The simple Mediterranean diet is often touted as a wonder diet - it's already been credited for reducing the risk of heart disease, and now it could help reduce the risk of a type of aggressive breast cancer.
The diet consists of lots of fruit and vegetables, nuts, extra virgin olive oil, legumes and fish, and is embraced in countries such as Greece, Italy and Spain.
Sarah Hanrahan, a Nutrition Foundation dietician, says the benefits of the Mediterranean diet are well known.
"We already know that it's good for general health, for managing obesity and for reducing heart disease."
A Dutch study examined the diets of more than 62,000 women between the ages of 55 and 69, and tracked the subjects for over 20 years.
Researchers found those who followed a Mediterranean diet were 40 percent less likely to develop "ER-Negative" breast cancer.
"That's not the most common form, but it is one of the more aggressive. So, women with ER-Negative breast cancer and in New Zealand, that's about 20-25 percent of cases. Those women have fewer treatment options," Adele Gautier, from the Breast Cancer Foundation says.
Ms Gautier says Greece has a much lower rate of breast cancer than New Zealand.
"They have about half the breast cancer incidents that we do here in New Zealand; and Greece is often touted as the place where the Mediterranean diet originated, so clearly something is working for them," she says.
While fresh food is great, it can cost more. But, Sarah Hanrahan says there's an answer.
"You can use frozen fish, frozen vegetables, you can use season vegetables and mix it up. And actually foods like nuts, seed, and legumes are actually quite affordable."
The Breast Cancer Foundation stresses there are multiple factors in diagnosis, and while this diet isn't a guaranteed way of being cancer-free, it's something to consider.