Health News, Does less fat equal less breast cancer? That's a question many Canadian women are asking as Dr. Norman Boyd's unique diet and breast cancer study goes into its final year. The oncologist at the Ontario Cancer Institute had a crazy idea a decade ago: Why not find thousands of women at risk of getting breast cancer, deprive them of cookies and butter and french fries, then see who gets breast cancer and who doesn't.

The idea that there might be a link between breast cancer and diet began years ago when studies showed that women in Japan, eating diets higher in carbohydrates and lower in fats than women in North America and Europe, had notably lower rates of the disease.

"When people migrate from Asia to North America, their rates change," Boyd said. "So clearly, there is something in the environment that is affecting rates. If we can identify that, and change it, then we can prevent the disease," Boyd says.

Animal experiments have also suggested dietary fat plays a role, he added. "You can modulate the frequency with which mammary tumors develop by diet in small animals."

But would the same apply to humans? To find out, Boyd and his team are following 4,700 Canadian women who are at increased risk of breast cancer; they've studied their eating patterns, compared their mammograms over the years and gathered tons of data.

The study's participants are between the ages of 30 and 65, were neither pregnant nor breastfeeding, had no previous cancers and no dietary restrictions. They were also chosen by density of their breasts: Breast tissue that shows up dense on a mammogram is thought to be at increased risk of breast cancer.

Once admitted to the study, the 4,700 were asked to either change or monitor their eating habits for a decade. Half were placed on a regular diet. Half were assigned to follow a diet where the amount of fat eaten was 15 to 20 per cent of their total caloric intake. For most of us, that would be cutting our fat intake by half -- and that's on a good day when we're not seduced by ice-cream and chocolate cake.

"We have now followed these good people for several years," says Boyd, explaining that, as the study winds down, he and his team will analyse the results according to the number of breast cancers that have shown up in each group. He has already shown that a low-fat diet reduces the density of breasts, but he hasn't made the link between diet and breast cancer prevention.

And breast cancers did develop among the women: The question is, did significantly fewer develop in the women who were on the low-fat diet? Boyd won't be giving us any early releases of his results.

While medical science has come a long way in treating breast cancers and in extending the lives of many survivors, prevention is still pretty much a mystery. Aside from the genetic forms of the disease and the fact that you can prevent a recurrence of the disease with tamoxifen, a highly toxic drug, there's very little news on the prevention front, despite millions of research dollars spent annually.

After all, how can you prevent a disease whose cause is unknown? Seventy per cent of women with breast cancer have none of the known risk factors.

So the results of Boyd's study are eagerly awaited. There is a lot of money riding on prevention, and many in the research community believe that whatever it is that causes the disease is sure to be found in the environment. As women, we want a happy prevention ending: If broccoli for breakfast every day would protect us, bring it on in bushels.