Word from on scientific high suggesting I rid my diet of coffee, chocolate and other indulgences usually leaves a bad taste. I always remember how the myth that a high-fiber diet would help reduce the risk of colon cancer was dispelled by a series of long-term studies. One of my friends who had actually survived this particularly nasty disease was incensed about the news. "For years we were told only to eat this horrible diet and now they've discovered it doesn't make a damn bit of difference!" A couple of years later new studies found evidence linking high fiber to a reduction in colon cancer -- and then again not really. By then I'd learned my lesson -- eat according to pleasure, not peer-reviewed studies.

But the new study reported by the BBC has me eyeing the Grape Nuts with new fondness. According to a report published in the International Journal of Epidemiology, premenopausal women who ate 30 grams of fiber a day had less than half the risk of breast cancer than women who ate 20 grams. Of course, science is always in flux and who knows what the next discovery will bring, but at least this news isn't based on a few fly-by-night anecdotes. Researchers at the University of Leeds looked at the diets and medical histories of 35,792 women over the course of seven years. Among the 16,000 premenopausal women, the 257 who got breast cancer tended to have diets with more calories coming from protein and lower intakes of dietary fiber and vitamin C. The most protective forms of fiber seemed to be whole grains.

But exactly how much is 30 grams? It certainly seems like a lot. According to the study, the average Brit consumes only 12 grams a day. Even during the fiber-stops-colon-cancer craze, the recommended daily dose for Americans was 25 grams. A little BBC sidebar about how to eat enough fiber is eye-opening, not because getting enough is impossible, but because it means limiting so many foods that have become modern staples for even the so-called health conscious: bagels, French breads, pastas and muffins. In addition to getting those five portions per day of fruits and vegetables, the recommended diet seems rather chewy -- for breakfast it recommends eating a bowl of high-fiber cereal and two slices of whole-grain toast. The lunch is downright unusual: half a can of beans on whole grain bread.

Does this mean premenopausal women need to forgo croissants, pancakes and white rice forever? Not at all. Menopause may have some hidden perks, after all. According to the study, high-fiber diets had no protective effect for post-menopausal women.