Effects of Xoçai Antioxidant Supplements on Atherosclerosis Risk Factors

Background and Introduction It has long been known that increased intake of plant products results in reduced risk of atherosclerosis and cardiovascular disease, which are the most important causes of death and disability in Western societies. This protective effect has been found to correlate with increased plasma levels of various antioxidant vitamins along with the expected increased resistance of the plasma to oxidation, and reduced evidence of oxidation of lipoproteins and other plasma components. It also has long been understood that oxidized LDL, and related lipoproteins which also contain apo B-100, are a primary driving force in the process of atherogenesis. These two facts have led to a very strong interest in developing antioxidant treatments as likely effective atheropreventive measures. This quest has taken the form of several large, long-term interventional studies, in which patients have been given purified antioxidant vitamins in an effort to reduce cardiovascular events. Surprisingly, almost without exception these interventions have failed to show any favorable effects. The cause of this paradox remains unknown, but may have resulted either from the reliance on antioxidant vitamins, rather than other antioxidant elements in the diet, or from the use of highly purified products, instead of more lightly processed food elements.

Cocoa mass (or cocoa powder in the dried form) is the edible non-fat part of the cacao bean which remains once the fatty cocoa butter has been removed. Cocoa mass or powder is a rich source of polyphenol antioxidants of the flavonoid family. The predominant flavonoids in cocoa are flavonols, including both the oligomeric proanthocyanidins (procyanidins and prodelphinidins) and the monomeric catechins and epicatechins. Recent studies have shown that chocolate preparations which are high in cocoa (and thus high in flavonol content) may have several beneficial effects on the vasculature and on various risk factors for atherosclerosis. These likely beneficial effects include:

1. Increased vascular reactivity
2. Improved arterial compliance
3. Increased HDL-C levels,
4. Decreased oxidation of LDL, and
5. Reduced insulin resistance.

Although several of these studies have compared preparations with low vs. high content of cocoa (or flavonols), only one study of which we are aware has tested effects of a source of chocolate other than a high-fat chocolate bar. Only a non-bar product can readily exclude cocoa butter and/or butterfat and thus be low in fat content. Meanwhile the relatively high fat content of a chocolate bar, even if made with high cocoa powder content (thus a "dark" chocolate bar) adds many calories to the product and may well reduce the beneficial effects of the cocoa. Apparently also, all of the preparations tested in the published studies were relatively high in sugar content, which also adds calories and may reduce the benefits of the cocoa.

In addition there are many inconsistencies among studies of standard chocolate preparations regarding the above-mentioned beneficial effects (for example, studies failing to show lipid or anti-inflammatory effects), and these inconsistencies may relate to various issues. First, of all the elements in chocolate-containing foods, cocoa mass or powder appears to contain virtually all of the antioxidant factors. Variability in cocoa powder content, or possible blunting of its benefits by the addition of variable amounts of cocoa butter might variably reduce the beneficial effects. Second, the alkaline processing of cocoa (which is routine for virtually all bar and powdered chocolate products) may reduce its antioxidant content and activity. Thus, the variability in published results among various chocolate preparations could be due to differences in the degree and type of processing of the cocoa (and resulting differences in its antioxidant content), and/or differences in the presence of other components (such as fat and/or sugar) which might block beneficial effects of the cocoa.