Updated: Apr 16, 2019
‘1 in 6 people aged 16+ had experienced symptoms of a common mental health problem, such as depression or anxiety, in the past week’ (1). Additionally, there were nearly 6,000 deaths due to suicide in the UK in 2017 (2), considering this, there has never been a more vital time to find out if specific foods can impact mental wellbeing. A study published very recently is building on a growing body of evidence looking into fruit and vegetable consumption and mental wellbeing.
The recent research:
Ocean, N., Howley, P. and Ensor, J., 2019. Lettuce be happy: A longitudinal UK study on the relationship between fruit and vegetable consumption and well-being. Social Science & Medicine.
This provides a useful addition to current research base showing an association with increased fruit and veg munching with better mental wellbeing scores, but it is not strong enough to prove whether or not fruit and vegetables definitely causes increased mental wellbeing. However, as we know, increasing fruit and veg consumption is generally beneficial (3) so if there is also a potential upside for mental wellbeing then that’d be the cherry on the cake. So either way, munch more fruits and veggies and hopefully a randomised control trial will be completed soon to confirm these initial findings.
Strengths of the study
Large sample of data analysed
Tracked people over time rather than taking a snapshot
Confirmed findings from other UK studies as well as Australian research
Backed up by mechanistic evidence
Surveys were used in the study which can lead to bias (social desirability bias + recall bias)
As this was not a controlled trial you cannot draw out cause and effect
Reverse causality may be at play, instead of fruits and veggies leading to increased mental wellbeing, improved mental wellbeing may lead people to consume with higher amounts of fruits and vegetable.
50,000 surveys were analysed
78% of individuals did not eat 5 pieces of fruit and veg a day
Participants range from aged 15 to 104
Fruit and veg consumption increases until age 64 where is declines
Females eat more fruit and veg, more often
The researchers found the more fruit and veg consumed, the higher the mental wellbeing score, with no plateau for higher scores meaning it is a dose-dependent relationship.
1 Stansfield, S., Clark, C., Bebbington, P., King, M., Jenkins, R. & Hinchliffe, S. (2018) Common mental disorders. Retrieved from the UK Parliament Website: https://researchbriefings.parliament.uk/ResearchBriefing/Summary/SN06988
2 Office for National Statistics (2017). Suicides in the UK. Available at: https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarri... [Accessed on 21/08/18].
3. Slavin, J.L. and Lloyd, B., 2012. Health benefits of fruits and vegetables. Advances in nutrition, 3(4), pp.506-516.