If you have ever sampled a spicy salsa or tasted a fiery curry, you have experienced capsaicin. Capsaicin is the chemical that gives hot peppers like jalapenos and serranos their heat.
What Is Capsaicin?
Capsaicin belongs to a family of organic compounds called vanilloids. Like many vanilloids, capsaicin binds to sensory neurons. This is what creates the burning sensation in your mouth when you eat hot peppers.
Now researchers have discovered that capsaicin can bind to may types of cancer cells as well, and kill them by inducing a process called apoptosis.
What is Apoptosis?
Apoptosis is often called 'programmed cell death' or 'cell suicide.' In healthy tissues, apoptosis safely eliminates damaged older cells to make room for new, healthy ones.
Cancer cells resist apoptosis. Conventional radiotherapy and chemotherapy can induce apoptosis in some cancer cells, but will also damage surrounding healthy cells. Recent research has shown that capsaicin can target cancer cells without harming healthy cells.
Cancer's 'Achilles Heel'
In 2007 the University of Nottingham announced that research had shown that capsaicin attacks the mitochondria of cancer cells. Mitochondria produce adenosine triphosphate, or ATP, a chemical that is crucial to producing energy in cells.
Dr. Timothy Bates lead the Nottingham study. Interviewed by the BBC in 2007, Dr. Bates described the discovery this way: "As these compounds attack the very heart of tumor cells, we believe that we have in effect discovered a fundamental 'Achilles heel' for all cancers."
Capsaicin Induces Apoptosis in Many Types of Cancer Cells
Research teams around the world have been investigating capsaicin's effect on different types of cancer cells.
In 2003, Japanese researchers representing three Tokyo universities found that injections of capsaicin reduced the size of leukemia tumors implanted in mice. Their findings were published in the journal Cancer Research in 2004.
In March 2006, researchers at the Samuel Oschin Comprehensive Cancer Institute at Cedars-Sinai Medical Center announced that capsaicin dramatically slowed the growth of prostate tumors implanted in mice.
In April 2006 a research team from the University of Pittsburgh School of Medicine presented evidence that capsaicin can induce apoptosis in pancreatic cancer cells. Their findings were presented at the annual meeting of the American Association for Cancer Research.
In April 2010, FASEB Journal reported that researchers at the Marshall University School of Medicine in Huntington, West Virginia had discovered that capsaicin reduced the growth of small cell lung cancer tumors in mice.
A Canadian research team at the University of Toronto has shown that capsaicin can induce apoptosis in prostate cancer cells. Their findings were published in the journal Cancer Research on April 15, 2010.
In each study, capsaicin targeted cancer cells without harming surrounding healthy tissue.
Can Eating Chili Peppers Prevent Cancer?
So far, capsaicin seems to be a promising anti-cancer weapon in the lab. Does this mean that we should begin eating chili peppers at each meal?
Not so fast, say researchers.
Josephine Querido, cancer information officer at the nonprofit agency Cancer Research UK, told the BBC in 2007: "This research does not suggest that eating vast quantities of chilli pepper will help prevent or treat cancer."
While some recent experiments involved feeding capsaicin to mice, others injected the compound directly into tumors. Currently there are no studies using human subjects. Doctors and researchers continue to recommend a balanced diet rich in fruits and vegetables to reduce cancer risk.
Salsa and curry can be part of a healthy diet, but don't expect a prescription for capsaicin just yet.
Sources
- BBC Local Nottingham(Online): "How spicy foods can kill cancers"(Staff, Jan. 2007).
- ScienceDaily.com(Online): "A curry a day keeps the doctor away"(Staff, Jan. 2007).
- Cancer Research(Online):"Induction of Apoptosis in Leukemic Cells by Homovanillic Acid Derivative, Capsaicin, through Oxidative Stress" (Keisuki Ito, et al, Feb. 2004).
- Cedars-Sinai News Release(Online): "Pepper component hot enough to trigger suicide in prostate cancer cells"(Cynthia Harding/Staff, March 2006).
- Medical News Today(Online): "Capsaicin shows promise in inhibiting growth of pancreatic cancer."(Clare Collins/Jim Swyers, April 2006).
- FASEB Journal(Online): "Capsaicin: a potential therapeutic agent for human small cell lung cancer."(Aaron M. Dom, et al, April 2010).
- Cancer Research(Online): "Abstract 5724: Capsaicin and lycopene in combination reduce proliferation and induce apoptosis in prostate cancer cells via TRPV6 mediated phenomenon"(Natalie A. Venier, et al, April 2010).
- Cancer Research UK Cancer News(Online): "Long way to go on chilli cancer-therapy, says Cancer Research UK"(Staff, March 2006).
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