A new open-label, randomized clinical trial has found that the risk of developing breast cancer for obese women could be reduced by omega-3 fatty acids. The trial – which was published in the journal, Cancer Prevention Research – involved 266 postmenopausal participants who all had high breast tissue density, and were either overweight, obese or a normal weight.
According to Dr. Andrea Manni, professor and division chief of endocrinology, diabetes and metabolism at Penn College of Medicine, the decreased risk could be related to the higher level of inflammation characteristic of obesity, which can lead to breast cancer. “Omega-3 fatty acids have an anti-inflammatory effect, so that’s one of the reasons why we suspected it may be particularly effective in obese women,” said Manni.
Omega-3 fatty acids are primarily found in fish oils along with select nut oils, and have been associated with a number of health benefits including lower cholesterol levels and a decreased risk of coronary heart disease. Previous studies have demonstrated a link between omega-3 fatty acid consumption and a decreased risk of breast cancer in obese women, however data seems to be inconsistent.
According to Manni, the inconsistency in results of previous studies could be related to data collected from women of a normal weight. In the current study, Manni and her team measured the changes in breast density over a two year period.
The National Cancer Institute (NCI) states that high breast density can make women four to six times more likely to develop breast cancer. “The higher the breast density, the more likely the woman will develop breast cancer,” said Manni.
All of the women participating in the current clinical trial were identified as having as breast density of 25 percent or higher. Each of the participants were randomly assigned to one of five different treatment groups: two groups received either a 60 mg or a 30 mg dose of the anti-estrogen drug Raloxifene, one group received a 4 gm dose of the prescription omega-3 drug, Lovaza, one group received 30 mg of Raloxifene along with 4 gm Lovaza, and the final control group received no treatment.
After two years of study, the researchers identified a link between increased omega-3 fatty acid levels in the blood and a reduction in breast density. This association was only shown in the 20 percent of participants who were obese. The researchers believe that the docosahexaenoic acid (DHA) in the omega-3 supplement may be responsible for reducing breast density.
“The finding supports the idea that omega-3s, and specifically DHA, are preferentially protective in obese postmenopausal women,” said Manni. “This represents an example of a personalized approach to breast cancer prevention.”