Phytochemicals & Chemoprevention el pt

Cancer Prevention Strategies

Date: October 5, 2024

by Dr. Judith E. Fisher

Intervention Before the Event

Everyone knows that the word "chemotherapy" means using pharmaceuticals to treat cancer. But there's another important term that may be less familiar to you:  "chemoprevention,"  the use of pharmaceuticals to prevent cancer.

Of course, the continued search for cancer treatments and cures is essential, but some scientists are taking a more proactive view. Instead of focusing on the "end-game" of treating cancer; they are looking for ways to identify pre-cancerous events and conditions so they can intervene before the cancer becomes a grave concern. 

It makes perfect sense, really. If pharmaceuticals can treat invasive cancers, then it seems reasonable to assume that pharmaceuticals and other substances might also be used to stop cancer in earlier stages. That idea is the basis for chemoprevention. 

Genetics and Environment:

Cancer occurs when a gene mutates unfavorably during the process of cell division. Since cell division is continuous, human cells undergo billions of divisions in a lifetime. Indeed, the longer we live, the greater the number of cell divisions…and the greater the chance that something will  eventually "go wrong" in the process. In some people, there is a genetic (family) predisposition for this kind of aberrant cellular event. In others, the mutation may be environmentally triggered. 

Although the possible combinations of heredity and environment seem virtually infinite, it is generally accepted that "...future cancer prevention strategies will hinge on studying both genetic profiles and environmental exposures."1  The overall goal of cancer prevention research is to determine WHO is likely to develop WHAT kind of cancer related to WHICH environmental trigger. Some day we may be able to take a pill that prevents the ravages of cancer in much the same way as we now have pills to lower blood pressure or reduce cholesterol.

Glimpses of the Future - Chemoprevention

Many research studies point to factors that influence the development of cancer, and they offer us a glimpse into the potential for cancer chemoprevention. Various nutrients, phytochemicals (plant chemicals), and pharmaceuticals are already being investigated for use in chemoprevention. Here are some examples:

Nutrients may affect the development of cancer in some people.²

• Deficiencies of vitamins B12 and B6 can damage replicating DNA and damage chromosomes, sometimes causing cancer.
• A selenium deficiency may increase the incidence of epithelial cancers in some people.
• Vitamin E may lead to reduced incidences of prostrate cancer.
• Consuming some types of dietary fiber may help to prevent colorectal cancer in some people.

Some pharmaceuticals are already being investigated with regard to their potential in preventing cancer.³

• Daily low-dose aspirin may lower the risk of colon cancer in some individuals.
• Tamoxifen protects some high-risk women from breast cancer.
• Raloxifene lowers cancer risk in some healthy women.

More than 4000 phytochemicals have been identified, and scientists are exploring how they may affect cancer risk and cancer development. "Some phytochemicals act as antioxidants but may also have a role in the formation of cancer-causing chemicals and/or the suppression of cancer development."⁴   Many studies are investigating various phytochemicals and their potential for cancer prevention - for example:

• Polyphenols (catechins) in tea;
• Carotenoid (beta carotene and lycopene) in carrots and tomatoes;
• Indoles in cabbage and broccoli;
• Isoflavones in soybeans and other legumes.

Potential Cancer Preventives Source:  "Preventing Cancer" by Ricki Lewis in The Scientist, Vol 17, Supplement 2|6| September 22, 2024.
Nutrients	Pharmaceuticals	Phytochemicals
Calcium	Anti-inflammatories	Carotenoids	Indole-3-carbinol
Fiber	NSAIDs	Curcumin	Isoflavones
Folate	Chromatin modifiers	Diallyl; sulfides	Isothiocyantes
Selenium	Nuclear receptor ligands	Green tea and grape polyphenols	L-perillyl alcohol
Vitamin D		Genistein	Saponins
Vitamin E		Indole-3-carbinol	Terpines

Ongoing Research Efforts

A large number of studies have been aimed at advancing our knowledge of the causes of cancer and identifying substances that may prevent its occurrence or stamp it out in the early stages of development. The fact that the National Cancer Institute (NCI) has 60 ongoing clinical trials of chemopreventives⁵ signals the importance of chemoprevention as a proactive approach for fighting cancer.

References:

1 Ricki Lewis, "Preventing Cancer," in The Scientist, Vol 17, Supplement 2|6| September 22, 2024.
(You may register free at http://www.the-scientist.com/
and read the full article at: http://www.the-scientist.com/yr2003/sep/feature_030923.html).

2 & 3 Examples summarized from "Preventing Cancer" by Ricki Lewis.

4 "Phyto-Protect Your Health," UC Berkeley Wellness Letter, October, 2024.

5 "Preventing Cancer" by Ricki Lewis.  
___________