The cancer is more likely to prove fatal than other types. It is often harder to treat than hormone-sensitive cancer.
Nearly a third of the 55,000 women in the UK diagnosed with breast cancer each year have this form. Around 11,400 women die from breast cancer in the UK every year.
A typical Mediterranean diet includes high intakes of plant-based proteins such as nuts, lentils and beans, whole grains, fish and 'healthy' monounsaturated fats such as olive oil.
Refined sugars and saturated fat are kept to a minimum.
Professor Piet van den Brandt, from Maastricht University in the Netherlands, led the study of 62,000 women over 20 years.
He said: 'Our research can help to shine a light on how dietary patterns can affect our cancer risk.
'We found a strong link between the Mediterranean diet and reduced oestrogen-receptor negative breast cancer risk among post-menopausal women, even in a non-Mediterranean population.'
Alcohol, part of a traditional Mediterranean diet, was excluded from the study because of its links to breast cancer.
It is thought almost 12,000 cases of breast cancer could be prevented in the UK each year if we stopped drinking it.
Dr Panagiota Mitrou, director of research funding at the charity World Cancer Research Fund, which paid for the study, said: 'With breast cancer being so common in the UK, prevention is key if we want to see a decrease in the number of women developing the disease.'
A Mediterranean diet only had a weak non-significant effect on the risk of hormone-sensitive oestrogen-receptor positive breast cancer, the study published in the International Journal of Cancer found.
Emma Pennery, clinical director of the charity Breast Cancer Care, said diets and other lifestyle choices do not guarantee prevention.
She added people should know the signs and symptoms and contact a GP if they are concerned.
Soy foods can also help
Women with an aggressive form of breast cancer are more likely to survive if they eat soy products such as tofu, research has shown.
Soybeans, also known as edamame beans, could reduce patients' risk of dying by 21 per cent.
The effect worked for women with oestrogen-receptor negative breast cancer, which doesn't respond to hormonal drugs.
The research, published in the journal Cancer, showed that isoflavones, chemicals found in the soybean, slowed the growth of breast cancer cells.
Contrary to previous research, soy products are also safe for women who take hormonal drugs, the study found.
/Daily Mail/
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