|International Vegetarian Union (IVU)|
act against cancer, but do they have some effect in the prevention
Atherosclerosis has been the most frequent cause of death in industrialized countries for a quite long time and much research has been carried out to find a way out of this cul-de-sac. People are still thinking of the answer in the form of pills, surgery or, what worse, in some totally irrational approaches. It is very common for us to try to find something that, maybe, does not even exist, and, at the same time, simply ignore something right under our noses or within easy reach. This is also the case of phytochemicals, abundant in all kinds of fruit and vegetables, as well as in different sorts of spices or wild herbs.
During the 1970s, great advances were made in the understanding of the role of cholesterol and, even the lay public accepts the need for reducing the increased "blood cholesterol" today. But, the cholesterol theory was not able to explain all cases of cardiovascular diseases in all circumstances. Thus, a new approach had to be used to evaluate other influences.
One of the candidates for a possible explanation of the onset of atherogenesis (the process of atherosclerosis development) is oxidation of blood lipids, namely particles called LDL - low density lipoproteins. Molecules of LDL are exposed to free radicals - other molecules which act agressively towards unstable substances like polyunsaturated fatty acids, that are part of LDL. Beside LDL, polyunsaturated fatty acids are also an important structure of every single cell membrane. That is why free radicals can damage not only LDL particles in blood, but cells of endothelium, the continuos mono-cell layer that lines the inner wall of blood vessels.
Fatty acids in LDL and/or endothelial cell membranes challenged by free radicals in reaction called lipoperoxidation are changed to lipoperoxides, that are believed to be one of atherogenesis triggering factors. Consequently, preventing LDL and membrane fatty acids from lipoperoxidation could be an effective tool in the prevention of atherosclerosis triggering. Many observations have been made already proving this theory and a lot of famous recognized barriers against lipoperoxidation come from plant foods. They are called antioxidants.
Now, the philosophy that food can be health promoting beyond its nutritional value is gaining acceptance within the public arena and among the scientific community as mounting research links diet/food components to disease prevention and treatment. Recent years were fruitful in disclosing many new chemical compounds of these foods that are of, even clinical, use for humans. Thus, not only vitamin C, tocopherols and carotenoids are accepted as strong and widely used antioxidants, but quite a number of hitherto unknown chemicals is engaging the interest of researchers, the pharmaceutical industry or the general public.
In our own research we used a non-invasive method for the detection of the very first signs of atherosclerosis - so called endothelial dysfunction. We found that middle-aged men who ate cruciferous vegetables regularly 2-times a week and more, had well-protected endothelium and the same was true for fresh fruit consumption and its influence on endothelium function. A similar influence was observed by Czech colleagues, who found a strong athero-protective effect in cabbage tissue. This athero-protection could be explained by antioxidant characteristics of some phytochemicals (e.g. certain glucosinolates - previously called thioglucosides - and S-methyl cysteine sulfoxide from cabbages, broccoli, etc.) consumed in natural food. Other antioxidant phytochemicals are flavonoids found in most fruit and vegetables, limonoids in citrus fruit or lycopene from tomatoes and water melon.
We are just at the beginning of the long way to find and define all possible phytochemicals that can have a favorable effect on humans. Nevertheless, we can enjoy this further spoon of advantage of plant-based diet by consuming plenty of strong protective agents that are our, still maybe unknown, allies in the fight against frustrating diseases of our bloodvessels.
Igor Bukovský, M.D.is.founder of the
Slovakian Veget. Society, Dep. President of the EVU, lecturer
at the University of Bratislava, author of 2 books which have
been translated into 6 languages.