Diet diversity lengthens life expectancy
A greater diversity of diet appears to lead to a longer life expectancy, a recent study has shown.
Drawing from the Global burden of Disease 2015 database, researchers assessed healthy life expectancy (HALE) data of 195 countries and territories. Dietary diversity across 12 different food groups was assessed using the Quantitative Index for Dietary Diversity (QUANTIDD).
Japan demonstrated the highest HALE value and the second-highest QUANTIDD score. New Zealand topped the QUANTIDD ranking, while Spain ranked second for HALE. The lowest HALE belonged to Haiti, while the lowest QUANTIDD was from Lesotho. In general, developed countries had higher HALE and QUANTIDD.
Multiple regression models controlled for gross domestic product (GDP) showed a significant cross-sectional relationship between QUANTIDD and HALE (β, 73.2±11.0; p<0.001) and life expectancy (LE; β, 81.1±12.3; p<0.001). In contrast, QUANTIDD negatively correlated with percentage difference between LE and HALE (β, –3.7±1.5; p=0.016).
These relationships mostly remained significant even after additional adjustments for ageing rate, health expenditure, energy supply and education years (HALE: β, 36.4±11.3; p=0.002; LE: β, 41.9±12.8; p=0.001).
Researchers also performed a longitudinal analysis spanning 15 years and including 137 countries. In the GDP-adjusted models, QUANTIDD remained significantly correlated with HALE (β, 49.6±5.0; p<0.001), LE (β, 56.2±5.7; p<0.001) and the percentage difference between the two (β, –1.9±0.5; p<0.001).
The same was true even after further controlling for socioeconomic factors of the country (HALE: β, 39.7±5.1; p<0.001; LE: β, 44.6±5.8; p<0.001; their percentage difference: β, –1.3±0.5; p=0.01).