No, it’s not surprising, but it’s important: people who eat better food– more whole grains, vegetables, fruits, nuts, and fish and less red and processed meats and sugary beverages–live longer than people who don’t. We know that because, well it makes sense, but also because researchers at Harvard’s T. H. Chan School of Public Health have analyzed the association between changes in diet quality among nearly 74,000 adults over a 12-year period (1986-1998) and their risk of dying over the subsequent 12 years (1998-2010). A Chan School news release reports that the researchers assessed diet quality by using three different scoring methods: the 2010 Alternate Healthy Eating Index, the Alternate Mediterranean Diet score, and the Dietary Approaches to Stop Hypertension (DASH) diet score, with each method assigning scores to various types of food or nutrients; less healthy foods or nutrients have lower scores and healthier foods or nutrients have higher ones. What did they find? That improved diet quality over a 12-year period was associated with reduced risk of death in the subsequent 12 years, no matter which score was used. Food groups that contributed most to an improvement in diet quality were whole grains, fruits, vegetables, and fish or n-3 fatty acids. And now the numbers: a 20-percentile increase in diet-quality scores—the kind of increase that can be achieved by swapping out just one serving of red or processed meat for one daily serving of nuts or legumes—was linked with an 8 percent to 17 percent reduction in the risk of death, depending on the diet score. In contrast, worsening diet quality was associated with a 6 percent to 12 percent increase in the risk. People who maintained higher rather than lower scores according to any of the three healthy diet patterns for 12 years, had a 9 percent to 14 percent reduction in mortality from any cause. Among those who had relatively unhealthy diets at the beginning of the study but whose diet scores improved the most, the risk of death in subsequent years was also significantly reduced.