Does Pollution Affect Nutrition?

Until now, much of the debate surrounding the effect of climate change on food security (and vice versa) has focused on how the global phenomenon may result in food shortages, and how food processing wastewater treatment facilities can help to curb harmful effects on the environment. Less exposure has been given to how climate change and increased pollution might affect the nutritional content of food.

However, a new study from China has illustrated that rice exposed to higher concentrations of carbon dioxide (CO2) may lose much of its nutritional value. Adding to the information gathered by previous studies, which suggested increased exposure to CO2 would reduce protein, iron and zinc content of crops, the new report also revealed that essential vitamins would be in short supply in the face of rising CO2 levels.

An experimental study

The researchers behind the paper, published last month in Science Advances, wanted to determine how nutritional content of rice would be affected if current trends of carbon emissions continued throughout the century. Using the free-air CO2 enrichment technique, also known as FACE, they set up experimental paddies on China’s Yangtze River and incorporated results from a similar study conducted in Tsukuba, Japan.

In all, the report encompassed 18 different strains of rice which were exposed to concentrations of CO2 at between 568 and 590 parts per million. While that’s higher than the current average level of 410 parts per million, it is in keeping with the rising trend which will arrive at 570 parts per million before the turn of the century.

Each variety of rice showed differing results, but on average the crops saw a loss of 10.3% protein, 8% iron and 5.1% zinc. Looking at the Chinese results in isolation, which also focused on vitamin levels, the rice declined in B1 by 17.1%, B2 by 16.6%, B5 by 12.7% and B9 by 30.3%. B6 remained unaffected and vitamin E showed a small rise, but on the whole the results were largely concerning.

Grave implications for Asian population

Rice is the main food source for over two billion people on the planet – which is almost a third of the entire population. Asia, in particular, could suffer adverse effects if the nutritional value of this important staple were to drop.

Nine of the 10 biggest consumers of rice are in Asia (along with Madagascar) and the authors of the study predict 600 million people could suffer from nutrient deficiencies as a result of these findings. B vitamins in particular play a vital role in motor-neuron and cognitive functions, from keeping the human brain in good working order to ensuring that the foetus develops into a baby as it should.

With another of the continent’s favourite foodstuff, seafood, under threat from water pollution, the future diet of Asian residents could require an overhaul if action is not taken to curb our harmful impact upon the environment.