CBC Marketplace: Chasing the Cancer Answer

CBC MARKETPLACE: HEALTH » CANCER
Chasing the cancer answer
Broadcast: March 5, 2006

In the next generation, the Canadian Cancer Society says almost one in two Canadians will be diagnosed with cancer. One in two.

After Marketplace host Wendy Mesley was diagnosed, she began a long and personal journey. Along the way, she came across disturbing clues about why more Canadians than ever are getting sick.

Mesley says she thought she was doing everything right. The Canadian Cancer Society touts its seven steps to health:

Those are all great tips for healthy living - but like so many other Canadians with cancer, Mesley did all of them and still got the disease. Clearly, there must be something else going on.

The real cancer story is the fact that nearly one in two of us are going to get this disease.

DOES DIET MATTER?

A low-fat diet used to be touted as a cancer-fighter. Recent studies cast that into doubt.

The research found that women who switched to a low-fat diet later in life did not see a reduced risk of breast cancer, colorectal cancer or heart disease.

For eight years, researchers in the U.S. conducted three separate studies of 48,835 women with an average age of 62 who were randomly chosen to adopt either a low-fat diet or keep eating as normal.

Simply cutting the total fat in the diet generally didn't help reduce the risk of cancer or heart disease among these women, according to the studies, which were published in the Feb. 8, 2006, issue of the Journal of the American Medical Association.

Changing diet after age 50 may not work as well as eating healthy foods earlier in life, said Mara Vitolins, a dietician who co-authored one of the papers.

But researchers say older women shouldn't give up trying to eat healthy. They say the focus should be on reducing saturated fats and trans fats found in processed foods, meat and some dairy products.

Participants in the study filled out food questionnaires but the research did not account for types of fat, and the women may not have reduced their intake by enough to see a difference, the researchers added.

Cancer can also take years to develop. While women in the low-fat group did not show a reduction in cancer incidence overall, there was a small decrease in polyps that are precursor to colon cancer.

Meanwhile, the cancer-fighting benefits of a high-fibre diet have also been called into question. A review published in December 2005 found that eating a diet high in fibre does not reduce the risk of colorectal cancer.

The idea that fibre may protect against colon cancer is based on the notion that the foods help keep us regular. By bulking up stool, it was thought that insoluble fibre like wheat bran helps waste move through faster, diluting carcinogens in the bowel.

But proof that dietary fibre from fruits and vegetables, cereals or bran reduces the risk of colon cancer has been elusive, with animal studies, population studies and randomized clinical trials showing inconsistent results.

The latest study, published in the Dec. 14 issue of the Journal of the American Medical Association, analyzed data from 13 international trials involving more than 725,000 men and women who were followed for six to 20 years. During the follow-up, 8,081 colorectal cancer cases were identified.

Researchers concluded that a diet high in fibre did not reduce the risk of colon cancer, after adjusting for age and other factors such as family history, smoking and red meat intake.

Some explain rising cancer rates as a natural outcome of our aging population; rates have increased in some elderly-onset forms of cancer. But the rates are increasing at remarkable rates among other age groups too. For instance, childhood cancers have risen over 20 per cent in 30 years.

Meanwhile, prostate cancer, non-Hodgkin's lymphoma, thyroid and testicular cancers are all increasing. All have links to environmental contaminants.

"An ounce of prevention is worth a pound of cure," says the old adage. But with so much focus on treatment, drugs and finding the ever-elusive cancer cure, prevention isn't a popular word in the cancer community.

"I can accept that I have cancer; I can't accept how common it is," says Mesley. "If it was just me, I could live with that. But the number of people getting cancer is wrong. Our failure to do better fighting this disease is wrong. I just think we need to be a little wiser about the world we are creating."