Food choices influence the planet

Climate change is rightly occupying a lot of the debate about our planet’s future and the need to be mindful stewards of the environment in which we live. The environment is, however, a complex organism and we need to keep many balls in the air if we are to support it. Climate change is one of those balls and new study has highlighted another one of those balls: phosphorous levels.

Phosphorous is essential for all living things and therefore is intimately involved in food production. The conventional farming industry needs phosphorous to produce fertilisers that support crop production. Mined phosphate from rock, however, is a non-renewable resource. While phosphorous is essential to life, the problem lies in the loss of phosphorous into waterways as run-off from farm fields or urban sewage through human excrement. In the waterways, phosphorous in excess severely degrades water quality and leads to eutrophication (excessive nutrient presence leading to plant overgrowth such as harmful algal blooms) and impairment of drinking water and fisheries.

This means that an increased demand for fertilisers in food production actually threatens our water security. It is yet another argument in favour of biodynamic farming practices but it also poses the question of what we should be eating if we want to reduce levels of phosphorous in our farming.

Researchers wanted to see how it would play out in terms of phosphorous if residents of Australian cities switched their diet from meat- to plant-based foods.

A lot has been said and written about the benefits of a plant-based diet both for the individual and the planet but these researchers wanted to see how it would play out in terms of phosphorous if residents of Australian cities switched their diet from meat- to plant-based foods. To do this, they generated modelling that calculated the phosphorous footprint (the amount of phosphorous mined to support your diet) if you changed your consumption of meat, dairy, eggs and seafood to pulses (beans and legumes).

We know, for instance, that 1kg of phosphorous will produce either 3333kg of potatoes or 16kg of beef. According to this analysis, shifting towards plant-based foods would result in an 8 per cent increase in phosphorous excreted by humans but overall there would be 72 per cent reduction in phosphorous footprint.

The researchers concluded that shifting towards a plant-based diet would reduce mined phosphorous and therefore reduce the negative impact of humans on the environment.

Source: Frontiers in Nutrition