One of the most amazing clinical studies ever performed has been hidden away behind a paywall for more than a decade. When I first stumbled upon this clinical pearl two years ago, in the form of the publicly indexed abstract on pubmed.gov, my jaw nearly dropped.
"Pomegranate juice consumption resulted in a significant IMT [intima-media thickness] reduction, by up to 30 percent, after 1 year," reads the most eye-opening line in the study's abstract.
But what does this pomegranate-induced reduction in the intima-media thickness of the arteries mean?
The intima media is the middle portion of the arteries that becomes inflamed and fills with plaque comprised of oxidized fats, immune cells, and their debris, in the condition known colloquially as "blocked arteries," or clinically as "atherosclerosis." As the intima media grows thicker, less space is available for the blood contents to move through the opening (lumen) of the arteries. When the arteries eventually close or are blocked, catastrophic injury or death may follow.
Therefore, anything that can safely reduce, or better, reverse intima media thickening is the holy grail as far as obtaining a root cause resolution of atherosclerosis, and by implication would profoundly reduce deaths linked to cardiovascular mortality.
Indeed, in a world where the top cause of death is cardiovascular disease, and where we preemptively medicate millions more with drugs that only reduce surrogate markers for cardiovascular disease risk-i.e. lipoproteins carrying cholesterol-without showing any convincing evidence that it's reducing cardiovascular disease or all-cause mortality, how could something as simple and powerful as pomegranate be overlooked?
In fact, if a simple daily dietary intervention is capable of regressing or reversing the underlying disease process in millions of fatal cardiac cases, it would seem highly unethical not to use it.
Here, we wish to bring some of the finer details of this clinical trial to light, to further substantiate the value of botanical and food-based interventions-not only in preventing but treating major chronic disease processes such as cardiovascular disease, the developed world's most deadly disease.
Published in Clinical Nutrition in 2004 and titled "Pomegranate juice consumption for 3 years by patients with carotid artery stenosis reduces common carotid intima-media thickness, blood pressure and LDL oxidation," Israeli researchers discovered pomegranate, administered in juice form over the course of a year, reversed plaque accumulation in the carotid arteries of patients with severe, though symptomless, carotid artery stenosis (defined as 70 to 90 percent blockage in the internal carotid arteries).
The study consisted of 19 patients, five women and 14 men, aged 65 to 75, who were non-smokers. They were randomized to receive either pomegranate juice or a placebo. Ten patients were in the pomegranate juice treatment group and nine patients who didn't consume pomegranate juice were in the control group. Both groups were matched with similar blood lipid and glucose concentrations, blood pressure, and with similar medication regimens, which consisted of blood-pressure lowering (e.g. ACE inhibitors, beta-blockers, or calcium channel blockers) and lipid-lowering drugs (e.g. statins).
The 10 patients in the treatment group received 8.11 ounces (240 ml) of pomegranate juice per day, for a period of one year, and five out of them agreed to continue for up to three years.
The remarkable results were reported as follows:
"The mean intima media thickness of the left and right common carotid arteries in severe carotid artery stenosis patients that consumed pomegranate juice for up to 1 year was reduced after 3, 6, 9 and 12 months of pomegranate juice consumption by 13 percent, 22 percent, 26 percent, and 35 percent, respectively, in comparison to baseline values."
You can only imagine what would happen if a pharmaceutical drug was shown to reverse plaque buildup in the carotid arteries by 13 percent in just three months! This drug would be lauded as a life-saving miracle drug, and not only would be promoted and sold successfully as a multi-billion dollar blockbuster, but discussion would inevitably follow as to why it should be mandated.
While these results are impressive, if not altogether groundbreaking for the field of cardiology, they may be even better than revealed in the stated therapeutic outcomes above.
When one factors in that the carotid artery stenosis increased 9 percent within one year in the control group, the pomegranate intervention group may have seen even better results than indicated by the measured regression in intima media thickness alone. That is, if we assume that the pomegranate group had received no treatment, the thickening of their carotid arteries would have continued to progress like the control group at a rate of 9 percent a year, i.e., 18 percent within two years, 27 percent within three years.
This could be interpreted to mean that after three years of pomegranate treatment, for instance, the thickening of the arteries would have been reduced more than 60 percent beyond what would have occurred had the natural progression of the disease been allowed to continue unabated.
The researchers identified three likely mechanisms of action behind pomegranate's observed anti-atherosclerotic activity:
Subjects receiving pomegranate saw significant reductions in oxidative stress, including decreases in autoantibodies formed against ox-LDL, a form of oxidized low-density lipoprotein associated with the pathological process of atherosclerosis.
Decreases in oxidative stress were measurable by an increase in the blood serum enzyme paraoxonase 1 (PON1) of up to 91 percent after three years; PON1 is an enzyme whose heightened activity is associated with lower oxidative stress.
All of this is highly relevant to the question of pomegranate's anti-atherosclerotic activity because of something called the lipid peroxidation hypothesis of atherosclerosis, which assumes that it's the quality of the blood lipids (i.e., whether they are oxidized/damaged or not), and not their quantity alone that determine their cardiotoxicity/atherogenicity.
Essentially, pomegranate prevents the heart-disease-promoting effects of oxidative stress.
The intervention resulted in significant improvement in blood pressure: the patient's systolic blood pressure was reduced by 7 percent, 11 percent, 10 percent, 10 percent, and 12 percent after 1, 3, 6, 9, and 12 months of pomegranate consumption, respectively, compared to values obtained before treatment.
Pomegranate's ability to reduce systolic blood pressure indicates it has a healing effect on the endothelium, or the inner lining of the artery which fails to relax fully in heart disease; a condition known as endothelial dysfunction.
Because two of the 10 patients on pomegranate juice (after three and 12 months) experienced clinical deterioration, carotid surgery was performed and the lesions were analyzed to determine the difference in their composition to those who didn't receive pomegranate. The researchers noticed four distinct positive differences in the composition of the pomegranate-treated lesions:
1. Reduced Cholesterol Content: "The cholesterol content in carotid lesions from the two patients that consumed pomegranate juice (PJ) was lower by 58 percent and 20 percent, respectively, in comparison to lesions obtained from CAS patients that did not consume PJ."
2. Reduced Lipid Peroxides: "The lipid peroxides content in lesions obtained from the patients after PJ consumption for 3 or 12 months was significantly reduced by 61 percent or 44 percent, respectively, as compared to lesions from patients that did not consume PJ.
3. Increased Reduced Glutathione Content: "A substantial increase in the lesion reduced glutathione (GSH) content, (GSH is a major cellular antioxidant) by 2.5-fold, was observed after PJ consumption for 3 or 12 months."
4. Reduced LDL Oxidation: "LDL oxidation by lesions derived from the patients after PJ consumption for 3 or 12 months, was significantly (Po0.01) decreased by 43 percent or 32 percent, respectively, in comparison to LDL oxidation rates obtained by lesions from CAS patients that did not consume PJ."
Essentially, these results reveal that not only does pomegranate reduce the lesion size in the carotid arteries, but "the lesion itself may be considered less atherogenic after PJ consumption, as its cholesterol and oxidized lipid content decreased, and since its ability to oxidize LDL was significantly reduced."
This finding is quite revolutionary, as presently, the dangers of carotid artery stenosis are understood primarily through the lesion size and not by assessing the quality of that lesion.
This dovetails with the concept that the sheer quantity of lipoproteins (i.e. "cholesterol") in the blood can not accurately reveal whether those lipoproteins are actually harmful (atherogenic); rather, if lipoproteins are oxidized (e.g. ox-LDL) they can be harmful (or representative of a more systemic bodily imbalance), whereas non-oxidized low-density lipoprotein may be considered entirely benign, if not indispensable for cardiovascular and body-wide health.
Indeed, in this study the researchers found the pomegranate group had increased levels of triglycerides and very low-density lipoprotein, again, underscoring that the anti-atherosclerotic properties likely have more to do with the improved quality of the physiological milieu within which all our lipoproteins operate than the number of them, in and of itself.
Finally, it should be pointed out that all the patients in this study were undergoing conventional, drug-based care for cardiovascular disease, e.g. cholesterol- and blood pressure-lowering agents. Not only did the pomegranate treatment not appear to interfere with their drugs, making it a suitable complementary/adjunct therapy for those on pharmaceuticals, but it should be pointed out that the control group's condition got progressively worse (e.g. the mean IMT increased 9 percent within one year), speaking to just how ineffective drugs are, or how they may even contribute to the acceleration of the disease process itself.
Believe it or not, pomegranate has many other ways in which it can help to heal the cardiovascular system, as well as other organ systems. Our research project has identified more than 100 distinct health benefits of pomegranate.
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