In a study that appeared recently in the American Journal of Clinical Nutrition, researchers found that among 14,800 Greek women tracked for a decade, those who stuck most closely to the region's traditional diet were less likely to be diagnosed with breast cancer than those who least closely followed Mediterranean eating patterns.
The link was observed only among women who were past menopause: those with the closest adherence to the Mediterranean diet were 22% less likely to develop breast cancer during the study than those who adhered least to this style of eating.
As I wrote here recently, I believe that Mediterranean-style eating is a key component of lifestyle cancer prevention. Best of all, you don't have to live in a Mediterranean country to reap the benefits of the Mediterranean diet: this term simply describes a pattern of eating that is rich in fresh vegetables, fruits, olive oil, fatty fish, nuts, seeds, garlic, herbs and spices and relatively low in dairy and meat.
The wide variety of fresh plant foods that characterizes this diet provides a vast array of cancer-fighting compounds. These are largely absent from modern western diets which comprise a large proportion of highly processed factory foods rich in sugar, refined starches and industrially transformed vegetable oils. These types of ‘foods' are thought to provide a fertile ground for cancer cells to grow and spread.
The Mediterranean diet may be breast-cancer protective in several ways. For one, studies (this one or this one) have found that women who closely follow the diet tend to have lower levels of estrogen, a hormone that fuels the growth of the majority of breast cancers.
Moreover, cell studies conducted in laboratories (this one or this one) indicate that the fats in the Mediterranean diet - olive oil and the omega-3 fats in oily fish - may slow the growth of cancer cells.
The Mediterranean diet is also typically rich in flavonoids (in particular, flavones, flavonoids and resveratrol), substances with important antioxidant properties. Antioxidants protect body cells from free-radical damage that can eventually lead to disease, including cancer.
But why should the Mediterranean diet may offer greater protection to postmenopausal than to premenopausal women? According to the study, most younger women who develop breast cancer tend to have a genetic predisposition to the disease, whereas in older women, lifestyle and environmental factors may be more important contributors to risk.
That's not to say that younger women don't also derive benefits from Mediterranean-style eating. As far as I'm concerned, the earlier we can get healthy eating patterns in place (ideally in childhood!), the better armed we are against illness in later life - and not only cancer, but also cardiovascular disease, obesity, diabetes, fertility problems and depression.
A vast body of research going back to the 1950s suggests that the Mediterranean diet offers substantial protection against all these conditions. And when paired with other healthy lifestyle habits - regular physical activity, adequate rest, not smoking, and avoiding excessive alcohol intake - the protective effects are even greater.