New study fids stronger link between omega-3 and lower risk of cancer
WASHINGTON, August 5, 2016- Consuming omega-3 fatty acids found in oily fish like salmon, tuna, and sardines can lower the risk of developing breast cancer, according to a large-scale review of past studies published in the British Medical Journal.
The study concluded that women who consume a high level of omega-3 fatty acids from oily fish had a 14 percent lower chance of developing breast cancer than those who consumed the lowest levels.
Researchers also found a link between the amount of omega-3 fatty acids from fish consumed and the risk of breast cancer; each 0.1 gram increase of omega-3 per day was linked to a five percent lower risk of breast cancer. A regular serving of salmon, for example, contains four grams of omega-3.
Omega-3 fatty acids found in plants, however, did not seem to have the same beneficial effects in terms of lowering breast cancer risk.
The study, performed by researchers in China, analyzed and compiled data from 21 separate studies; altogether 883,585 participants, including 20,905 cases of breast cancer.
An interesting finding of the study was that while a higher intake in omega-3s from fish oil lowered the risk of breast cancer, consuming fish in general did not. In fact, the beneficial effects of consuming fish in terms of breast cancer risk were negligent among non-Asians, presumably because theses groups did not consume enough fish (and especially oily fish) to derive a measurable benefit from it.
A type of polyunsaturated fat, omega-3s have long been suspected of lowering the risk of cardiovascular disease and certain cancers. However, the link between omega-3s and lower cancer and cardiovascular disease has not been confirmed by all studies.
A 2009 review of 49 studies was unable to find a link between consuming omega-3 fats (in either supplements or through diet), and a decreased risk for cardiovascular disease or cancer. While the study did not find a positive link, authors pointed out that their conclusions did not suggest that consumers should stop eating foods rich in omega-3s.
“It’s difficult to say with any certainty which foods or dietary factors have an impact on breast cancer risk, since we all eat a variety of different foods, and our diet changes over our lifetime,” said Sally Greenbrook, Senior Policy Officer at Breakthrough Breast Cancer. “The study found that fatty acids found in fish could be associated with a lower risk of breast cancer, but there’s not enough evidence yet to suggest eating fish will reduce a person’s individual risk. However, we do recommend that all people eat a healthy balanced diet for their general health and wellbeing, of which fish can certainly form a part.”
Like many other components of healthy diets, researchers are beginning to understand that it may not be just a question of costuming omega-3 in isolation, but its interaction with other dietary components and lifestyle choices.
For example, a 2002 study found a link between women who consumed a balanced ratio of omega-3s and omega-6 fatty acids and a lower risk of developing breast cancer.
There may be also a difference between consuming oily fish as part of a healthy diet and taking fish omega-3 in the form of a dietary supplement.
“While this research reported a reduction in breast cancer risk of 14 per cent for women consuming the highest levels of a particular type of fatty acid,” said Katherine Woods, Research Information Manager at Breast Cancer Campaign. “It is important to note that body mass index (BMI) was not factored into the findings which could go some way to explaining this link.”
For now, doctors suggest that women who want to lower their individual risk of breast cancer should maintain an active lifestyle; eat a healthy diet with plenty of fruits, vegetables, and nuts; and refrain from smoking or drinking alcohol in excess.