A study published in the January edition of the journal Psychosomatic Medicine found a link between the consumption of fruits and vegetables and optimism.
According to the researchers from Brigham and Women's Hospital, Harvard University and the University of Wisconsin, people who eat three or more fruits and vegetables a day are more optimistic than those who consume two or fewer.
The study also found that the amount of carotenoids was up to 13% higher in the blood of more optimistic people than in that of less optimistic ones. Carotenoids, such as beta-carotene found in carrots, spinach and other vegetables, are a type of antioxidant. Antioxidants have been found to prevent production of free radicals in the body's molecules, thus promoting good health . The association between optimism and carotenoid concentration was explained in part by diet and smoking status.
In addition to carotenoids, the researchers also examined the levels of vitamin E in participants but found no significant association with optimism.
Participants in the study had their blood examined for concentrations of antioxidants and were asked about their degree of optimism only once. As a result, it is not clear whether a higher intake of fruits and vegetables and a higher concentration of antioxidants make people more optimistic or whether optimistic people consume more fruits and vegetables and adopt a healthier lifestyle, associated with higher antioxidant levels.
The study included 982 men and women aged between 25 and 74. It was based on previous research linking optimism with lower disease risk and biological dysfunction.