Omega-3 fats don’t protect against cancer, according to new research from the University of East Anglia.

The increased consumption of omega-3 fats is widespread around the world as it is widely believed to protect against or even reverse diseases such as cancer, heart attacks and strokes.

However, two systematic reviews published today show that omega-3 supplements may slightly reduce mortality and events in coronary heart disease, but may slightly increase the risk of prostate cancer. Both beneficial and harmful effects are small.

If 1,000 people took omega-3 supplements for about four years, three people would avoid dying from heart disease, six people would avoid a coronary event (like a heart attack), and three more people would develop prostate cancer.

The sister’s systematic reviews are published today in the British Journal of Cancer and the Cochrane Database of Systematic Reviews.

Omega 3 is a type of fat. Small amounts are essential to good health and can be found in the foods we eat, including nuts and seeds, and oily fish like salmon.

Omega-3 fats are also available as over-the-counter diet supplements and are widely purchased and used.

The research team looked at 47 studies in adults with no cancer, at increased risk of cancer, or with a previous diagnosis of cancer, and 86 studies with evidence of cardiovascular events or death.

More than 100,000 participants were randomized to consume more long-chain omega-3 fats (fish oils) or maintain their usual intake for at least one year for each of the ratings.

They looked at the number of people who died, were re-diagnosed for cancer, heart attacks, or strokes, and / or died from any of the diseases.

The lead author Dr. Lee Hooper of the UEA’s Norwich Medical School said, “Our previous research has shown that long-chain omega-3 supplements, including fish oils, do not protect against conditions such as anxiety, depression, stroke, diabetes or death.

“These large systematic reviews included information from many thousands of people over long periods of time. This large amount of information made it clear that if we took omega-3 supplements for several years, we could marginally reduce our risk of heart disease offsetting increase our risk of cancer. The general impact on our health is minimal.

“The evidence for omega-3s comes mainly from trials of fish oil supplements. Therefore, the health effects of oily fish, a rich source of long-chain omega-3s, are unclear. Oily fish is a very nutritious food in a balanced and balanced way Diets rich in protein and energy as well as important micronutrients like selenium, iodine, vitamin D and calcium – it’s much more than an omega-3 source.

“However, we have found that people who take omega-3 oil supplements to prevent or treat cancer have no demonstrable value. In fact, we found that they can marginally increase the risk of cancer, particularly prostate cancer.

“However, this risk is offset by a low protective effect in the case of cardiovascular diseases.

“Given the environmental concerns of industrial fishing and the impact on fish stocks and plastic pollution in the oceans, it does not seem helpful to continue taking fish oil tablets, which are of little or no benefit.”


The research was funded by the World Health Organization (WHO).

“Omega-3, Omega-6, and Dietary Polyunsaturated Fats in Relation to Cancer Incidence: Systematic Review and Meta-Analysis of Randomized Trials” was published in the British Journal of Cancer on February 29, 2020.

“Omega-3 Fatty Acids for Primary and Secondary Prevention of Cardiovascular Disease” was published on February 29, 2020 in the Cochrane Database of Systematic Reviews.

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