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Apricot kernels are, like most nuts and seeds, very nutritious. Among the nutrients they contain is one called amygdalin, which is also known as vitamin B17. This attacks cancer cells, and thus can help prevent cancer from breaking out in our bodies.
Amygdalin (vitamin B17) is contained in many hundreds of foods, but ones that are particularly rich in amygdalin have disappeared to a large extent from our Western diet. Peoples throughout the world who still eat a traditional diet, have been found to be largely free from cancer. These diets are rich in foods containing amygdalin.
Apart from apricot kernels, examples of other amygdalin rich foods are bitter almonds (amygdalin tastes bitter - sweet almonds do not contain it), apple pips, grape seeds, millet, broad beans, and many other seeds and beans and grains - but not ones that have been highly hybridised (African orange pips contain some amygdalin, but American ones don’t, wheat is low in amygdalin).
There are many ways you can fight cancer. One is to build up the immune system so that it is very strong. Another is to supplement with antioxidants which fight carcinogens in the body. However, amygdalin seems to be unique in the way that it directly attacks cancer cells.
Amygdalin was first extracted and named over one hundred years ago and has been listed in pharmacological dictionaries since that time as being non-toxic. However it does have a poison locked away in it - one of its constituents is cyanide. But, locked into the compound amygdalin, it is chemically inert and harmless to normal living tissue. In the same way common salt (sodium chloride) is safe to eat, and in fact is necessary to the body. But this also has locked away in it a poison - chlorine. Of course if you ate too much salt at one time you would be ill. This is true of any substance, and would equally apply to apricot kernels. However, amygdalin is less toxic than salt, and less toxic than sugar.
We are told that our bodies are creating cancer cells all the time. Normally the immune system can deal with them. However at times of stress or in a particularly weak part of the body, or under extreme or regular exposure to carcinogens, then the multiplication of cancer cells may become too great for the immune system to handle. Amygdalin comes alongside the immune system and attacks the cancer cells directly. The cancer cells have within them an enzyme which unlocks the poison in the amygdalin, and in this way the cancer cells are destroyed. Normal, healthy cells do not have this enzyme. In fact they have a different enzyme which unlocks the amygdalin in a different way and releases nutrients and also a neutralising agent which would neutralise any of the poison it came into contact with. Researchers at Imperial College London have been experimenting using cyanide to kill cancer cells, and state that any poison that escaped into the bloodstream would be quickly neutralised by the liver. See ‘Researchers use cyanide’ in 'Cancer Prevention - a change in our diet'.
Amygdalin is sometimes referred to as Vitamin B17 and is found in nitriloside rich fruits and plants. In its extracted, pure, concentrated form it is known as laetrile. Laetrile is used as the main therapy, but supported by other non-toxic therapies and good nutrition, in treating cancer sufferers in some clinics.
For prevention, however, Dr Ernst T Krebs Jr., the biochemist who first produced laetrile (concentrated amygdalin) in the 1950s, recommended that if a person would eat seven to ten apricot kernels a day for life, then barring Chernobyl, he is likely to be cancer free. At the beginning of the 21st century it is expected that one in eight women in the UK will get breast cancer and one in four men prostate cancer. If other types of cancer are added in, then no family is likely to be free. Therefore the suggestion that eating 7 - 10 kernels (7gms) per day for life is likely to prevent cancer - is very good news indeed. NB  The kernels should be chewed, or ground and sprinkled on food or in fruit juice, and only five or six (1½ teaspoons ground kernels) taken at one time/in one hour.  Please also note apricot kernels may lower blood pressure.  Please also see the page 'Summary of suggestions for eating apricot kernels'Most of this information comes from World Without Cancer by G. Edward Griffin (American Media, California, 1974 and 1997). For testimonies of cancer sufferers treated with laetrile and nutrition therapy read Alive and Well (American Media, California, 1994) by Philip E Binzel, Jr., M.D. and see this website ‘Does vitamin B17 work?’.