Published in the American Journal of Public Health, the study is one of the first major scientific attempts to explore psychological wellbeing beyond the traditional finding that fruit and vegetables can benefit our physical health.
The research, collaboration between the University of Queensland, Australia and the University of Warwick in England, suggests that people who went from almost no fruit and veg to eight portions a day would experience an increase in life satisfaction equivalent to moving from unemployment to employment.
The study followed more than 12,000 randomly selected people who kept food diaries and had their psychological wellbeing measured. The authors found large positive psychological benefits within two years of an improved diet.
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"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, […], accrue decades later. However, wellbeing improvements from increased consumption of fruit and vegetables are closer to immediate," they noted.
The study involved an examination of longitudinal food diaries of 12,385 randomly sampled Australian adults over 2007, 2009, and 2013 in the Household, Income, and Labour Dynamics in Australia Survey. The authors adjusted the effects on incident changes in happiness and life satisfaction for people's changing incomes and personal circumstances.
Dr Redzo Mujcic, research fellow at the University of Queensland, said: "Perhaps our results will be more effective than traditional messages in convincing people to have a healthy diet. There is a psychological payoff now from fruit and vegetables - not just a lower health risk decades later."
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The authors found that alterations in fruit and vegetable intake were predictive of later alterations in happiness and satisfaction with life. They took into account many other influences, including changes in people's incomes and life circumstances. One part of the study examined information from the Australian 'Go for 2&5' campaign, run in some Australian states, and promoted the consumption of two portions of fruit and five portions of vegetables each day.
The researchers also think it may be possible to eventually link this study to current research into antioxidants which suggests a connection between optimism and carotenoid in the blood. However they argue that further research is needed in this area.
Source: American Journal of Public Health, August 2016, Vol. 106, No. 8, pp. 1504-1510. doi: 10.2105/AJPH.2016.303260
This article originally appeared on the Blackmores Institute