Licorice: Colon Cancer Conqueror

Researchers at Vanderbilt University School of Medicine in Tennessee have found that, glycyrrhizic acid a compound found in the common root spice licorice, is a powerful weapon in the fight against colorectal cancer.

Cancer of the colon is the second most common cause of cancer deaths in the USA and there are few preventive strategies available to help fight this scourge. Some reports suggest that a diet high in animal fats and proteins increases the risk for colorectal cancer; but recent evidence has refuted that theory. Other studies have shown that bioactive compounds found in plant foods such as spices may help to counter this disease. Licorice is the latest spice to be studied in this context.

Preventive drugs
One group of compounds that have shown to help prevent colorectal cancer are the non-steroidal anti-inflammatory drugs such as aspirin, ibuprofen and the cyclooxygenase (COX-2) inhibitors such as Celebrex and Vioxx. The only problem with these drugs is that they have  frequent, severe side effects such as intestinal ulceration and cardiac toxicity. Licorice on the other hand has been found to aid in the healing of ulcers by inhibiting the ulcer-causing Helicobacter bacteria.

Research
Writing in the Journal of Clinical Investigation the Vanderbilt researchers describe how glycyrrhizic acid, found in licorice, helps to prevent the formation of colon tumours by inhibiting the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2).

One of the principal pathological processes underlying cancer is inflammation; and it is the presence of too much 11βHSD2 in the colon that aggravates the inflammatory component of colorectal cancer. The anti-inflammatory drugs mentioned previously work by blocking the inflammatory process generated by the 11βHSD2 enzyme. Glycyrrhizic acid however works by blocking the 11βHSD2 enzyme itself; thereby preventing the formation of the inflammatory compounds themselves.

Other properties of Licorice
Licorice (Glycyrrhiza glabra) is a spice that has been used as both a food flavourant and a traditional medicine for thousands of years. Glycerhizin, the compound that gives licorice its sweet flavour, is a potent anti-viral agent. It is both active against HIV and protects the immune systems of those infected with the virus.

If taken to excess for long periods of time licorice may have side effects such as fluid retention and electrolyte imbalance. However these are minor when compared to those caused by non-steroidal anti-inflammatory drugs. Moreover it is unnecessary to eat large quantities of licorice in order to ward off colorectal cancer. Rather take small quantities regularly with other cancer fighting spices (such as coriander, fenugreek, garlic and mustard). Eat these with a diet rich in a variety of fruit and vegetables and you will protect your colon with foods that contain a wide range of cancer fighting phytonutrients.


References:

1) Inhibition of 11beta-hydroxysteroid dehydrogenase type II selectively blocks the tumor COX-2 pathway and suppresses colon carcinogenesis in mice and humans.
J Clin Invest. 2009 Apr;119(4):760-3   
Zhang MZ, Xu J, Yao B et al

2) Can licorice lick colon cancer?
J Clin Invest. 2009 Apr;119(4):760-3.
Stewart PM, Prescott SM.