Switching to veggies, fruit could help save groundwater in India

New Delhi, April 5

Modifying diets by a few grams like reducing consumption of poultry could significantly reduce groundwater use in India and help the country meet the challenge of feeding 1.64 billion people by 2050, a new study on Wednesday said.

The changes to diets include reducing the consumption of wheat and poultry, increasing the consumption of vegetables and legumes and switching to fruits like melon, oranges and papaya with lower water requirements in production, it said.

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Not only could these changes help reduce groundwater use, they could also cut greenhouse gases and have a positive effect on health, the new study published in the first issue of The Lancet Planetary Health said.

“Modifying diets by a few grams per day according to the composition of vegetables, fruit and meat could significantly reduce groundwater use in India, and help the country meet the challenge of feeding 1.64 billion people by 2050,” it said.

Observing that the availability of freshwater for irrigation in the Indian agricultural sector is expected to decline over the coming decades, it said that this might have implications for food production in India, with subsequent effects on diets and health.

Previous studies have looked at the impact of diets, especially red meat, on greenhouse gases.

However, this study published demonstrates how diets could be optimised to improve both human and environmental health, and play an important part in developing resilient food systems.

The study looked specifically at India, where around half of the usable water is currently required for irrigation.

The population of India is predicted to rise to 1.64 billion people by 2050 and in order to ensure enough freshwater is available, water use will need to be reduced by a third.

In this study, researchers looked at five typical dietary patterns in India and modelled how they could be optimised to reduce groundwater use, while meeting nutritional standards and maintaining overall energy intake.

They also modelled the effect of these changes to human health and greenhouse gas emissions.

Modifying the average diet to increase fruit consumption by 51.5 gm per day and vegetable consumption by 17.5 gm per day, along with a reduction in the consumption of poultry of 6.8 gm per day could lead to a 30 per cent reduction in freshwater use and a 13 per cent reduction in dietary greenhouse gas emissions, the study found.

“Food systems worldwide are likely to face increasing pressure as populations increase and water availability declines. In India, the proportion of freshwater available for agricultural production may already be unsustainably high and water availability per person is likely to decline significantly over the coming decades.

“Our study is the first to investigate the potential of changing diets as a solution to decreasing freshwater availability and finds modest dietary changes could help meet the challenge of developing a resilient food system in the country,” said James Milner, lead author from the London School of Hygiene and Tropical Medicine, UK.

In many parts of the world, freshwater sources are being depleted faster than they can be replenished and under climate change, rainfall is likely to become increasingly unpredictable.

As water availability declines and population increases, food systems around the world are put under significant pressure.

In the study, researchers optimised typical dietary patterns in an Indian population sample to meet projected decreases in the availability of water per person for irrigation (blue water footprint) due to population growth (to 2025 and 2050).

Resulting changes in life-years lost due to coronary heart disease, stroke, diabetes, and cancers were modelled using life tables, and changes in greenhouse gas emissions associated with the production of diets were estimated.

The primary outcomes of the model were changes in life-years per 1,00,000 total population over 40 years (to 2050).

“The optimised diets had up to 30 per cent lower blue water footprints and generally contained lower amounts of wheat, dairy, and poultry, and increased amounts of legumes.

“In the 2050 scenario, adoption of these diets would on average result in 6,800 life-years gained per 1,00,000 total population over 40 years.

“The dietary changes were accompanied by reductions in greenhouse gas emissions. The magnitude of the health and environmental effects varied between dietary patterns,” the study said. — PTI