Newswise, July 29, 2016-- University of Warwick research
indicates that eating more fruit and vegetables can substantially increase
people’s later happiness levels.
Published in the prestigious American Journal of
Public Health, the study is one of the first major scientific attempts to
explore psychological well-being beyond the traditional finding that fruit and
vegetables can reduce risk of cancer and heart attacks.
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.
Cancer
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 researchers found that
happiness increased incrementally for each extra daily portion of fruit and
vegetables up to eight portions per day.
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.
Western diet
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.
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.”
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.
The campaign was run in some Australian states which have
promoted the consumption of two portions of fruit and five portions of
vegetables each day.
Antioxidants
The academics think it may be possible eventually to 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.