Omega-3 fats are widely promoted as protecting people against cancer, but two recent papers dispute this notion.
Researchers at the University of East Anglia in the UK found that increasing the consumption of omega-3 fats can slightly reduce deaths from coronary heart disease but also slightly increases the risk of prostate cancer.
In the study, one thousand people took omega 3 supplements for about four years. Of the one thousand people, three died from heart disease, six people avoided a coronary event (such as a heart attack), and three extra people developed prostate cancer.
Two systematic reviews from the study were published in the British Journal of Cancer and the Cochrane Database of Systematic Reviews.
Omega-3 fats are a type of fat, and it is part of the family of polyunsaturated fats. Whereas the body can make most of the types of fats it needs, it must get omega-3 fats from food sources such as nuts, seeds, fish, vegetable oil, and leafy vegetables.
People often take omega-3 fats in over-the-counter nutrition supplements. Omega-3 fats have been touted as protecting people against cancer, heart attacks and stroke.
Minimal Health Benefits
The study consisted of 47 trials involving adults who did not have cancer, were at increased risk of cancer, or had a previous cancer diagnosis. In addition, there were 86 trials with evidence on cardiovascular events or deaths.
There were a total of over 100,000 participants. They were randomized to consume more omega-3 fats (fish oils), or to maintain their regular diet. The study duration was at least one year.
The researchers then looked at the number of people who died, had a heart attack or stroke, received a new diagnosis of cancer, and/or died of any of the diseases.
Their large systematic reviews showed that if people increased consumption of omega-3 fats, the risk of coronary heart disease is only slightly reduced, but the risk of some cancer is also slightly increased. They concluded that increased consumption of omega-3 fats had only minimal health benefits.
“But we found that there is no demonstrable value in people taking omega 3 oil supplements for the prevention or treatment of cancer. In fact, we found that they may very slightly increase cancer risk, particularly for prostate cancer,” lead author Dr Lee Hooper of the study said in their press release.
“However this risk is offset by a small protective effect on cardiovascular disease,” he added.
The researchers also added that since there is environmental impact from industrial fishing, it seems unhelpful to take fish oil tablets for omega-3 fats since there seems to be little or no health benefits.