Biophenols can act as powerful antioxidants. Pomegranate (Punica granatum) provides a rich and varied source of biophenols with the most abundant being ellagitannins, tannins, anthocyanins, ellagic, and gallic acids. Recently, we have shown that pomegranate juice consumption may alleviate cardiovascular risk factors by reducing systolic and diastolic blood pressure and exercise-induced oxidative stress. The aim of study was to investigate the effect of pomegranate extract supplementation on salivary stress hormones and quality of life in human volunteers.
A randomized placebo controlled double blinded parallel trial was conducted. Participants (n=29; 22 females and seven males) consented to take part in the study. Age ranged from 19 to 62 years and BMI from 18.6 to 32.5 kg/m2. Each volunteer consumed either one pomegranate extract or placebo capsule of identical appearance with water after meal daily for 4 weeks. Pomegranate extract capsule (1.083 g) contains 650 mg pomegranate extract (350 mg biophenols). Dietary history, habits and the health related Quality of Life Questionnaire (Rand 36) were also recorded pre- and post-intervention. Salivary cortisol and cortisone levels (morning, noon, and evening) were also assessed by specific and sensitive ELISA methods.
Pomegranate extract intake caused a significant drop of salivary cortisol levels (morning, 39.5±19.6%, P<0.001 and noon, 43.1±32.3%, P=0.016). Salivary cortisol:cortisone ratio was also significantly reduced (morning, 1.11±0.51 to 0.55±0.26, P<0.001; noon, 1.57±0.85 to 0.75±0.72, P<0.001; and evening, 1.22±0.9 to 0.74±0.59, P=0.011). Physical (P=0.018) and social functioning (P=0.021), pain (P=0.003), general health (P=0.008), and overall Quality of Life score (P=0.007) were significantly improved in those taking the pomegranate extract capsules. There was a slight increase in salivary cortisol and cortisol:cortisone ratio in those taking the placebo.
These results suggest that pomegranate extract intake rich in biophenols reduces salivary cortisol levels and 11β-HSD1 activity, and improves health related quality of life scores. Pomegranate extract might prove to be beneficial for people suffering from chronic stress.
Angela Stockton & Emad Al-Dujaili
Queen Margaret Universty, Edinburgh, UK.
Endocrine Abstracts (2014)