If you've ever been to Greece, you know that the countryıs passion for olive oil can be overwhelming. Greek women derive a whopping 42 percent of their calories from fat, mostly olive oil. American women feel guilty when they receive 35 percent of their calories from fats of different kind.

Since fat is bad for you, Greek women should have lots more breast cancer. But in fact the breast cancer death rate in Greece is just 15.2 per 100,000, compared to 22.4 in the United States.

So Greek women are doing something right. That right thing seems to be their diet, and specifically their high intake of olive oil. Most Greek women eat traditional Mediterranean fare, including not just oil but fruit, vegetables, grains, and fish.

A large carefully controlled study in Athens recently examined the role of diet in breast cancer. It showed that a relatively high intake of fruits, vegetables, and olive oil could protect women against the occurence of this disease. Such foods were "inversely, significantly, and strongly associated" with breast cancer, according to the study by Antonia Trichopoulou and colleagues at the Athens School of Public Health. It was published in the JNCI in January (87:110-116, 1995).

These findings took some people by suprise for they suggested that it is not the intake of fat per se, but the nature and quality (and, we would add, the purity) of the fat that really matters, not just calories.

"Increased olive oil consumption was associated with significantly reduced breast cancer risk," the Greek and American scientists concluded. This finding contradicted an earlier Italian study that seemed to show a slight increase in cancer associated with all types of fat (Eur J Ca 27: 420-423, 1991).

On the other hand, one kind of fat definitely did seem related to an elevated risk of breast cancer: margarine. Japanese studies had previously shown that "a high incidence of mammary tumors was observed in rats fed a basal diet containing 20 percent margarine" (Oncology 50:201-204, 1993).

For decades, doctors have touted the wonders of margarine as the healthy fat. Consumers were encouraged to consume "polyunsaturates." Skeptics were ridiculed as "food faddists." The Greek study once again points to the value of the Mediterranean diet, with lots of whole foods, fresh produce, whole grains and, of course, olive oil.