Effect of 4 weeks daily wild blueberry supplementation on symptoms of depression in adolescents

Abstract

Adolescence is an important period for cognitive maturation and emotional regulation, and this age group is particularly vulnerable to developing depression. Diets rich in fruits and vegetables have been associated with decreased risk of developing depressive disorders across the lifespan, maybe due to the high flavonoid content of these foods. Previously, we have shown increases in transient positive affect (PA) in both children and young adults 2 h after administration of a wild blueberry (WBB) intervention. Here, using a randomised double-blind, placebo-controlled trial, we investigated the effects of 4 weeks, daily WBB supplementation (containing about 253 mg anthocyanins) on transient and chronic mood in adolescents. Healthy 12–17-year old (n 64, thirty-five females) participants were randomly assigned to receive either a WBB or matched placebo supplementation. Depression and anxiety symptoms were assessed before and after the intervention period using the Mood and Feeling Questionnaire and Revised Child Anxiety and Depression Scale. Transient affect was assessed before, 2 weeks and at 4 weeks using PA and negative affect. Following the intervention period, there were significantly fewer self-reported depression symptoms in participants who were supplemented with WBB compared with placebo (P = 0·02, 95 % CI –6·71, –5·35). There was no between-group effect on anxiety symptoms or on transient affect. Further investigation is required to identify specific mechanisms that link flavonoids consumption and mood. If replicated, the observed effects of WBB supplementation may be a potential prevention strategy for adolescent depression and may have benefits for public mental health.

Effects of daily consumption of wild blueberry on cognition and urinary metabolites in school-aged children: a pilot study

“…Specifically, research into polyphenol-rich blueberries has revealed cognitive benefits in healthy adults [6][7][8][9][10] and children [11][12][13][14][15]. Positive effects on mood have also been observed across healthy adult [16], child [17] and adolescent [18] cohorts. Collectively, polyphenols have important implications for maintaining cognitive function and mental health across the lifespan.…”

Mental Health in New Mothers: A Randomised Controlled Study into the Effects of Dietary Flavonoids on Mood and Perceived Quality of Life

“…An a-priori power calculation using GPower 3.1 [ 39 ] revealed that 44 participants were required to achieve a power of 0.8 using an effect size (Cohen’s d ) of 0.22 (F(1,42) = 4.07). This effect size was used based on prior research that has shown significant flavonoid-related mood effects [ 9 , 10 ]. A post-hoc power analysis confirmed that a sufficient power of 0.78 was achieved with the current sample size of 41 (F(1,39) = 4.09).…”

“…The beneficial effects of polyphenols on health ([ 1 , 2 , 3 ] for reviews) and cognition ([ 4 , 5 , 6 , 7 , 8 ] for reviews) have been well reported within the literature. Recent investigations have focused on the impact of polyphenols on mood and have discovered advantageous effects in healthy child [ 9 ], adolescent [ 10 ] and adult [ 9 , 11 ] populations after polyphenol-rich food interventions. Such findings suggest that consuming foods high in flavonoids may improve or maintain positive mood in healthy populations.…”

“…A recent review [ 26 ] identified 29 studies where symptoms of depression in young adult populations were alleviated following polyphenol intervention, indicating a clear link between high consumption levels and improved mood outcomes. It is interesting to note that there are a number of studies showing that dietary sources of anthocyanins or flavanones have beneficial effects on chronic mood [ 10 , 11 ]. For example, Pase et al [ 11 ] reported significantly enhanced feelings of calmness and contentedness in middle-aged adults (40–65 years) following a 30-day daily cocoa intervention.…”

“…For example, Pase et al [ 11 ] reported significantly enhanced feelings of calmness and contentedness in middle-aged adults (40–65 years) following a 30-day daily cocoa intervention. Across a similar timeframe, positive mood effects were also observed in an adolescent population (12–17 years), with participants reporting significantly lower depressive symptoms at the end of a 4-week daily wild blueberry intervention [ 10 ]. Improvements in quality of life have also been observed in a depressed sample (50–55 years) following a 12-week daily soy and resveratrol intervention [ 27 ].…”