APPLIANCE OF SCIENCE Examining the science and commercial applications of natural bioactives Pomegranate: squeezing more from the fruit
In the November 2004 issue, this column described the vascular response-modifying effects of the juice of the pomegranate (Punica granatum) in animals and humans.
Since then, a new wave of pre-clinical and clinical evidence has emerged.
A study conducted at the Preventive Medicine Research Institute in California, led by Dr Dean Ornish (a 2005 Nutracon speaker) enrolled 45 patients with documented coronary heart disease and stress-inducible cardiac ischemia (impaired blood flow) and assigned them to receive either 240ml of POM Wonderful variety pomegranate juice (PJ; 26 patients) or a sensory- and energy-matched variant of a commercial drink (19 patients).1
After three months, the measure of stress-induced ischemia improved by 17 per cent in the PJ group while declining in the placebo group by 18 per cent, a statistically significant difference. Additionally, episodes of angina were halved in the PJ group, although this was not statistically significant, despite increasing in the placebo group. Similar to results from longer-term studies, blood triglycerides increased non-significantly (15 per cent). No changes in blood pressure were noted.
In an open-label (no placebo control) study, 26 type 2 Iranian hyperlipidaemic diabetics, not using lipid-lowering medications, were asked to consume 40g/day of concentrated PJ (Nariran Inc, Teheran).2
Dietary intakes were captured in an eight-week run-in period prior to eight weeks of PJ supplementation. Compliance with supplementation was reinforced by contact with each subject every five days and by a record card that patients were asked to fill out each time they consumed PJ.
No dietary changes in flavonoid-rich foods or beverages were noted in the two eight-week intervals. Modest but statistically significant decreases in blood total (6 per cent) and LDL (10 per cent) cholesterol were observed, with no changes in blood triglycerides.
Chronic obstructive pulmonary disease (COPD) is marked by significant oxidative stress, and is ranked fifth on the global scale of all-cause mortality, and third among those over 60 years old.3 Spanish researchers enrolled 30 men over the age of 60 with COPD and randomised them to receive 400ml PJ (pilot production; Mollar de Albatera variety) or an orange-flavoured placebo beverage.4
During a two-week run-in period and during the five-week intervention period, subjects were required to restrict from their diets ellagitannin, chocolate, nuts and pomegranate. Frequent monitoring of the blood and urine from the subjects confirmed compliance to the diet and PJ-supplementation via the presence of ellagic acid (a constituent in PJ) metabolites in the PJ group only.
No changes in any biochemical markers of oxidative stress (isoprostane), clinical chemistry, pulmonary function, or blood oxygenation were found.
The anti-cancer promise of PJ has been explored in several animal models. A recent study undertook an exploration of its efficacy in human prostate cancer.5 Forty-eight men with recurrent prostate cancer ingested 227ml (7.57oz) PJ (POM Wonderful) daily for two years, following completion of chemotherapy or surgical treatment for pre-existing prostate cancer. The duration of time required to lead to a doubling of serum Prostate Specific Antigen (PSA) was almost doubled: 14 months to 26 months.
All of the subjects displayed urinary metabolites of PJ phenolics, while blood from the subjects displayed anticancer activity against a human-derived prostate cancer cell line. Although this was described as a ?phase II study,? no placebo control group was described.
Collectively, this data augments the promise of PJ in various clinical disease states but warrants more rigorous design and even comparisons against the PJ derived from different pomegranate cultivars
Anthony Almada, MSc, is president and chief scientific officer of IMAGINutrition Inc. Respond: email@example.com
1. Sumner MD, et al. Effects of pomegranate juice consumption on myocardial perfusion in patients with coronary heart disease. Am J Cardiol 2005; 96:810-4.
2. Esmaillzadeh A, et al. Concentrated pomegranate juice improves lipid profiles in diabetic patients with hyperlipidemia. J Med Food 2004; 7:305-8.
3. World Health Organization. World Health Report 2002. www.who.int/whr/
4. Cérda BJ, et al. Pomegranate juice supplementation in chronic obstructive pulmonary disease: a 5-week randomized, double-blind, placebo-controlled trial. Eur J Clin Nutr (in press).
5. Pantuck AJ, et al. Phase II study of pomegranate juice for men with rising PSA following surgery or radiation for prostate cancer. J Urol 2005; 173 (Suppl. S):225-6.