A new study shows that healthier food choices could dramatically lower greenhouse gas emissions and also protect endangered species – all while boosting our lifespans and quality of life.
As cities grow and incomes rise around the world, people tend to consume more refined sugars, refined fats and oils, as well agricultural products that require a higher number of resources and land such as beef.
A study led by University of Minnesota ecologist David Tilman and graduate student Michael Clark found that a shift away from this trajectory and toward healthier traditional Mediterranean, pescatarian (which allows fish but not other animals) or vegetarian diets could not reduce the incidence of type II diabetes, coronary heart disease and other chronic diseases, but also slash greenhouse gas emissions and protect against habitat degradation.
“We showed that the same dietary changes that can add about a decade to our lives can also prevent massive environmental damage,” said Tilman. In particular, global greenhouse gas emissions could be reduced by an amount equal to the current emissions of all cars, trucks, planes, trees and forests. It would also prevent the destruction of an area of tropical forests and savannahs as large as half of the United States.
The researchers found that, as incomes increased between 1961 and 2009, people consumed more meat protein, empty calories and total calories per person. When these trends were combined with forecasts of population growth and income growth for the coming decades, the study predicted that diets in 2050 would contain fewer servings of fruits and vegetables, but about 60 per cent more empty calories and 25 to 50 per cent more pork, poultry, beef, dairy and eggs — a suite of changes that would increase incidence of type II diabetes, coronary heart disease and some cancers.
Using life-cycle analyses of various food production systems, the study also calculated that, if current trends prevail, these 2050 diets would also lead to an 80 per cent increase in global greenhouse gas emissions from food production as well as habitat destruction due to land clearing for agriculture around the world.
The study then compared health impacts of the global omnivorous diet with those reported for traditional Mediterranean, pescatarian and vegetarian diets. Adopting these alternative diets could not only reduce the incidence of type II diabetes, cancer or death from heart disease, but they would also prevent most or all of the increased greenhouse gas emissions and habitat destruction that would otherwise be caused by both current diet trends and increased global population.