Taking omega-3 supplements offers "little to no" benefit against cancer, say experts.
Consumption of fish oil supplements is promoted as having a wide range of positive impacts on health.
These are purported to include lowering the risk of strokes, as well as diseases such as cancer and dementia.
But researchers at University of Anglia (UEA) found taking daily supplements will likely have no significant impact on a person's health.
The research relates specifically to supplements, rather than omega-3 derived from eating fish, with experts still suggesting the latter is good for the heart, as well as general health.
More than 100,000 participants were randomised to either consume more omega-3 fats in supplement form, or maintain their usual intake, for at least a year.
Researchers found that if 1000 people took supplements for approximately four years, the actual effects on their health, both positively or negatively, would be minimal at best.
More about: Fishoilsupplements