7-a-day contributes to good mental health
Eating seven portions of fruit and vegetables each day may be the optimum for keeping us cheerful, experts suggest
11th October 2012 - Official advice is that we should be eating five portions of fruit and vegetables each day to help protect against heart disease and cancer. However, a new study says that extending this to seven a day could help ensure good mental health too.
The study, which is due to be published in the journal Social Indicators Research is based on the eating habits of thousands of Britons.
According to the British Dietetic Association people in the UK are still, on average, eating less than three portions of fruit and vegetables a day, with only 15% of adults meeting the target of 5-a-day.
Researchers from the University of Warwick and Dartmouth College in the US say the link between diet and physical health has been the subject of much research. However, there have been few investigations into how diet can affect our psychological wellbeing.
British health surveys
To help address this deficit, they obtained data about eating habits of around 80,000 randomly selected individuals from three separate surveys in England, Scotland and Wales.
They found that in all three studies there was evidence that increased consumption of fruit and vegetables improved mental wellbeing. They also discovered that this holds true once several other factors that might influence mental health have been screened out.
Furthermore, this effect of fruit and vegetable eating increases with each 80g portion, reaching an optimum level at seven portions each day. Co-author Professor Sarah Stewart-Brown from Warwick Medical School, Coventry tells BootsWebMD: "The health effects seemed to go on beyond five, so you could still see an additional health effect from eating six or an additional health effect from eating seven or eating eight."
The researchers argue that longer running, randomised controlled studies would be needed to further test their findings and that health professionals and other researchers should be made aware of the latest evidence, while being cautioned that there is a lack of clinching proof behind the 7-a-day findings.
Professor Stewart-Brown says: "This paper suggests that fruit and vegetables probably have an impact on your mental health as well as your physical health, and secondly that 5-a-day may not be the optimum.
"It may be important to eat more than that, but we still don't really know for absolute certain. So, it's like a lot of research - there are questions it raises as well as answers it gives."