals that get passed to us when we eat these foods.

Protein Content of Food Will Get Reduced

"Two main nutrients that are essential for human nutrition may be affected by this phenomenon," Gojon said. "The first one is proteins built from nitrogen. In developing countries this can be a big issue because many diets in these countries aren't rich in proteins and plants grown in environments with elevated CO2 can have 20 to 30 percent less protein. The second nutrient that is bound to be lacking in foods grown amidst elevated CO2 levels is iron. Iron deficiency already affects an estimated two billion people worldwide.

"The terrestrial carbon sink associated with enhanced photosynthesis may be limited, adds Gojon, "if most of the vegetation is deficient in nitrogen and other minerals, which may prevent any additional increase of CO2 capture from the atmosphere."

Despite offering some benefits to crop production, the increased rate of photosynthesis could make combatting climate change even more difficult in the future. By draining the soil of its minerals, crop production will be unable to produce nutrient-dense crops humans need for food. The researchers set out to highlight how crop production is impacted by increased atmospheric carbon levels to mitigate intensified photosynthesis and crop productivity.

"We would like to really understand the mechanisms that are responsible for the negative effects of elevated CO2 on the mineral composition of plants," corresponding author Antoine Martin, researcher of the French National Centre for Scientific Research, said. "For example, we are currently exploring the natural genetic variation behind these negative effects, that could be used afterward to improve crops' nutritional value under future CO2 atmosphere."

How to Get the Most Nutrients From Your Food

Common fruits, vegetables, and grains grown today contain significantly less calcium, phosphorus, iron, riboflavin, vitamin C, and protein than crops grown 70 years ago, according to National Geographic. This trend is contributing to the growing number of Americans that experience nutrient deficiencies. As more consumers switch to plant-based diets, it is essential to understand how you can get the most nutrients from your food.

  • Don't overcook your vegetables. Be careful how you prepare your vegetables because overcooking causes several veggies such as broccoli to lose a substantial amount of their healthy nutrients, which get neutralized by steaming.
  • Buy local produce. Visit your local farmer's market or co-op to get the freshest vegetables and fruits. Less processing means more nutrients. The longer a vegetable or fruit has been off the vine, the lower its nutritional value is.
  • Freeze or can your veggies. By preserving your food, either canning it or freezing it, the fruits and vegetable keep their nutritional quality for longer. Freezing does not harm most of the compounds such as vitamins and minerals that you are trying to preserve.
  • Add healthy fats to your diet. Adding healthy fats like nuts and avocado to your salads can help you absorb several nutrients such as the vitamin K found in leafy vegetables. Make sure you know which nutrients are fat soluble and try to eat your spinach or other greens with a touch of heart-healthy oil like olive oil for best results.
  • Be aware of anti-nutrients including phytates, tannins, and oxalates. These can inhibit the absorption of essential minerals in the gut and are known as anti-nutrients because even if you eat healthy foods they can strip the benefit of the nutrients/
  • Eat plenty of vitamin C. By eating more vitamin C, you help your body absorb several nutrients at more efficient rates such as iron and folates.

Eat Plant-Based to Reduce Carbon Emissions

To help mitigate the ongoing climate crisis, introducing more plant-based foods can help protect the planet and keep the world's soil healthy. Adopting a plant-based diet can reduce greenhouse gas emissions by an estimated 61 percent. Without reducing meat and dairy production, carbon emissions will continue to increase at rapid rates, which could lead to a greater reduction in nutrients from our foods.

For more planetary news, visit The Beet's Environmental articles.

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