The research, recently published in the International Journal of General Medicine, has examined the effects on health in more than 170 countries, and in its conclusions, it states: "this study has shown that meat consumption is positively associated with life expectancy at the national level. The underlying reasons may be that meat provides not only energy but also complete nutrients for the human body. From an evolutionary standpoint, meat has arguably been an indispensable component of the human diet for millions of years, evidenced, genetically, by the digestive enzymes in meat and the anatomy of the digestive tract. The complete nutritional profile of meat and the human adaptation to meat consumption have allowed humans to obtain many physical benefits, including a longer life expectancy. Meat consumption, or its appropriate replacement, should be incorporated into nutritional science."
Study author, biomedical researcher Dr. Wenpeng You, says humans have evolved and thrived for millions of years because of their significant meat consumption. "We wanted to take a closer look at research that has shed a negative light on meat consumption in the human diet," says Dr. You. "Looking only at correlations of meat consumption with the health or life expectancy of people within a particular group and/or a particular region or country can lead to complex and misleading conclusions. Our team extensively analyzed the correlations between meat consumption and life expectancy, and infant mortality, globally and regionally, minimizing the bias of the study and making our conclusion more representative of the overall effects of meat consumption on health."
The researchers found that energy intake from carbohydrate crops (cereals and tubers) does not lead to longer life expectancy, and that total meat consumption correlates with longer life expectancy, independent of the competing effects of total calorie intake, economic wealth, urban advantage, and obesity.
"While detrimental effects of meat consumption on human health have been found in some previous studies, the methods and findings of these studies are controversial and circumstantial," says Dr. You. In turn, another of the study's authors, University of Adelaide emeritus professor Maciej Henneberg, says that humans have adapted to eating meat from their evolutionary perspective of more than two million years.
"Meat from small and large animals provided optimal nutrition for our ancestors who developed genetic, physiological and morphological adaptations to eat meat products, and we have inherited those adaptations," says Professor Henneberg.
But with the strong development of nutrition science and economic affluence, studies in some populations in developed countries have associated meat-free (vegetarian and vegan) diets with better health. "I think we need to understand that this may not contradict the beneficial effect of meat consumption," says the study's nutritionist, Yanfei Ge.
"Studies looking at the diets of wealthy, highly educated communities are looking at people who have the purchasing power and knowledge to select plant-based diets that access all the nutrients normally contained in meat. Essentially, they have replaced meat with the same nutrition that meat provides."
Co-author and University of Adelaide biologist Dr. Renata Henneberg says that today meat remains an important food component in the diets of many people around the world. "Before agriculture was introduced 10,000 years ago, meat was a staple in the human diet," she says.
"Depending on the smaller groups of people you study and the types of meat you choose to consider, the extent of meat's role in managing human health may vary. However, when all types of meat are considered for all populations, as they are in this study, the positive correlation between meat consumption and overall health at the population level is not sporadic."
University of Adelaide anthropologist and Polish Academy of Sciences biologist Dr. Arthur Saniotis says the findings are in line with other studies showing that cereal-based foods have lower nutritional value than meat.
"While this is not a surprise to many of us, it still needs to be pointed out," says Dr. Saniotis. He stresses that meat has its own components that contribute to our overall health beyond the amount of calories consumed, and that without meat in our diet, we may not thrive.
"Our final message of the paper is that meat consumption is beneficial to human health as long as it is consumed in moderation and the meat industry is conducted in an ethical manner."