Pomegranate Reverses Atherosclerosis and Slows the Progression of Prostate CancerFebruary 2007
By Dave Tuttle
Research from around the globe confirms that pomegranate is one of nature’s most concentrated sources of antioxidants.1-3 Extraordinary new findings indicate that compounds in pomegranate can do what scientists previously thought to be virtually impossible—namely, reverse the process of atherosclerosis.
These studies indicate that pomegranate confers unprecedented cardiovascular protection by restoring endothelial health, lowering blood pressure, and protecting low-density lipoprotein (LDL) from damaging oxidation. Pomegranate also appears to fight several of the most common forms of cancer, slowing the progression of prostate cancer and suppressing the growth of colon, breast, and lung cancer cells. Pomegranate even appears to shield against unsightly signs of aging by supporting the health of the skin’s underlying matrix.
The good news for consumers is that pomegranate’s remarkable health benefits can now be obtained in the form of affordable, highly concentrated extracts.
Pomegranate Enhances Nitric Oxide, Improves Endothelial Function
Pomegranate protects cardiovascular health by augmenting nitric oxide, which supports the functioning of endothelial cells that line the arterial walls. Nitric oxide signals vascular smooth muscle to relax, thereby increasing blood flow through arteries and veins. Nitric oxide reduces injury to the vessel walls, which also helps prevent the development of atherosclerosis.4
Scientists have known for some time that oxidized low-density lipoprotein (LDL) can reduce the expression of nitric oxide synthase, the enzyme that produces nitric oxide. Recently, they discovered that pomegranate juice enhances the bioactivity of nitric oxide synthase in endothelial cells.5 Furthermore, pomegranate’s antioxidant properties protect nitric oxide from oxidative destruction, thus augmenting its biological actions.6,7
An Italian study examined the role of pomegranate juice in nitric oxide synthase activity in artery sections that had already developed atherosclerosis.8 In these segments, blood forcing its way around atherosclerotic plaque buildup exerts significant stress on arterial walls. This stress reduces nitric oxide synthase expression and sets the stage for the formation of yet more plaque.
The researchers selected mice with a genetic predisposition to developing atherosclerosis. They put the mice on a high-fat diet, let arterial disease develop for six months, and then added pomegranate juice to the experimental group’s drinking water for 24 weeks. The placebo group was given plain drinking water.8
Pomegranate juice not only increased the expression of nitric oxide synthase in both healthy and atherosclerotic blood vessels, but increased it the most in blood vessels with the most plaque buildup, as shown below.8
Increase in Nitric Oxide Synthase Expression by Pomegranate
Pomegranate’s ability to increase nitric oxide synthase resulted in a significant reduction in atherosclerotic lesions:8
Reduction in Atherosclerotic Lesions by Pomegranate
In other words, in healthy parts of the blood vessels, pomegranate juice reduced lesion volume by nearly 26%, while in areas with much more plaque, pomegranate reduced the volume of lesions by approximately 20%.8 Pomegranate’s ability to enhance nitric oxide synthase and protect nitric oxide from destruction may facilitate longer-lasting concentrations of nitric oxide in endothelial cells, thus enhancing endothelial function and conferring profound cardiovascular protection.
Reversing Plaque Buildup and Lowering Heart Disease Risk
For years, scientists have believed that while antioxidants and other nutrients can slow additional atherosclerotic plaque buildup, they do little to reverse the process once plaque has already formed on the arterial walls. Now, a remarkable study from Israel indicates that pomegranate can actually reduce existing plaque formations in the arteries.
Nineteen patients from the Vascular Surgery Clinic in Haifa, Israel, were selected to participate in this three-year trial.9 All were non-smokers between the ages of 65 and 75, with asymptomatic severe carotid artery narrowing (stenosis) ranging from 70% to 90%. In other words, their arteries were so occluded by plaque buildup that only 10-30% of the original artery volume was available to permit blood flow. Ten of the 19 patients consumed 50 mL (1.7 ounces) of pomegranate juice daily, while the other nine received a placebo beverage. Both groups had similar blood pressure, cholesterol, and glucose levels at baseline, and continued their ongoing drug regimens. Dietary and lifestyle practices were kept constant during the study.
Despite the patients’ advanced atherosclerosis, ingesting pomegranate juice produced statistically significant reductions in the thickness of their carotid artery walls, which is correlated with decreased risk for heart attack and stroke. After only three months, the average thickness declined by 13%, and after 12 months, the thickness dropped 35% compared to baseline. During this same 12-month period, the average carotid artery thickness of the placebo group increased by 9%.
This study also measured various other parameters of cardiovascular health. One year of pomegranate supplementation reduced the peak systolic velocity of the blood in the carotid arteries, while systolic blood pressure itself dropped by 21%. Systolic blood pressure refers to the maximum arterial pressure when the heart beats. Pomegranate intake appears to clear so many obstructions in the carotid arteries that the blood encounters less resistance, enabling the heart to pump at a reduced pressure. Less pressure through a wider “pipe” results in less speed, or velocity.9
Pomegranate consumption did not change blood levels of glucose, LDL, or high-density lipoprotein (HDL). Standard markers of heart, kidney, and liver function, as well as homocysteine and blood cell counts, also remained unchanged.9 However, the Israeli researchers noted a number of improvements in blood markers that help to explain why pomegranate so effectively supports cardiovascular health.
For example, total antioxidant status in the blood was increased by 130% after 12 months of pomegranate use, while serum lipid peroxidation was reduced by 59%. Also contributing to the improvements was an 83% increase in serum paraoxonase-1, an enzyme that can reduce harmful lipid peroxides in arterial cells and in lipoproteins in coronary and carotid lesions.9-11 In addition, one year of pomegranate use more than doubled the time it took for the initiation of LDL oxidation, from 30 minutes to 65 minutes. Since LDL must be oxidized before it can adhere to the arterial wall, delays in oxidation and increasing levels of antioxidants in the blood keep new plaque from building up, while paraoxonase-1 may help break up existing plaque, leading to overall reductions in plaque formation over time.9
While all these one-year improvements are remarkable, some of the parameters continued to show improvement until the end of the three-year study. For example, there was a further 16% reduction in lipid peroxidation at 36 months. It appears, however, that continued use of pomegranate is required to sustain these enhancements. One month after stopping supplementation, the study participants saw their average total antioxidant status drop by 35%, while their serum paraoxonase-1 activity declined by 18%.9 As a result, pomegranate should be incorporated in a long-term program for enhancing cardiovascular health and longevity.
Another Israeli study confirmed that pomegranate reduces both systolic blood pressure and serum angiotensin converting enzyme (ACE) activity.12 After only two weeks, 50 mL of pomegranate juice daily lowered systolic pressure by 5%, while producing a 36% drop in ACE activity. Since a reduction in ACE activity has been shown to help prevent atherosclerosis independent of its effects on blood pressure, the researchers noted that pomegranate juice appears to offer broad-spectrum protection against cardiovascular disease.