Scientists say modern farming methods and climate change have made modern produce and grains less nutritious

The advent of modern farming methods has caused fruits, vegetables and grains become less nutritious over the past 70 years, Stacey Colino reports for National Geographic. Multiple scientific studies show that many current crops have "less protein, calcium, phosphorus, iron, riboflavin, and vitamin C than those that were grown decades ago," Colino writes.

Climate change and rising carbon-dioxide levels are partly to blame, but the biggest problem is "modern agricultural processes that increase crop yields but disturb soil health," Colino reports. "These include irrigation, fertilization, and harvesting methods that also disrupt essential interactions between plants and soil fungi, which reduces absorption of nutrients from the soil."

Nutritional decline could make it harder for people to get the nutrients they need to fight off chronic illnesses, said David R. Montgomery, a professor of geomorphology at the University of Washington and co-author with Anne Biklé of What Your Food Ate. It's increasingly important to grow nutritionally dense foods, he told Colino: "We can’t afford to lose arable land as population grows. We need to prevent further damage and work to restore fertility to already degraded lands."

Montgomery and other experts still encourage people to eat more fresh produce and less-processed foods, but told Colino they hope this knowledge will inspire more people to care about how their food is grown.