INTRODUCTION:

Vitamin B17 /Laetrile is a manmade or synthetic form of the natural substance called as amygdalin. Amygdalin is a substance found naturally in raw nuts and the pips of many fruits, particularly apricot pips/kernels. It is also present in plants such as lima beans, clover and sorghum. Some people call laetrile vitamin B17, although it isn’t a vitamin. It also has the following alternative names.^[1]

· Mandelonitrile beta D gentiobioside

· Mandelonitrile beta glucuronide

· Laevorotatory

· Purasin

· Amygdalina

· Nitriloside.^[1]

Vitamin B17 is often touted as a cancer remedy, but using Vitamin B17 for cancer treatments has not been approved by the U.S. Food and Drug Administration. The substance was added to the B-vitamin family in 1830 when it was discovered, although it is not referred to as a vitamin by nutritionists, biochemists, or scientists. There is a no recommended dietary intake allowance for amygdalin because it’s not considered an actual vitamin, but another thing to consider is that vitamin B17 sources taste bitter, so many people don’t eat them anyway. Foods rich in vitamin B17 are referred to as nitrilosides, which contain cyanide.^[2]

Since the early 1950s, both amygdalin and a modified form named laetrile have been promoted as alternative cancer treatments, often using the misnomer Vitamin B₁₇.^[3]But studies have found them to be clinically ineffective in the treatment of cancer, as well as potentially toxic or lethal when taken by mouth, due to cyanide poisoning. Neither amygdalin nor laetrile is a vitamin.^[4]

Chemistry:

Amygdalin is aCcyanogenic glycoside derived from the aromatic amino acid phenylalanine. Amygdalin and prunasin are very common among plants of the Rosaceae family, particularly the genus Prunus, Poaceae (grasses), Fabaceae (legumes) and in other food plants, including linseed and manioc. Sambunigrin, obtained from leaves of the elder tree (Sambucus Nigra), is isomeric to prunasin.^[5] Within these plants, amygdalin and the enzymes necessary to hydrolyze them are stored in separate locations so that they will mix in response to tissue damage. This provides a natural defense system.^[6]

Amygdalin is present in stone fruit pips, such as apricot (8%), peach (6%), bitter almond (5%), and plum (2.5%). Amygdalin is also found in the seeds of the apple. The stones are taken out of the fruit and cracked to obtain the kernels, which are dried in the sun or in ovens. The kernels are boiled in ethanol, on evaporation of the solution and the addition of diethyl ether; amygdalin is precipitated as white minute crystals. Natural amygdalin has the R configuration at the chiral phenyl center. Under mild basic conditions, this stereogenic center isomerizes; the S-epimer is called ‘neoamygdalin’. Although the synthesized version of amygdalin is the R-epimer, the stereogenic center attached to the nitrile and phenyl groups easily epimerizes if the manufacturer does not store the compound correctly.^[7] Amygdalin is hydrolyzed by intestinal β glycosidase, emulsin,^[8]and amygdalase to gentiobiose and L-mandelonitrile. Gentiobiose is further hydrolyzed to glucose, whereas mandelonitrile is hydrolyzed to benzaldehyde and hydrogen cyanide. Hydrogen cyanide in sufficient quantities (allowable daily intake: ~0.6 mg) causes cyanide poisoning.

Potential Benefits of Vitamin b17:

There are sayings that Vitamin B17 foods can cure cancer or at the very least put it in remission when large doses are consumed every day, but this is merely anecdotal evidence, not specific scientific evidence. The results need to be taken with caution and after researching the advantages and disadvantages. A study published in the Journal of Radiation and Biology found that amygdalin helped the immune system by increasing how many white blood cells attacked harmful cells. Those with low white blood cell counts could possibly benefit from taking B17 supplements. It may also lower blood pressure and reduce pain, but not enough research has been done to make these claims valid. There are another studies done on B17 and concluded that B17 is safe for human consumption, but the last/final line is that more research needs to be done to determine safety for both short- and long-term periods of supplementation. There is a greater chance of cyanide toxicity when B17 is taken orally and in high enough amounts, but not when it injected. The safest way to get B17 at this point is from vitamin B17 whole food sources.^[2]

· Used as an anti-cancer vitamin.

· It is an alternative treatment for cancer.

· Vitamin B17 works to reduce tumors and prevent metastasis or the spread of the cancer to other parts of the body.

· It kills cancer cells

· Strengthens the immune system

· Prevents cancer cells from developing in the future.

Sources of vitamin b17:

Foods with a high content of Vitamin B17 are called nitrilosides. They include a variety of seeds, grains and nuts and sprouts and tubers as well as leaves and beans.

Seeds of:

· Apricot

· Peaches

· Plums

· Seeds in cherries,

· Prunes and nectarines.

· Seeds in apples, grapes

· Seeds in strawberries, raspberries and blackberries, elderberries.

· Wild crabapples are high in Vitamin B17.^[9]

Grains and Nuts:

· Grains like millet, buckwheat and barley and flax are good sources.

· Nuts like bitter almonds, cashew nuts and macadamia nuts are excellent sources of Vitamin B17.^[9]

Sprouts:

· Bamboo sprout contains a high amount of Vitamin B17

· Alfalfa, fava and garbanzo and mung sprouts have medium range amounts.

Tubers:

· Yams,

· Sweet potatoes and

· Cassava.^[9]

Leaves and beans:

· Beet greens and spinach, watercress and eucalyptus.

· Beans that are good sources include black-eyed peas, black beans and green peas and lima beans, kidney beans as well as lentils.^[1]

Side Effects of Laetrile:

Laetrile contains cyanide, which is a type of poison. So the side effects of laetrile are the same as those of cyanide. These include

· Fever

· A lack of oxygen to the body tissues

· Drooping eyelids

· Sickness

· Liver damage

· Nerve damage, causing loss of balance and difficulty walking

· Headaches

· Dizziness

· A drop in blood pressure

· Confusion, coma and eventually death ^[1]

It is estimated that eating approximately 50 to 60 apricot kernels, or 50g of laetrile, can cause death. If you take laetrile as tablets, it is very important that you avoid eating other foods that contain amygdalin such as

· Raw almonds

· Nuts

· Apricots

· Peaches

· Bean sprouts

· Carrots

· Flax seed

· Celery

· High doses of vitamin C

· Crushed fruit stones or pips

· Beans – mung, lima, butter and other pulses^.[1]

Research related to vitamin B17:

A retrospective analysis study was conducted for amygdalin relevant reports using the PubMed database with the main search term "Amygdalin" or "laetrile" the author concluded that there is no convincing evidence showing that amygdalin induces rapid, distinct tumor regression in cancer patients, particularly in those with late-stage disease, is apparent. However, there is also no evidence that purified amygdalin, administered in "therapeutic" dosage, causes toxicity. Multiple aspects of amygdalin administration have not yet been adequately explored, making further investigation necessary to evaluate its actual therapeutic potential.^[10]

Randomized controlled trials and quasi-RCTs study conducted to assess the alleged anti-cancer effect and possible adverse effects of laetrile and amygdalin. The author claims that laetrile or amygdalin has beneficial effects for cancer patients are not currently supported by sound clinical data. There is a considerable risk of serious adverse effects from cyanide poisoning after laetrile or amygdalin, especially after oral ingestion. The risk-benefit balance of laetrile or amygdalin as a treatment for cancer is therefore unambiguously negative.^[11]A research study was conducted to see whether Amygdalin delays cell cycle progression and blocks growth of prostate cancer cells in vitro. Author lastly concluded that Amygdalin exhibits significant antitumor activity in both castration-sensitive and castration-resistant prostate cancer cell lines and merits further evaluation for therapeutic purposes.^[12]

A research study was conducted to determine whether amygdalin exerts antitumor effects on renal cell carcinoma (RCC) cells, its impact on RCC metastatic activity was investigated. The authors suggest that exposing RCC cells to amygdalin inhibits metastatic spread and is associated with down regulation of α5 and α6 integrin’s. Therefore, they posit that amygdalin exerts antitumor activity in vitro, and this may be linked to integrin regulation.^[13]

Implication for Nursing Practice:

Prevention is better than cure; nurses are the key member of the health care team. She/he is the one who will touch with any type of the patient oftenly in a clinical setting. Nurses must have the enough knowledge to treat and prevent diseases. Cancer is also one of the preventable diseases where nurse can play holistic role. Knowledge of nurses on vitamin B17 or Amygdalin its sources, its mechanism of action and side effects so that she can able to educate the patients and prevent many diseases including cancer in a clinical settings.

ACKNOWLEDGEMENT:

Author thanks to Mrs. Sumangala B R, Lecturer. SDM Institute of Nursing Sciences, Dharwad, Karnataka, India, for her timely support and cooperation in preparing manuscript.

CONFLICTS OF INTEREST:

None.

REFERENCES:

1. Cancer research UK. Cancer statistics reports for the UK. http://www.cancerresearchuk.org/about-cancer/cancers-in-general/treatment/complementary-alternative/therapies/laetrile

2. Dr. Alwyn Wong DC.Food and Nutrition 16^th March 2016. http://www.doctorshealthpress.com/food-and-nutrition-articles/vitamin-b17-laetrile-foods

3. Lerner IJ (1981). "Laetrile: a lesson in cancer quackery". CA Cancer J Clin. 31 (2): 91–5.

4. Lerner IJ (February 1984). "The whys of cancer quackery". Cancer. 53 : 815–9

5. Andrew Pengelly (2004), the Constituents of Medicinal Plants (2nd ed.), Allen and Unwin, pp. 44–45

6. Mora, Carlos A. Halter, Jonas G.; Adler, Cornel; Hund, Andreas; Anders, Heidrun; Yu, Kang; Stark, Wendelin J. (2016-05-11)

7. Wahab, Farooq (2015). "Problems and Pitfalls in the Analysis of Amygdalin and its Epimer". Journal of Agricultural and Food Chemistry. 63: 8966–8973.

8. George Mann, Frederick; Charles Saunders, Bernard (1975). Practical Organic Chemistry (4th Ed.). London: Longman. pp. 509–517.

9. Norma Chew, Foods Rich in Vitamin B17: Aug 16, 2013. http://www.livestrong.com/article/31231-purchase-vitamin-b17/

10. Blaheta RA, Nelson K, Haferkamp A, Juengel E.Amygdalin, quackery or cure? 2016 Apr 15; 23(4):367-76. https://www.ncbi.nlm.nih.gov/pubmed/27002407]

11. Milazzo S, Horneber M. Laetrile treatment for cancer. 2015 Apr 28 ;( 4) https://www.ncbi.nlm.nih.gov/pubmed/25918920

12. Makarević J, Tsaur I et.all Amygdalin delays cell cycle progression and blocks growth of prostate cancer cells in vitro. 2016 Feb 15; 147:137-42. https://www.ncbi.nlm.nih.gov/ pubmed/26827990]

13. Juengel E, Afschar M et.all Amygdalin blocks the in vitro adhesion and invasion of renal cell carcinoma cells by an integrin-dependent mechanism. 2016 Mar; 37(3):843-50. https://www.ncbi.nlm.nih.gov/pubmed/26781971A.

Received on 03.04.2017 Modified on 05.09.2017

Int. J. Nur. Edu. and Research. 2017; 5(4): 440-443.

DOI: 10.5958/2454-2660.2017.00094.1