Article II continued
Toxic effects of overeating
Eating too many calories creates a dangerous state in which the bloodstream is overloaded with fat and/or sugars long after a meal is consumed. Since most people tend to overeat, they suffer from postprandial (after meal) endothelial disorders throughout most of the day.
When the blood is overloaded with fats/sugars for sustained periods, a condition known as “postprandial oxidative stress” ensues that damages the endothelium and is associated with a higher risk of atherosclerosis, obesity, and diabetes.
Scientists addressed the issue of “postprandial oxidative stress” and stated that one could mitigate the dangers by consuming polyphenols from wine, cocoa, or tea during the meal. According to these researchers, polyphenols “improve endothelial dysfunction and lower the susceptibility of LDL lipids to oxidation.” 23
These researchers attributed the benefits of polyphenols not solely to their antioxidant capacity, but also to their ability to modulate signaling molecules involved in maintaining endothelial function.23
These findings help explain why consuming a glass of red wine with a heavy meal protects against vascular disease. Since it is not practical for most people to consume red wine with every meal, consuming polyphenols from tea or chocolate during a meal would appear to be an optimal strategy to benefit from their endothelial-protecting properties.
Polyphenols in cocoa improve lipid levels
A consistent finding amongst human clinical trials is that ingestion of cocoa polyphenols modestly lowers dangerous LDL, and in some cases, significantly boosts beneficial HDL. One challenge in protecting against atherosclerosis in aging people is that their HDL levels often decline.24-27
People with high levels of HDL have low vascular disease rates. Several years ago, a major American drug company spent about $1 billion for a synthetic compound that boosted HDL. The side effect of this drug unfortunately was increased mortality and the human studies were halted. Ingestion of plant polyphenols, on the other hand, results in decreased risks of a wide range of degenerative diseases.
In a human study conducted this year, those receiving cocoa polyphenols showed an astounding 24% increase in HDL levels after twelve weeks compar-ed to only 5% in the placebo group. The cocoa polyphenol group also showed a reduced measurement of markers of oxidative stress in the body by 24%, while a measurement of LDL oxidation was lowered by 9%. The placebo group did not show improvement.28
A second human study showed that after only three weeks of consuming dark chocolate, test subjects showed an 11.4% increase in HDL levels. In the group receiving dark chocolate enriched with cocoa polyphenols, a 13.7% increase in artery-protecting HDL was observed. The white chocolate group did not show these beneficial increases in HDL, but all three groups did show a decrease of LDL oxidation by 11.9%.26
A decrease in LDL oxidation rates is a consistent finding in those who ingest cocoa polyphenols. It is the oxidation of LDL that enables this lipid to play such a significant role in the atherosclerosis process.
Very few compounds increase bene-ficial HDL. Up until now, the most effective way of boosting this artery-protecting lipid has been to use relatively high doses of niacin. The unpleasant “niacin flush” precludes most people from taking this vitamin in high enough doses. The favorable effect on HDL shown in recent studies indicates that it might be possible to tolerably increase endothelial-protecting HDL by ingesting dark chocolate and/or standardized cocoa polyphenol supplements.
Even “Normal” Blood Pressure Is Dangerously Too High
Hypertension is usually clinically defined when systolic blood pressure greater than 140 (mmHg) and diastolic pressure readings greater than 90 are found. Most doctors still consider 120/80 as normal and acceptable. A considerable amount of data reveals that keeping blood pressure below 120/80 will slash vascular disease risk. A reasonable blood pressure goal for most people in Western societies is about 115/75 mmHg.
For diabetics, achieving blood pressure levels of 115/75 mmHg or less may be particularly important to reduce the risk of progression of diabetic kidney disease to kidney failure. All aging humans benefit in the long run by maintaining a low normal blood pressure reading.
One study showed that just a slight lowering of blood pressure (from 129/78 to 124/76) led to significant reductions in arterial plaque growth, heart attack, death, and hospitalization.29
Doctors are often shocked when they learn this, having been accustomed to not diagnosing hypertension until readings of 140/90 and higher are found. To remind ourselves of what truly optimal blood pressure should be, we need only look at blood pressure levels in cultures that lack access to processed foods and engage in physical activity much of the day. People in these cultures, who rarely suffer from cardiovascular disease, have blood pressures of around 90/60 mmHg.30
A study published in the July 4, 2007, issue of the Journal of the American Medical Association (JAMA) looked at the effect of ingesting small quantities (30 mg a day) of standardized dark chocolate polyphenols compared to white chocolate.31
This 18-week study sought to ascertain if this low dose of chocolate polyphenols would reduce blood pressure and improve blood markers of endothelial dysfunction in people with untreated pre-hypertension. These individuals had blood pressure readings ranging from 130/85 to 139/89.31
The results showed that in the group receiving the dark chocolate polyphenols, hypertension prevalence declined by 20%, average blood pressure fell slightly, and blood markers of endothelial function showed sustained improvement. There were no changes in the white chocolate group.31
The magnitude of the blood pressure reductions was small (systolic declined by 2.9 and diastolic by 1.9 mmHg) in the group consuming the low doses (30 mg/day) of dark chocolate polyphenols. As the researchers pointed out, however, even these tiny reductions in blood pressure would result in lower incidences of stroke, heart attack, and all-cause mortality. More significant blood pressure reductions have been found in studies using 88 mg and greater of dark chocolate polyphenols.31
Suppressing inflammatory factors
Aging is characterized by a chronic inflammatory state that is an underlying cause of most degenerative disorders. One of the most dangerous inflammatory-inducers to the vascular system is the leukotrienes that are formed in response to excess levels of the lipooxygenase enzymes and arachidonic acid.32-40 Poor dietary choices such as over-consumption of omega-6 fats and red meat are why so many people suffer the consequences of excess leukotrienes.
The polyphenols in chocolate have been shown to reduce lipooxygenase enzymes and their pro-inflammatory byproducts (such as leukotrienes) that are so toxic to the endothelium and normal cell proliferating processes.21, 41
Epidemiological studies show that increased intake of polyphenols is associated with a reduced risk of major cardiac events. The ability of cocoa polyphenols to support endothelial function by maintaining healthy nitric oxide levels is the primary protective mechanism. The secondary benefit of suppressing dangerous inflammatory factors is another mechanism by which cocoa polyphenols may reduce cardiovascular risks.
How many cocoa polyphenols do we need?
The amount of polyphenol-containing cocoa used to make dark chocolate bars varies widely, making it difficult to obtain a consistent polyphenol dose from commercial candy products. The major problem with typical chocolate candy bars, however, is that they contain hundreds of fat and sugar calories. Intentionally adding chocolate candy to a diet already too high in calories could create as many health problems as the cocoa polyphenols help prevent.
Remember, the studies documenting the remarkable benefits of chocolate-cocoa polyphenols were relatively short term, and often used polyphenol standardized products rather than commercial, sugar-laden chocolate bars.
The encouraging news is that there are now cocoa standardized polyphenol products that are free of sugar and excess fat. Low-cost cocoa polyphenol-standardized supplements are also available.
The optimal dose of chocolate-cocoa polyphenols may be 100-130 mg a day.
Tying it all together
Arteries are the blood vessels that bear the full force of each heartbeat. Laypeople often think of arteries as flexible tubes whose only function is to carry blood that flows continuously throughout the body. In reality, arteries are dynamic, functioning muscular structures that in good health expand and contract to facilitate circulation and maintain optimal blood pressure.
Endothelial cells line the arteries, veins, arterioles, and capillaries of the vascular system. Twenty-two years ago, the endothelium was seen as a relatively inert structure that played no active role in vascular function. Since then, research has shown that the endothelium is dynamic and participates in vital aspects of arterial structure and function.42
Over the past year, Life Extension has reported on two major breakthroughs related to protecting the endothelium against age-related deterioration. The first was the remarkable ability of pomegranate to reverse clinical measurements of systemic atherosclerosis (in both carotid and coronary arteries).
The second was the finding that an SOD-enhancing nutrient (GliSODin®) also reversed a measurement of systemic atherosclerosis (as measured by carotid ultrasound).
The problem is that atherosclerosis remains the number-one cause of death and disability in the United States. Since Life Extension members take extraordinary steps to protect against atherosclerosis (and other degenerative disorders), they often find themselves reaching the outer limits of what the healthy human life span is supposed to encompass.
A typical 50-year-old human with atherosclerotic risk factors can follow relatively simple steps (such as taking fish oil, low-dose aspirin, and a statin drug if needed) to postpone a major cardiovascular event. When that same person reaches their 70s, however, the multiple lifelong pathological processes involved in endothelial dysfunction too often manifest in the form of a vascular-related disorder.
As you have learned, the endothelial cells that line blood vessels are crucial to maintaining vascular integrity. Endothelial dysfunction is a critical factor in the initiation and progression of cardiovascular disease.
Based on compelling evidence that cocoa polyphenols confer unique protective and restorative benefits to the endothelium, members should make sure that cocoa polyphenols are included as part of their daily health-promoting program.
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