Plant-based diet best for planet and people
As cities grow and incomes rise around the world, more and more
people are leaving gardens and traditional diets behind and eating
refined sugars, refined fats, oils and resource- and land-intense
agricultural products like beef. This global dietary transition is
harming the health of both people and the planet, says new research.
But the study also shows that shifting away from this trajectory and
choosing healthier traditional Mediterranean, pescatarian or vegetarian
diets could not only boost human lifespans and quality of life, but also
slash emissions and save habitat for endangered species.
And we better hurry; the scientists project that if the trend
continues, the situation will be worse yet with greenhouse gas emissions
up by 80 percent by 2050.
Examining almost 50 years' worth of data from the world's 100 most
populous countries, University of Minnesota Professor of Ecology G.
David Tilman and graduate student Michael Clark illustrate how current
diet trends are contributing to ever-rising agricultural greenhouse gas
emissions and habitat degradation.
On top of that, they write: "These dietary shifts are greatly
increasing the incidence of Type 2 diabetes, coronary heart disease and
other chronic non-communicable diseases that lower global life
expectancies."
In the study, published in the November 12 online edition of
*Nature*, the researchers found that as incomes increased between 1961
and 2009 people began consuming more meat protein, "empty calories" and
total calories per person. ("Empty calories" - sugar, fat, oils and
alcohol - now account for almost 40 percent of food purchased in the
world's 15 wealthiest countries, according to the research.) When the
researchers combined the trends with forecasts of population growth and
income growth for the coming decades, they were able to project that
diets in 2050 will contain fewer servings of fruits and vegetables,
about 60 percent more empty calories and 25 to 50 percent more pork,
poultry, beef, dairy and eggs.
These are changes that are known to increase the prevalence 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 percent increase in global greenhouse gas
emissions from food production as well as habitat destruction due to
land clearing for agriculture around the world.
"We showed that the same dietary changes that can add about a decade
to our lives can also prevent massive environmental damage," said Tilman,
a professor in UM's College of Biological Sciences and resident fellow
at the Institute on the Environment.
"In particular, if the world were to adopt variations on three common
diets, health would be greatly increased at the same time global
greenhouse gas emissions were reduced by an amount equal to the current
greenhouse gas emissions of all cars, trucks, plans trains and ships. In
addition, this dietary shift would prevent the destruction of an area of
tropical forests and savannahs as large as half of the United States."
The study compared health impacts of the global omnivorous diet with
those reported for traditional Mediterranean, pescatarian and vegetarian
diets.
Adopting these alternative diets could reduce incidence of type II
diabetes by about 25 percent, cancer by about 10 percent and death from
heart disease by about 20 percent relative to the omnivore diet.
Adopting these or similar alternative diets would also prevent most
or all of the increased greenhouse gas emissions and habitat destruction
that would otherwise be caused by both dietary changes and increased
global population.
The authors acknowledged that numerous factors go into diet choice -
but also pointed out that the alternative diets already are part of the
lives of countless people around the world.
"This is the first time this data has been put together to show these
links are real and strong and not just the mutterings of food lovers and
environmental advocates," Tilman said.
- OurWorld |