THE EFFECT OF POMEGRANATE ON ANTHROPOMETRIC, BIOCHEMICAL, COGNITIVE AND SATIETY INDICATORS OF RISK FACTORS FOR NON-COMMUNICABLE DISEASES
Abstract
Non-communicable diseases (NCDs) such as cardiovascular, endocrine, metabolic and
cerebrovascular diseases are increasing contributors to, and major causes of worldwide
morbidity and mortality. Hypertension and obesity are the most preventable cardiovascular
risk factors which can be modified by diet and lifestyle changes.
The pomegranate, valued as a medicinal fruit since antiquity, and its extract (PE), are both
rich in polyphenol antioxidants which have the potential to improve both the management
and outcomes of chronic disease, to decrease blood pressure and increase satiety, thus
assisting in the reduction of cardiovascular disease (CVD), overweight and obesity. Chronic
pomegranate supplementation has recently been shown to improve memory retention, and
verbal memory with increased functional brain activity during visual and verbal memory
tasks. PE consumption may perform a role in enhancing cognitive performance or towards
preventing cognitive decline. The primary aims of this research were to investigate the
effects of PE on BP and stress hormones, and to explore the relationship between PE intake
and satiety, anthropometry, quality of life (QoL) and cognitive function indicators.
Four studies were conducted in healthy volunteers to fulfil these aims using double-blind,
placebo-controlled, RCT designs. The first three parallel studies were conducted over 4 and
8 weeks. The exploratory (Pom-01; n=29), satiety (Pom-01s; n=29) and blood pressure and
anthropometry (Pom-02; n=55) studies investigated the effect of PE consumption on
anthropometric, physiological, biochemical, satiety and QoL parameters. The fourth
crossover RCT (Pom-03; n=20) explored the acute effect of PE on cognitive function.
In Pom-01, paired t-tests showed that systolic BP was significantly reduced following PE
intake (4.75 mmHg; p = 0.012), with reductions in diastolic BP (1.73 mmHg; p˃0.05). Levels
of HOMA-IR (p = 0.045), glucose, insulin and uric acid all decreased. No significant changes
were recorded in volunteers taking the placebo (PL). ANOVA indicated no significant
differences between the groups. PE consumption caused a highly significant drop in salivary
cortisol levels (p = 0.016 to p<0.001), and the cortisol/cortisone ratio was also significantly
reduced (p = 0.011 to p< 0.001). The RAND 36 QoL questionnaire showed significant
improvements in physical (p = 0.018) and social functioning (p = 0.021), pain (p = 0.003),
general health (p = 0.008) and overall QoL score (p = 0.007) over the 4-week study within
the PE group compared to no significant changes in these parameters within the PL. In
Pom-01s, volunteers taking PE reported feeling less hungry, with less desire to eat, felt
fuller and more satisfied, and ate less (p = 0.05) than those who consumed the PL.
There was a significant difference between the PE and PL groups in Pom-02 for diastolic
BP (F2, 102 =4·4; p = 0·02), where PE decreased (2.79mmHg) compared to placebo. There
was a similar non-significant decrease in magnitude of SBP (2.6mmHg) compared to PL.
The QoL questionnaire, showed that significant improvements were also found in four
parameters for the PE group between baseline and 8 weeks: energy (p = 0.017), emotional
well-being (p = 0.003), social functioning (p = 0.046) and the overall QoL score (p = 0.022).
There were no significant differences in the PL group. Acute PE ingestion in Pom-03
improved aspects of cognitive performance in healthy adults (Picture Recognition, p =
0.026; overall logical reasoning reaction time (RT), p<0.001; serial subtraction, p<0.001)
compared to the non-biophenol PL.
These results suggest that PE intake could be useful for public health. It may ameliorate
non-communicable disease risk factors, reducing stress and blood pressure levels,
improving cardiovascular health, perceived health related quality of life and aspects of
cognitive function. The concurrent ability to decrease insulin resistance and modulate
indicators of satiety could be of benefit to those who suffer from diabetes (type 2), metabolic
syndrome or obesity. Future dietary intervention RCTs should focus on PE treatment effects
over time and explore the most effective dosages in different population groups, age and
body composition ranges.
Key words: Pomegranate, Pomegranate Extract (PE), Polyphenols, Antioxidants,
Anthropometry, Blood Pressure, Cholesterol, Cortisol, Diabetes, Stress, Insulin resistance,
Satiety, Quality of Life, Health, Cognitive function, Memory, Ageing, Obesity,
Cardiovascular Disease, Non-communicable diseases.