Fatty acids found in fish linked to lower risk of breast cancer

The association between omega-3 fatty acids often found in fish and various types of cancer and heart disease have been extensively studied, largely with inconclusive results.

But now, a new study meta-analysis from the British Medical Journal suggests eating one to two servings per week of oily fish, such as tuna, salmon and sardines, is associated with a 14 per cent reduced risk of breast cancer.

It's important to note that this association only exists for fish with omega-3 fatty acids.

"Our present study provides solid and robust evidence that [omega-3 fatty acids] are inversely associated with risk of breast cancer," write the authors of the study.

According to the Breast Cancer Society of Canada, 1 in 9 women will develop breast cancer in their lifetime.

Also see: Veggies that help fight breast cancer

Researcher from China reviewed and analyzed the results of 26 studies from the United States, Europe and Asia involving over 800,000 participants and over 20,000 cases of breast cancer. They looked at both dietary intake of omega-3 and how much omega-3 was found in body tissue or blood.

The researchers found that each 0.1-gram increase in omega-3 per day was linked with a 5 per cent lower risk of having breast cancer.

However, the type of omega-3 fatty acids found in nuts, seeds and leafy green vegetables did not appear to reduce the risk.

It is not clear from the results of the study whether eating fish and taking omega-3 supplements have equal benefits.

“The recommendation is really on fish consumption, not on supplements,” Veronique Chajes, an epidemiologist at the WHO’s International Agency for Research on Cancer, tells Bloomberg.

Also see: Popular drink could help prevent breast cancer from reoccurring

She concurs with the study's finding that eating omega-3 fatty acid fish once to twice a week is recommended.

The researchers also acknowledge that other compounds found in fish, such as pesticides and mercury, may reduce the protective effects of omega-3.

Dietary fat remains one of the most intensively studied dietary factors closely related with breast cancer risk.

"We do know that the factors that help reduce the risk of heart disease are the same ones that help reduce the risk of developing the risk of cancer," Dr. Deanna Attai, a breast surgeon, tells ABC.

The study was funded by the National Natural Science Foundation of China, Ministry of Education of China and National Basic Research Program of China.