Fish oils do not cut stroke risk: scientists
Supplements offer fewer benefits than previously thought but eating full meal has impact
LONDON — Fish oil supplements taken by millions for their health benefits do not reduce the risk of suffering a stroke, a new study suggests.
However, researchers said that eating oily fish at least twice a week may have a significant impact.
An analysis of studies involving almost 800,000 people in 15 countries found that there was no link between taking the capsules and a reduced risk of stroke.
Omega 3 fatty acid supplements and cod liver oil are taken by millions of people every day as it has been suggested they are good for the heart, brain and joints.
The capsules are thought to work by improving the health of blood vessels, lowering cholesterol and reducing inflammation. The market is worth at least $ 223 million.
In the latest research, scientists at Cambridge University and other institutions examined 38 studies and found that consumption of fish was associated with a reduced risk of stroke.
People eating two to four servings a week were six per cent less likely to suffer a stroke, compared with those eating less. Those eating five or more portions of oily fish had a 12 per cent lower risk.
The researchers also looked at levels of omega 3 fatty acids in the blood and found that, comparing those with the highest levels and the lowest, there was no significant difference in stroke risk. The findings suggest that nutrients other than omega 3 may be important to the health of blood vessels and that the flesh of the fish must be eaten to gain the full benefits.
Fish is high in vitamins D and B, which have been linked to healthy blood vessels, while it also contains trace minerals such as iodine, taurine and selenium.
The scientists noted that if people eat large quantities of fish each week they tend to eat less red meat and other foods that are relatively unhealthy for blood vessels. People who eat a lot of fish also tend to be healthier generally.
The study looked at people who had been diagnosed with heart disease and healthy people without it.
The researchers, writing in the British Medical Journal, also said that the apparent health benefits of oily fish over white fish may simply be down to the way it is cooked, as white- flesh fish tends to be battered and fried.