Vitamin B17 in a nutshell:
Vitamin B17 isn’t really a vitamin at all. There have been lots of studies using B17 to treat cancer, but results have not been good. Please read this article for full details.
Best source of Vitamin B17 for Juicers
Because your body breaks it down into cyanide (a poison) we are not recommending any type of supplementation or selective juicing for this “vitamin”.
Alternative names: Vitamin B17; Laetrile (see below); amygdalin.
What Is Vitamin B17?
Apricot kernels are the source of the distinctive flavor of the Italian liqueur known as Amaretto. With chemical processing, they are also the source of a medication known a Laetrile or vitamin B17. "Vitamin" B17, however, is not really a vitamin.
Vitamin B17 is an extract from apricot kernels known as amygdalin. The seeds and kernels of all kinds of plants in the rose family (apricots, cherries, almonds, and rose seeds in particular) make amygdalin to help them create proteins when they sprout.
Even if you could eat apricot kernels whole (and you shouldn't try) your body could not digest the amygdalin they contain. To extract amygdalin, first apricot or bitter almond kernels are ground fine. They are boiled in alcohol until the liquid evaporates. Then the residue is mixed with a solvent called diethyl ether. Tiny white crystals of amygdalin precipitate at the bottom of the container.
When amygdalin is consumed by humans, enzymes in the mouth convert it into mandelonitrile, which spontaneously decomposes into two other chemicals, cyanide and benzoic acid. Cyanide, of course, is a deadly poison. Bitter almond kernels a contain an enzyme that releases cyanide before they are even ground up, but they still have to be treated with chemicals to yield amgydalin.
Amygdalin is the substance that is often called vitamin B17, even though there is nothing about the compound that is essential for human health. Technically, amygdalin has to be further processed to make the compound laevomandelonitrile, known as laetrile (a common noun) for short. The amgydalin available from clinics in Mexico is also called Laetrile (a proper noun used as an unregistered trade name).
The laetrile with the lower "l" is much more toxic than the Laetrile with the upper case "L." The Laetrile with the upper case "L" is the product offered in clinics in Mexico.
What Does Vitamin B17 Do in the Body?
As mentioned above, the moment vitamin B17 enters the body, it begins to break down to release cyanide. The process begins in the mouth and continues in the stomach. Some of the same kinds of enzymes that break down sugars in the mouth also break down amygdalin in the small intestine, and the hydrogen cyanide that is released travels quickly through the body.
Cyanide is poisonous because it disables many enzymes used in the body. Most importantly, it inhibits an enzyme known as cytochrome a3. This enzyme "recycles" electrons cells use to create an energy storage chemical known as ATP. When cells can't use pyruvate from sugar to make ATP, they transform it into lactate. This is the chemical that also accumulates when you exercise so hard that your lungs and heart can't keep up with oxygen demand.
When the body absorbs cyanide in very low doses there is just runny nose, tear production, and runny phlegm from the lungs. When the body absorbs cyanide in high doses, there is dizziness, difficult catching the breath, nausea and/or vomiting, and loss of muscle tone. Following is intense pain in the muscles. This pain reportedly resembles the burn that occurs when muscles accumulate lactic acid during heavy exercise. Asphyxiation follows even if the victim of cyanide poisoning can still breathe up until the moment of death. About 100 mg of cyanide is fatal—but it takes about 50 grams (500 times as much) amygdalin to have the same effect.
Still, why would would anyone call amygalin a vitamin?
The Theory of Selective Poisoning
The way some cancer practitioners (who may or may not be doctors) believe vitamin B17 works is by killing more cancer cells than healthy cells. This is the same idea behind the use of radiation and chemotherapy. And there is at least a little evidence that it works.
Americans are forbidden to produce or import amygdalin, so most of the research about vitamin B17 has been conducted overseas. Japanese researchers found that the compound D-mandelonitrile-beta-D-glucoside, which is what plants use to make amygdalin, activated a "suicide switch" in test tube cultures of human prostate cancer cells. It stopped the DNA in these cells from unfolding so they could not reproduce or repair themselves.
There is no plumbing in the human body that would take this compound just to cancer cells and leave healthy cells alone. However, since cancer cells multiply more rapidly than healthy cells, they are thought to die off more rapidly than their healthy counterparts. Treatment with vitamin B17 makes you sick, but it makes your cancer cells even sicker. Or at least that's the reasoning.
In the 1980's, the Mayo Clinic in Rochester, Minnesota, recruited 185 cancer patients for a study of vitamin B17 for treating cancer. Since backers of vitamin B17 treatment often claimed that the supplement would have been effective if cancer patients had not received chemotherapy, radiation, or surgery first, the study group included 60 patients who had received no other medical treatment for cancer and who gave informed consent to be treated with vitamin B17 and other nutritional supplements alone.
During the clinical trial, some of the patients showed signs of cyanide poisoning and several developed nearly lethal levels of cyanide in their bloodstreams. There was no indication that vitamin B17 reduced pain, extended life, or caused remission. The tragedy of using vitamin B17 for treating cancer is that people who used it did not get other treatments that might actually have worked, even intravenous vitamin C. After this study, the US Food and Drug Administration banned the use of vitamin B17 or Laetrile for any purpose in the United States. And treatment clinics sprang up near the border of the US and California.
Are There Any Other Uses for Vitamin B17?
As an American citizen, I can't recommend that you ever use Laetrile. It's against the law for you to bring it into the country and it's a felony for me to recommend that you do. But I can recommend that you use ground apricot pits that have not been processed into amygdalin and Laetrile when appropriate. Americans can even buy apricot pit formulas as legal patent medicines online or from Mexico.
Traditional Chinese Medicine has used apricot pits in herbal medicines for at least 2,000 years. In Chinese herbal formulas, they are used in a nearly whole state, lightly crushed and added to herbal teas. These teas are made without any chemical processing. In Chinese herbal medicines, they are usually labeled as xing ren. It's legal to use and sell apricot kernels in the US, EU, and Canada, but only in traditional herbal formulas.
Xing ren is usually used to treat dry mouth, dry throat, sore throat, lump in the throat, and laryngitis. The way the herb works may in fact be by the release of tiny amounts of cyanide, just enough to cause the throat and lungs to release more fluids. The herb may also be helpful in relieving dry constipation, but it is unfortunately not likely to be helpful for cancer.