A team of scientists from Australia, Italy, Poland and Switzerland has examined the association between meat intake and life expectancy at a population level based on ecological data published by the United Nations agencies.
“Life expectancy at birth is the measure synthetically describing mortality in a population,” said lead author Dr. Wenpeng You, a researcher at the University of Adelaide and FAPAB Research Center, and colleagues.
“It is estimated that 20-30% of human life expectancy is determined by genetic factors, and 70-80% is determined by environmental factors.”
“Life expectancy at 5 years of age is similarly influenced by genetic factors, while it excludes neonatal, infant and early childhood mortality that depends heavily on environmental factors, especially hygiene and infection controls.”
“The effects of meat eating on human health have been debated in nutrition and diet research for a long time,” they added.
“Over the last 50 years, although the associations between meat eating and illness are circumstantial and controversial to some extent, they have prompted the spread of vegetarianism and veganism, based on the assumption that non-meat diets provide more health benefits than diets that include meat.”
“Moreover, it has been argued that vegetarianism and veganism form a part of ‘trendy’ Western consumerist lifestyles — only accessible to privileged ‘white’ people.”
“Vegetarianism that has been prevalent in Western countries has been subject to prejudice, low self-esteem, and low psychological adjustment.”
“To date, there has been prevailing research stating that vegetarians tend to have greater life expectancy compared with non-vegetarians in some populations. However, lack of population representativeness and failure to remove the influence of lifestyle in these studies have been heavily criticized.”
“Our population-based study, using data collected by the United Nations and its agencies, tests the hypothesis that, worldwide, populations with more meat consumption have greater life expectancies.”
In the study, Dr. You and co-authors examined the overall health effects of total meat consumption in 175 countries around the world.
The researchers found that the consumption of energy from carbohydrate crops (grains and tubers) does not lead to greater life expectancy, and that total meat consumption correlates to greater life expectancy, independent of the competing effects of total calories intake, economic affluence, urban advantages, and obesity.
“Humans have adapted to meat-eating from the perspective of their more than two million years evolution,” said Professor Maciej Henneberg, a researcher at the University of Adelaide and the University of Zürich.
“Meat of small and large animals provided optimal nutrition to our ancestors who developed genetic, physiological, and morphological adaptations to eating meat products and we have inherited those adaptations.”
“The findings are in line with other studies that show cereal-based foods have lower nutritional value than meat,” said Dr. Arthur Saniotis, a researcher at the University of Adelaide and the Ludwik Hirszfeld Institute of Immunology and Experimental Therapy.
“While this is no surprise to many of us, it still needs to be pointed out.”
“It highlights that meat has its own components contributing to our overall health beyond just the number of calories consumed, and that without meat in our diet, we may not thrive.”
“Our take home message from the paper is that meat-eating is beneficial to human health provided that it is consumed in moderation and that the meat industry is conducted in an ethical way.”
The team’s results are published in the International Journal of General Medicine.