Happiness benefits were detected for each extra daily portion of fruit and vegetables up to 8 portions per day.
The researchers concluded that people who changed from almost no fruit and veg to eight portions of fruit and veg a day would experience an increase in life satisfaction equivalent to moving from unemployment to employment. The well-being improvements occurred within 24 months.
The study followed more than 12,000 randomly selected people. These subjects kept food diaries and had their psychological well-being measured. The authors found large positive psychological benefits within two years of an improved diet.
Professor Andrew Oswald said: "Eating fruit and vegetables apparently boosts our happiness far more quickly than it improves human health. People's motivation to eat healthy food is weakened by the fact that physical-health benefits, such as protecting against cancer, accrue decades later. However, well-being improvements from increased consumption of fruit and vegetables are closer to immediate."
The work is a collaboration between the University of Warwick, England and the University of Queensland, Australia.
The study has policy implications, particularly in the developed world where the typical citizen eats an unhealthy diet. The findings could be used by health professionals to persuade people to consume more fruits and vegetables.
