For many Asian populations, rice has been a dietary staple for thousands of years. It’s estimated that around 600 million people in some countries, including Cambodia, Indonesia and Bangladesh get over half of their daily calorie and protein intake from rice. In recent years, this has been the case in many parts of Africa as well, making rice an essential food in many countries across the world.
But, a recent study carried out by a team of scientists has shown that as carbon dioxide levels in the atmosphere continue to rise, there’s a real risk that the nutritional value that rice offers could drastically reduce. Carbon dioxide levels are now at their highest level ever recorded. Data from last month shows that levels were at an average of 410 pppm. This is the highest we’ve seen in the last 800,000 years.
The level of emissions is predicted to increase further in the coming decades. With this in mind, experts are now warning that these rising levels of carbon dioxide could have serious health implications, especially for the two billion people across the world who are relying on rice as their main source of food.
This study is the first published evidence that too much carbon dioxide in the atmosphere could affect the levels of B Vitamins in rice. This is particularly true for vitamin B9 (folate), for which the study showed there was a 30% decline in the levels of the nutrient. Reduced levels of vitamin B9 is especially important for pregnant women as it reduces the risks of birth defects. The study also found that there was an average 10% reduction in protein and iron, and a 5% reduction in the levels of zinc.
When commenting on the new evidence, Professor Kazuhiko Kobayashi of the University of Tokyo said: “Rice is not just a major source of calories, but also proteins and vitamins for many people in developing countries and for poorer communities within developed countries.” Coauthor Professor Kristie Ebi from the University of Washington added: “Reductions in the nutritional quality of rice could affect maternal and child health for millions of people.”
Dr Lewis Ziska, a plant physiologist at the US Department of Agriculture, who co-authored the new study said: “People say more carbon dioxide is plant food – and it is. But how plants respond to that sudden increase in food will impact human health as well, from nutritional deficits to ethnopharmacology to seasonal pollen allergies – in ways that we don’t yet understand.”
Whilst it’s still unclear what the exact effects would be of these populations consuming rice with lower levels of nutrients, the scientist who were involved in the stud predicted that it could pose major health risks including stunted growth and an increased risk of diseases. These effects would be much more prevalent in poorer communities who rely on rice for a larger proportion of their nutrients.