Recipe For Cancer Protection?

Food compounds may help ward off tumors

Honey, rosemary, curry, and red wine may lower your risk of cancer if added to your diet. They contain a group of natural substances that inhibit activation of a gene linked to the development of pancreatic, breast, colorectal, lung, and other cancers. Curiously, the compound is similar to drugs that combat inflammation, which is not only associated with heart discase, but may also play a role in cancer.

The findings are the result of years spent studying compounds found in fruits and vegetables by Andrew Dannenberg, MD, Director of The Strang Cancer Prevention Center and Kotha Subbaramaiah, PhD, an assistant professor of medicine, at the New York Weill Cornell Medical Center.

How a gene plays a role

The gene in question is called the cyclooxygenase (or COX-2) gene. It produces an enzyme associated with cancer by promoting angiogenesis, the formation of new blood vessels that fuel a tumor's growth. The enzyme associated with the COX-2 gene may also inhibit apoptosis (the programmed death of cancer cells).

Seeking novel ways to block this enzyme's production, Dr. Dannenberg's team has investigated nearly 1,000 natural extracts which they found to have multiple anti-cancer properties. "We try to learn exactly how they affect the COX-2 gene," says Dr. Dannenberg.

His team has identified several natural compounds that deactivate the COX-2 gene. These substances are found naturally in such foods as red grapes, fish, rosemary and other herbs, and the seasoning curcumin, commonly known as turmeric.

The COX-2 deactivator in a supplement called propolis, harvested from beehives, is CAPE (caffeic acid phenetbyl ester). Propolis comes in capsules, and is used in salves, ointments, soaps, and other health care products. Honey itself--a natural source of energy--contains a wide array of vitamins, minerals, amino acids, and antioxidants.

Curious COX compounds

There are actually two types of COX enzymes: COX-1, which helps to maintain normal body functions, and COX-2 which is released with inflammation, explains Raymond Sinatra, MD, PhD, professor of anesthesiology at the Yale University School of Medicine. Conventional nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin block both COX-1 and COX-2. "COX-2 inhibitors act by selectively turning off the COX enzymes responsible for the production of prostaglandins--substances that cause pain by irritating surrounding nerves," Dr. Sinatra adds.

Several drugs, including celecaxib (Celebrex) and rofecoxib (Vioxx), are designed to relieve arthritis pain and inflammation by inhibiting the COX-2 protein. These "selective" COX-2 inhibitors cause fewer side effects than NSAIDs (although one recent study raised concern about possibly increased heart attack risk with Vioxx, because it doesn't have the anti-clotting properties of aspirin). A study in the September 2001 Lancet Oncology by Dr. Dannenberg found these drugs may also help prevent colon cancer (by reducing colon polyps). They are also being studied for preventing skin, bladder, esophagus, and oral cancers.

Natural COX-2 Inhibitors

Natural COX-2 inhibitors differ from those prescription drugs in several ways. "The agents we study prevent the protein from even forming. It's the same molecule, but at an earlier point," explains Dr. Dannenberg.

It has not yet been proven that natural COX-2 inhibitors will definitely lower cancer risk in humans, but evidence is growing. Resveratrol in red grapes, for example, slowed the growth of human breast cancer cells in the lab. In animal studies at the National Cancer Institute (NCI), curcumin prevented cancers of the skin, tongue, stomach, colon, and breast. Curcumin, as turmeric, is used in India and Southeast Asia to treat tumors, but no controlled clinical trials have been done. The University of Michigan Medical School has just begun an NCI-approved clinical trial to study how curcumin acts in humans.

Drs. Dannenberg and Subbaramaiah look forward to extending their findings to specific dietary recommendations, and expect further research to determine how much natural COX-2 inhibitors people will need to consume to reap the cancer-fighting benefits.

Their work is spearheading a new field of nutrigenomics (the effect of dietary elements on genes). So far, their research has been done only on animal models and cultured human cells. When it comes to lowering cancer risk, "Our data point to a sound, fundamental understanding of some of the benefits of fruit and vegetable consumption. The development of nutrigenomics as a field is likely to lead to dietary recommendations that may eventually be tailored to a particular individual, based on her genetic profile," Dr. Dannenberg predicts.

In the meantime, it couldn't hurt to put some of these foods on your table. They may one day prove to be real lifesavers. Carol Milano

WHAT YOU CAN EAT

The natural COX-2 inhibitors include:

  • Curcumin, from turmeric root, used in curries and mustards for color and flavor.

  • Resveratrol, found in red wine and the skin of red grapes.

  • Omega-3 fatty acids found in fish like salmon, and fish oils.

  • Retinolic acids, in vitamin A, and green or yellow fruits and vegetables.

  • Carnosol, found in rosemary.


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