As we consider the dramatic increase of depression in modern society, it is increasingly becoming evident that our diets are a significant cause for this mental health crisis. This is after multiple studies are confirming that eating more fruits and vegetables increase positive moods and reduce the incidence and symptoms of depression.
Studies have shown that most people consume pitifully small amounts of fruits and vegetables daily. In one large study from Australia for example,4 researchers found that nearly 30 percent of people only consume fruit between one and three times a week, and about 20 percent only consume vegetables one to three times a week. Furthermore, less than half of the population will consume fruit or vegetables daily.
As we’ll discuss in this article, there are multiple large population studies that are showing that fruits and vegetables significantly decrease the incidence of depression symptoms and negative moods. Let’s discuss some of the larger studies, along with the supporting evidence.
Large study connects depression to diet
Researchers from the University of Leeds in the U.K. and the U.K.’s University of York1 analyzed and followed about 50,000 people in the United Kingdom over a period of 8 years (from 2009 to 2017).
The researchers questioned each person about the amount of fruits and vegetables they ate a day. They also conducted annual visits along with either a survey or home interview to determine the mental well-being and extent of any psychiatric disorders among the volunteers.
The researchers amassed weekly vegetable and fruit consumption reporting and compared this with moods and psychiatric profiles of the subjects. They scaled a mental well-being rating for each along with a life satisfaction rating for each subject.
The data concluded that well-being and life satisfaction levels were dramatically higher among those who ate more fruits and vegetables. Those who ate fruits every day had more than three times the life satisfaction levels than those who ate fruits from one to three days each week. Those who ate vegetables every day had over 70 percent higher levels of life satisfaction compared to those who ate veggies one to three days a week.
As for mental well-being, those who ate fruit every day had over double the levels of mental well-being scores compared to eating fruits for between one and three days. And eating vegetables daily resulted in about triple the scores of mental well-being compared to those who ate vegetables for between one and three days.
The researchers also found that increasing fruit and vegetable consumption significantly boosted moods and life satisfaction levels among those studied. For example, increasing vegetable consumption from never to four to six times a week boosted moods and life satisfaction to levels seen in getting married.
They also found that increasing the frequency of fruit and vegetable consumption significantly had a life satisfaction equivalent of an unemployed person finding a job.
Mental well-being connected to diet nutrients
In a 2019 study from the University of Manchester,2 led by Dr. Joseph Firth, led a study that analyzed 16 studies that totaled 45,826 volunteers. The researchers found that improving one’s diet and the nutritional quality of the diet with respect to more fruits and vegetables significantly decreased symptoms of depression. Diets with more nutrition also boosted mental well-being – established also in the University of Leeds study above.
The research also established that a general boost in dietary quality – rather than special diets – can benefit the person in terms of moods and depression, according to Dr. Firth:
“The similar effects from any type of dietary improvement suggests that highly-specific or specialized diets are unnecessary for the average individual.”
Study co-author Dr Brendon Stubbs, who also teaches at the King’s College London, concluded the results by stating:
“Our data add to the growing evidence to support lifestyle interventions as an important approach to tackle low mood and depression.”
The study also found that benefits of diet improvement affected women in a more broad way compared to men. This is consistent with other research finding that a woman’s body tends to be more sensitive to nutrients and supplements, and drug side-effects are often greater in women.
This is supported by other research
We have reported on previous research that came with similar conclusions.
For example, a 2018 study from New Zealand’s University of Otago found that eating raw fruits and vegetables significantly improved mental health and decreased symptoms of anxiety and depression.
In a study from the Physicians Committee for Responsible Medicine, researchers found that eating a plant-based diet decreased symptoms of depression, anxiety and fatigue, while boosting well-being, general health, daily functioning, and impairment.
Other studies have found similar evidence. Another 2019 paper from Australian researchers3 has found that eating more fruits and vegetables also impacts clinical symptoms and diagnosis of depression and anxiety. The researchers stated:
“We show, in Australian data, that an equivalent result may be true for actual clinical diagnosis of depression and anxiety. We conclude that there appears to be accumulating evidence for the psychological power of fruit and vegetables.”
1. Ocean N, Howley P, Ensor J. Lettuce be happy: A longitudinal UK study on the relationship between fruit and vegetable consumption and well-being. Soc Sci Med. 2018 Dec 31. pii: S0277-9536(18)30690-7. doi: 10.1016/j.socscimed.2018.12.017.