Research

Effects of acute blueberry flavonoids on mood in children and young adults

The consumption of flavonoid-rich food is associated with decreased risk of developing depression. The possible explanation for this association is the beneficial effect of flavonoids on executive function (EF). EF describes cognitive processes, such as working memory, planning, problem-solving, cognitive flexibility, directing attention, thoughts and, therefore, behavior.   

EF is connected with the development of the frontal area of the brain, which continues to mature     throughout adolescence and into early adulthood. Therefore any disturbance to the frontal area during this period, such as an episode of depression, may lead to the long-lasting impairments into adult life. Impaired ES may maintain depressive symptoms, such as negative self-perception and low mood.    

This study investigated the acute effects of flavonoid-rich blueberry (WBB) on mood state. The study was conducted with two age-groups:

1) Young adults, age 18 – 21 (21 participants, of which 19 females and two males). The flavonoid-rich wild blueberry (WBB) drinks used in the study were:

  • 30 g freeze-dried WBB (corresponding to 253 mg anthocyanins) + 30 mL concentrated orange juice + 220 mL water (=blueberry drink)
  • vitamin C and sugars corresponding to WBB + 30 mL concentrated orange juice + 220 mg water (=placebo drink)


2) Children, which were of healthy cognitive functioning for their age. Age 7 – 10 (52 participants, 29 females and 23 males).

  • Drinks used in for children were the same as used for young adults, but the amount of water was 170 ml.
    The drinks were offered to age-groups at three occasions, separated by a minimum three-day period. Participants were guided to avoid other flavonoid-rich food before testing.    

The mood state was tested before and after drink consumption in both age-groups. The mood state was tested by using PANAS-schedule (Positive and Negative Affect Schedule, PANAS-NOW and PANAS-C for young adults and children, respectively).

Participants were asked to rate their mood sate on a five-point scale. Half of the ratings describe the positive sate of mood, and the other half negative. Thus the whole rating describes either the positive (increase, decrease, constant) or negative effect (increase, decrease, constant) of flavonoids on the mood state. Positive and negative effect on mood state reflect orthogonal facets of mood: a low positive effect is linked to depression, while a high negative effect more closely to anxiety.       

This study revealed that the positive effect of flavonoids increased in both age-groups after the consumption of flavonoid-rich drinks. However, the negative effect of flavonoids remained constant in both age-groups. This suggests that the effect of flavonoids on mood may be important to depression disorders, rather than pervasive across various mood states.  

According to previous investigations, the amount of anthocyanins is considerably higher in Finnish wild bilberry compared to lowbush blueberry used in this study. 

Khalid, S., Barfoot, K.L., May, G., Lamport, D.J., Reynolds, S.A. & Williams, C.M. Effects of acute blueberry flavonoids on mood in children and young adults. Nutrients.
2017 Feb; 9(2): 158. doi:  10.3390/nu9020158

 

 

Avainsanat:
executive function  depression  blueberry  bilberry  anthocyanins 


Back