The Promise of Phytochemicals

The Promise of Phytochemicals – More Than Just a Folk Remedy

You don’t need to look far to find them – those ads claiming that the cure for everything from the common cold to, yes, cancer, can be found in your kitchen cupboard. Perhaps you’ve bought into one or more of these products, and found them to be a breathless compendium of folk remedies with – perhaps – some documented studies mixed in. And maybe you’ve taken them to your doctor, with questions…

We’ve faced a number of such questions here. And we’re happy to tell you that yes, there is solid, documented evidence for the substances used in these folk remedies….but no, the prevention and cure of cancer isn’t as simple as an extra dollop of turmeric in your curry or an extra cup of green tea in the morning.

Here’s the science. The active ingredients in these remedies are called phytochemicals or phytonutrients, from the Greek phyto, meaning “plant.” Originally these compounds served as plant defense mechanisms, controlling the enzymes that balance cell metabolism and protecting against viruses, bacteria, parasites, radiation and other dangers. Animals instinctively seek out plants with these bioactive compounds, and humanity has used them for healing even before recorded history (a Neanderthal grave in Iraq contained traces of medicinal herbs, and the ancient, mummified Iceman discovered by hikers in the Tyrolean Alps was carrying antibacterial herbs in his kit).

Now, more than 10,000 phytochemicals are recognized in herbs, fruits, vegetables, nuts, and spices; in beverages such as tea, beer and wine; and in that beloved food group known as chocolate. Their medicinal impacts are equally broad, curing ailments as diverse as headaches, infection, poor digestion, and heart disease.

Because phytochemicals treat conditions that are also reflected in cancer processes, researchers are now studying the effects of phytochemicals on key cancer markers: inflammation; apoptosis; changes in cell metabolism and signaling; angiogenesis; and metastasis. Further, a large number of studies suggest that, by including certain phytochemicals in your daily diet, you can reduce the incidence of several types of cancer.

Some of the most promising anti-cancer phytochemicals appear to inhibit uncontrollable growth and reproduction of cancer cells, such as the following:

  • Curcumin – found in turmeric; may inhibit the growth of pancreatic and rectal cancer, osteosarcoma, glioma, and myeloma
  • Fucoidan –found in brown seaweed; may inhibit the growth of leukemia, stomach cancer and colon cancer
  • Genistein – found in soy-based foods; may inhibit the growth of prostate, breast, kidney, pancreatic, and bladder cancer; metastatic melanoma; osseous metastases; recurrent B-cell acute lymphoblastic leukemia; and non-Hodgkin’s lymphoma
  • Soy isoflavones – found in soy-based foods; may inhibit the growth of breast and prostate cancer
  • Epigallocatechin-3 gallate – found in green tea extract; may inhibit the growth of advanced solid tumors, breast cancer, and prostate cancer
  • Polyphenon E – found in decaffeinated green tea catechin mixture; may inhibit the growth of breast and bladder cancer; multiple myeloma; chronic and small lymphocytic lymphoma; non-small cell lung carcinoma; and monoclonal gammopathy of unknown significance
  • Lycopene – found in tomatoes; may inhibit the growth of prostate cancer
  • Resveratrol – found in grape skin, wine, peanuts, and dark chocolate; may inhibit the growth of prostate, colon, and colorectal cancer
  • Isotiocyanates – found in the Brassicaceae family of vegetables (including cabbage, broccoli, mustard greens, horseradish, and Brussels sprouts; may inhibit the growth of lymphomas, solid tumors, and ductal, epithelial, and ovarian cancer

In addition, Diindolylmethane (DIM) and its precursor, indole-3-carbinol (I3C),  also found in cruciferous vegetables such as broccoli, cabbage, and watercress; appears to selectively kill cancer stem cells.

Promising as these study results are, many questions remain: how to determine the phytochemical(s), the form, and the dosage, most effective for preventing or treating X type of cancer? Should they be used alone or in combination with chemotherapy and/or radiation? What are the benefits and possible side effects? This is the direction that current cancer research is taking.

So, you may be asking, can you prevent or treat cancer by using the foods in your fridge and kitchen cabinet? While eating healthy foods in moderation certainly can’t hurt and may help, we cannot guarantee any predictable results through independently adjusting your diet at home. There are simply too many variables.

One thing is sure, however: given the long history of phytochemicals’ effectiveness in killing cancer cells – including cancer stem cells –  it’s critical that attention and funding be directed to support research into the use of phytochemicals as the fourth modality of cancer treatment, after surgery, radiation and chemotherapy.

Paul Zhang, M.D., Ph.D.

Board-certified in Internal Medicine, Medical Oncology, and Integrative Holistic Medicine; licensed medical acupuncturist; He received medical training at Columbia University, New York, oncology training at Yale Medical School, New Haven, and a cancer research fellowship at Sloan-Kettering Cancer Institute, New York.