Instead of going out to lunch for that quarter-pounder bacon burger, why not just pick the salad bar? 

There have been several studies linking fruit and vegetable consumption with better mental health, and this week we add another published in Science Direct.

The study, punnily called “Lettuce be happy: A longitudinal UK study on the relationship between fruit and vegetable consumption and well-being” revealed these highlights:

  • Increased fruit & vegetable consumption can enhance mental well-being;
  • Increasing frequency and increasing quantity of consumption both matter;
  • The relationship is robust to different measures of well-being;
  • A hump-shaped relationship appeared between age and fruit and vegetable consumption.

Here is one of the more remarkable passages in the research paper:

Looking at our preferred fixed-effects specification, we find that increasing one’s consumption of fruit and vegetables by one portion (on a day where at least one portion is consumed) leads to a 0.133-unit increase in mental well-being (p < 0.01). The question remains: how large is this effect in practical terms? One way to gain an understanding of this issue is to compare the estimated change in mental well-being from increases in fruit and vegetable consumption to that of other commonly observed correlates with well-being. A five-portion increase in the number of fruits and vegetables consumed (on a day with positive consumption) would be associated with a 0.67-unit increase in mental well-being. From the coefficients in Table 1, we can see that this would be approximately equivalent in magnitude to the estimated well-being loss from widowhood (−0.68), and approximately one third of the estimated impact from unemployment, which is known to have one of the largest effects on subjective well-being. In terms of a factor that is more controllable at the individual level, our results show that increasing one’s daily consumption by one portion (on a day with positive consumption) provides the same estimated increase in mental well-being as 7.6 additional days of walking continuously for at least 10 min per 4 weeks.

The succinct conclusion of the paper, according to researchers:

"Our findings provide further evidence that persuading people to consume more fruits and vegetables may not only benefit their physical health in the long-run, but also their mental well-being in the short-run."

TK: This is incredible; as I read the research, an extra five portions of fresh produce compared with normal is as nearly positive for one’s mental outlook as becoming a widower is negative. I might crave that bacon double burger, but the true salve for the human condition seems to be found in the produce aisle.