Eating raw onion and garlic every day may reduce a woman’s risk of breast cancer, research suggests.
Scientists analyzed the dietary habits of more than 600 women in Puerto Rico, where rates of the disease have skyrocketed over the past few decades.
They found those who ate more than one serving of the onion- and garlic-based condiment sofrito a day were 67 per cent less likely to develop breast cancer.
However, consuming onions and garlic in a different form did not have the same benefits, the scientists found.
Eating onions and garlic raw may be key, with past studies suggesting their cancer-fighting antioxidants are destroyed when heated.
The study was carried out by the University of Buffalo (UB) and the University of Puerto Rico.
One in eight women in the US and UK will develop breast cancer at some point in her life, statistics show. Men can also get the disease.
Studies have suggested eating lots of onions and garlic reduces a person’s risk of lung, prostate and stomach cancer.
However, little was known about how the staple ingredients affect a woman’s breast cancer odds.
To find out more, the scientists analysed women who took part in The Atabey Study of Breast Cancer in Puerto Rico between November 2008 and June 2014.
Of the participants, 314 had battled the disease, while 346 controls had never had malignant tumours, aside from some cases of non-melanoma skin cancer.
All the women, aged 30-to-79, completed a food questionnaire that asked about their onion and garlic consumption over the past year.
It also specifically asked about how often they eat sofrito, which is widely used in Puerto-Rican cuisine.
Results revealed while there was a ‘trend toward lower breast cancer risk’ with increased onion and garlic consumption, it was not statistically significant.
However, the women who consumed sofrito every day were found to be significantly less at risk.
Onions and garlic are members of the allium plant family, along with leeks and chives.
Animal and cell studies in the laboratory have shown exposure to the allium compounds dialyl disulfide and S-allylmercaptocysteine prevents cells dividing uncontrollably.
Breast cancer is one of the most common cancers in the world. Each year in the UK there are more than 55,000 new cases, and the disease claims the lives of 11,500 women. In the US, it strikes 266,000 each year and kills 40,000. But what causes it and how can it be treated?