Vitamin B17, also known as laetrile or amygdalin, has raised a lot of controversy among consumers and health professionals alike. This supplement has been banned by the FDA for decades, but it continues to make headlines. While it's true that you can't purchase vitamin B17, you can get it from food.
There is no such thing as "vitamin B17." Dietary supplements marketed under this name contain amygdalin and laetrile, two potentially toxic compounds.
After consumption, these substances are broken down into cyanide. There have been several cases of cyanide poisoning following the ingestion of amygdalin tablets. Seizures, abnormal heart rhythm, headache, confusion and coma are all common side effects. Ingesting as little as 50 milligrams can be fatal.
Why Is Vitamin B17 Illegal?
Apricot kernels, lima beans, bitter almonds and apple seeds have one thing in common: They all contain amygdalin. After ingestion, this bitter substance is converted to hydrogen cyanide, a chemical compound that may cause severe toxicity. As the National Cancer Institute points out, cyanide is thought to induce cancer cell death, although current evidence doesn't support these claims.
Laetrile is a synthetic form of amygdalin. This artificial compound has been used in cancer treatment since the '70s, according to a July 2018 review published in Biochemistry and Biophysics Reports. Both amygdalin and laetrile are marketed under the name vitamin B17. However, neither is an actual vitamin.
Proponents say that amygdalin may inhibit tumor growth, kill cancer cells, reduce blood pressure and increase life expectancy, among other benefits. Unfortunately, these claims lack scientific evidence. In fact, amygdalin tablets and other similar products may cause poisoning.
In August 2017, the journal Case Reports in Emergency Medicine described a case of cyanide toxicity from amygdalin supplements. A 73-year-old woman took 500 milligrams of vitamin B17 per day for pancreatic cancer. About 45 minutes after the first dose, she experienced dizziness, abnormal heart rhythm, stomach pain, confusion and other symptoms. The patient went to the ER where she received treatment.
As the researchers note, amygdalin tablets are about 40 times more concentrated than the injectable form. A vitamin B17 supplement containing 500 milligrams of this compound can have up to 30 milligrams of cyanide. Most times, 50 milligrams of cyanide are enough to kill a person. Cardiac arrest, seizures, cell death and coma are all potential side effects.
Most claims surrounding the so-called vitamin B17 lack scientific evidence.
Amygdalin is unlikely to suppress tumor growth and cure cancer, according to a April 2016 review featured in the journal Phytomedicine. More research is needed to assess its safety and therapeutic properties. The review authors also state that purified amygdalin may not cause toxicity when used in therapeutic doses.
B17 Vitamin Side Effects
The so-called vitamin B17 has no proven benefits. A few studies cited by the American Cancer Institute suggest that amygdalin may decrease tumor size and improve cancer symptoms, but its effects are temporary.
Those taking a vitamin B17 supplement may experience adverse reactions ranging from mild to severe. These include but are not limited to:
- Nerve damage
- Difficulty walking
- Low oxygen levels in the blood
- Nausea and vomiting
In severe cases, amygdalin may cause liver damage, coma and even death. The American Cancer Institute warns that eating crushed apricot kernels and fruit pits, raw almonds and certain fruits or vegetables containing amygdalin can worsen its side effects.
Crushed fruit seeds and kernels as well as some nuts are high in amygdalin and may cause poisoning.
Beware that vitamin B17 supplements may not contain pure amygdalin. These products are not regulated or approved by the FDA. They can be purchased from Mexico and online, but you don't really know what you get. Most formulas contain ingredients that come from questionable sources and may be contaminated with bacteria and mutagenic compounds.
The potential side effects of amygdalin pills are mostly related to cyanide poisoning. According to the European Food Safety Authority, ingesting 0.5 to 3.5 milligrams of hydrogen cyanide per kilogram of body weight can lead to death. Smaller doses may cause joint and muscle pain, sleep problems, fever and lethargy.
A report published in the Netherlands Journal of Medicine in November 2013 describes the case of a man who ingested 70 chopped apricot kernels daily for 45 days. His liver tests revealed high cyanide levels and abnormal liver chemistry with no signs of toxicity.
The Centers for Disease Control and Prevention states that cyanide deprives the body cells of oxygen, leading to cell death. The brain and heart suffer the most damage as they rely on oxygen to function properly. The longer you're exposed to cyanide, the greater the risks. This chemical may cause life-threatening symptoms, such as decreased heart rate, respiratory failure and unconsciousness.
Is It Worth the Risk?
Both amygdalin and laetrile pose serious health risks and can be lethal when consumed in large doses. However, this doesn't mean that swallowing a few cherry pits or apple seeds will kill you. Just make sure you don't chew or crush them. Cyanide is released when the fruit seeds or kernels are crushed or chopped.
A small number of studies do suggest that amygdalin may inhibit tumor growth. For example, a January 2016 study published in the International Journal of Molecular Medicine found that amygdalin may reduce kidney cancer cell activity and stop metastasis. However, these effects were observed in vitro (a controlled experimental environment), so it's hard to say how they translate to humans.
Based on these findings, it's unclear whether or not amygdalin protects from cancer. If you decide to try it out, consult your doctor and get regular blood tests.
Just make sure you're aware of the risks involved. Whole foods containing amygdalin can be just as harmful as supplemental vitamin B17. According to the review published in Biochemistry and Biophysics Reports, there have been several cases of cyanide poisoning due to oral ingestion of amygdalin from bitter almonds and apricot kernels. The patients experienced rapid heartbeat, seizures, loss of consciousness and severe toxicity symptoms.
- National Cancer Institute: "Laetrile/Amygdalin (PDQ®) – Patient Version"
- Biochemistry and Biophysics Reports: "Effects of the Gut Microbiota on Amygdalin and Its Use as an Anti-Cancer Therapy: Substantial Review on the Key Components Involved in Altering Dose Efficacy and Toxicity"
- Case Reports in Emergency Medicine: "Physician Beware: Severe Cyanide Toxicity From Amygdalin Tablets Ingestion"
- Phytomedicine: "Amygdalin, Quackery or Cure?"
- Cochrane Library: "Laetrile Treatment for Cancer"
- European Food Safety Authority: "Apricot Kernels Pose Risk of Cyanide Poisoning"
- Netherlands Journal of Medicine: "Cyanide Intoxication by Apricot Kernel Ingestion as Complimentary Cancer Therapy"
- CDC: "Facts About Cyanide"
- National Capital Poison Center: "I Swallowed a Cherry Pit!"
- International Journal of Molecular Medicine: "Amygdalin Blocks the in Vitro Adhesion and Invasion of Renal Cell Carcinoma Cells by an Integrin-Dependent Mechanism"
- National Cancer Institute: "In Vitro"
- NCBI: "Amygdalin Regulates Apoptosis and Adhesion in Hs578T Triple-Negative Breast Cancer Cells"
- Journal of Hygienic Engineering and Design: "Potential Benefits and Controversies Related to Use of Amygdalin (Vitamin B17)"