Aspirin and green tea may prevent cancer

Some new research suggests that vitamin A and some common household goods such as aspirin, soybeans, and green tea among, may contain certain compounds that prevent or reverse the cancer process, says James M. Spencer, MD, an associate professor and director of the division of dermatologic surgery at the Mount Sinai School of Medicine​ in New York City. The new buzzword is "chemo prevention"​ or the prevention of cancer by using substances that can inhibit or reverse the cancer process in the body. "I think in the next few years we'll be seeing many promising new candidates emerge in the fight against cancer,"​ he predicts. Vitamin A and its derivatives, also known as retinoids are one of them, Dr. Spencer says. A study of almost 2,300 people found that individuals who were considered to be at "moderate risk"​ for developing new skin cancers, and who took 25,000 international units (IU) of vitamin A orally for up to five years, were less likely to develop one less-common form of skin cancer known as squamous cell carcinoma. But a follow-up study of individuals considered to be high-risk showed no such benefit. High doses of vitamin A and its derivatives can have terrible side effects, so it is too early to make any blanket recommendations about its use. The link between diet and many types of cancer is considered controversial. But one study found that people who lowered the percentage of fat in their diet while not changing the number of calories they consumed had fewer pre-cancerous actinic keratoses, the scaly or crusty bumps that arise on the skin surface as a result of sun exposure. "Green tea has gotten a lot of research interest lately,"​ Spencer says. "It is the second most widely consumed beverage in the world, following water."​ Research suggests drinking green tea or applying it to the skin inhibits the growth of skin cancer. This effect is believed to come from a chemical found in green tea called Epigallocatechin-3-gallate (EGCG). "EGCG inhibits the growth of melanoma cells [the cells which become malignant in the most common form of skin cancer] in tissues and inhibits skin cancer in mice when applied topically or orally,"​ he says. Soybeans contain a group of compounds known as isoflavones such as genistein, which have been shown to stop the growth of tumours in mice when given orally or topically. Other research has shown it also blocks a chemical involved in the photoagoing process. Cosmetic companies are already selling products containing soybean extract. "While initial studies of these compounds have shown considerable potential as chemo preventive agents, consumers need to be aware that more testing needs to be conducted before they can be viewed as true cancer-fighting agents"​ Aspirin, Advil, and other non-steroidal anti-inflammatory drugs (NSAIDs) work by blocking the Cyclooxygenase (Cox) enzymes. "This enzyme is involved in the development of skin cancer,"​ Spencer says. When used before and during exposure to sun, NSAIDs, including the new class of so-called super aspirin can reduce skin cancer formation. "The idea that such a common group of medications so widely available may provide [to be] effective chemo prevention of cancer makes this area of research particularly exciting,"​ he says. At least one dermatologist, Kansas City-based Audrey Kunin, MD, stresses that one should not overlook the obvious things one can do, things that are known to prevent skin cancer. "The most proven things to prevent skin cancer are to cut out sun exposure and to not go in tanning beds,"​ says Dr. Kunin, founder of dermadoctor.com​. Source: WebMD​