The study assessed the blood concentrations of nine antioxidants - including carotenoids, which are a class of antioxidants mostly found in orange-colored produce - in 1,000 male and female participants between the ages of 25 and 74. During the assessment, the participants completed a questionnaire about their attitudes on life.
The scientists found that the most optimistic participants each had up to a 13 percent increase in blood concentrations of carotenoids compared to those who were less optimistic. Moreover, the scientists also found that the participants who consumed fewer than three servings of fruits and vegetables per day were considerably less optimistic than those who consumed more than three servings per day.
"Individuals with greater optimism tended to have greater levels of carotenoids such as beta-carotene," said the study's lead investigator, Julia Boehm. "This is the first study of its kind to report a relationship between optimism and healthier levels of carotenoid concentrations."
Other studies have linked antioxidant-rich foods to mental wellness
While Boehm's study for the Harvard School of Public Health might be the first to directly address the connection between antioxidant-rich foods and optimism, it is only one of many to address the overall psychological benefits of consuming natural produce.
A series of studies co-authored by professor Sarah Stewart-Brown at the University of Warwick, for instance, showed that individuals who consumed the most fruits and vegetables were least likely to suffer from depression, anxiety, and other mental issues. They also tended to be more satisfied with their lives.
"In every study we looked at, there was a correlation in fruit and vegetable consumption and mental health," said Stewart-Brown. "What's more, every additional portion increased the level of well-being." The happiest people in the studies, she added, were those that consumed eight servings of fruits and vegetables per day.
