Many traditional schools of medicine are of the opinion that the body accumulates toxins that are absorbed from the food we eat, the air we breathe, and in general, from our environment. It is thought that these accumulated toxins lead to a range of health problems, from minor conditions such as indigestion to major illnesses such as cancer. According to these schools of thought, regular blood purification and detoxification treatments are necessary to cleanse the body of these toxins and keep it healthy. Fasting is one way in which this purpose is achieved, and another is by eating certain foods. Generally, leafy vegetables (and juice prepared from these vegetables) is supposed to be good for purifying the blood. Carrot, beet, bitter gourd, and wheatgrass are also supposed to be good blood cleansers. Consumption of these foods usually follows a period of fasting, which is also supposed to help cleanse the body.
However, there is no scientific evidence for any such theory of disease and toxins, and no recorded benefit of blood purification and detoxification treatments. These are essentially pre scientific ideas that were formulated before we developed the rigorous methods of testing and verification that are used today. We now know how disease develops, and are aware that there are numerous different mechanisms at work, and all diseases cannot be traced to some simple, common factor such as toxins. In fact, the toxins that are spoken of so often by traditional and alternative medicine have never been clearly defined or detected. The idea of toxins is extremely vague and inconsistent, and the precise manner in which these toxins are supposed to cause disease has never been explained satisfactorily.
There is no doubt that the foods mentioned earlier are good for you – however, this is not because of any purification properties that they have, but because of the nutrients they provide. These foods are rich sources of fiber, which is very important for digestion, as well as of various minerals and vitamins, which the body needs for various processes. Purification of the blood occurs through natural processes – this is what the kidney and the liver are for. There are also other metabolic processes at work that process and get rid of harmful substances from the body. Your body requires help only if these organs and processes are somehow compromised – and in this case, simply fasting and eating certain foods is extremely unlikely to be enough.
answered by G M