Abstract
Background: The association between a plant-based diet (vegetarianism) and extended life span is increasingly criticised since it may be based on the lack of representative data and insufficient removal of confounders such as lifestyles.
Aim: We examined the association between meat intake and life expectancy at a population level based on ecological data published by the United Nations agencies.
Methods: Population-specific data were obtained from 175 countries/territories. Scatter plots, bivariate, partial correlation and linear regression models were used with SPSS 25 to explore and compare the correlations between newborn life expectancy (e(0)), life expectancy at 5 years of life (e(5)) and intakes of meat, and carbohydrate crops, respectively. The established risk factors to life expectancy - caloric intake, urbanization, obesity and education levels - were included as the potential confounders.
Results: Worldwide, bivariate correlation analyses revealed that meat intake is positively correlated with life expectancies. This relationship remained significant when influences of caloric intake, urbanization, obesity, education and carbohydrate crops were statistically controlled. Stepwise linear regression selected meat intake, not carbohydrate crops, as one of the significant predictors of life expectancy. In contrast, carbohydrate crops showed weak and negative correlation with life expectancy.
Conclusion: If meat intake is not incorporated into nutrition science for predicting human life expectancy, results could prove inaccurate.
Keywords: agriculture; ecological study; evolution; life expectancy; meat intake; vegetarian
You, Wenpeng