“For citrus consumption, participants were prompted regarding their frequency (ranging from never to six or more servings daily) of consuming grapefruit, oranges, grapefruit juice, and orange juice during the past year,” the study explains. “Total citrus intake was assessed by aggregating the consumption of each individual item.”
I trust you enjoy citrus fruits (Getty Stock Images)
In addition to considering other dietary components, the study also inquired every two years if participants had ever been diagnosed with depression and their use of antidepressants.
The study evaluated the effects of increased citrus intake on the gut microbiome – specifically identifying which microbial species were more prevalent – and subsequently examined how certain microbial species were linked to depression.
The study concludes: “From 2003 through 2017, we identified 2,173 cases of depression among 32,427 women who reported no self-reported physician/clinician-diagnosed depression and regular antidepressant use at baseline.”
“Over 222,923 person-years of follow-up, compared with participants in the lowest quintile of citrus intake, those in the highest quintile exhibited a 22 percent reduced risk of depression.”
The study then investigated whether the risk of depression was diminished by ‘total fruit’ and ‘total vegetable’ intake rather than exclusively citrus fruit.
However, Harvard Medical School instructor and Massachusetts General Hospital physician Raaj Mehta – the study’s leader – conveyed to The Harvard Gazette: “The effect appears to be particular to citrus. When we evaluate total fruit or vegetable consumption, or other individual fruits like apples or bananas, we do not observe any connection between intake and depression risk.”
Moreover, the effect can occur from simply ‘consuming one medium orange daily.’
Across two cohorts of data overall, the study indicates that ‘citrus intake is prospectively associated with a higher abundance of F. prausnitzii, which is linked with a reduced risk of depression.’
While Mehta acknowledges that ‘further research is necessary’ to compare citrus with traditional antidepressants, the study concludes: “This finding reinforces the idea that dietary changes can alleviate or prevent depression symptoms and, importantly, presents new opportunities for therapeutic and/or biomarker development.”
Featured Image Credit: Getty Stock Images