New research suggests that fish oil may not be for everyone — it may
cause more harm than good in some people.

A study found that eating fish more frequently is associated with a
higher risk of developing atrial fibrillation or AF, the most common type
of irregular heartbeat.

Researchers analysed data collected from more than 17,000 healthy male
doctors in the Physicians' Health Study. The doctors gave details of
their fish consumption in 1983, and 15 years later, reported whether they
had developed AF.

After adjusting the data for multiple risk factors for cardiovascular
disease and lifestyle habits, researchers found that men who ate fish
more than five times a week were 61 per cent more likely to develop AF as
compared to those who ate fish once a month.

Eating fish rich in omega-3-fatty acids may have different effects on the
heart's electrical function, according to the study titled Relationship
Between Fish Consumption and the Development of Atrial Fibrillation in
Men.

Study author, Dr Anthony Aizer from the New York University Medical
Centre, was quoted as saying that it is possible omega-3 fatty acids may
actually promote the development of AF in younger people but prevent it
in older people who have other medical conditions.

Typically, cells in our heart emit electric signals causing it to
contract and pump blood to the different parts of our body. For the heart
to function properly, its two upper and two lower chambers must beat in a
consistent way. In AF, the upper chambers of the heart beat irregularly,
affecting blood flow to the heart muscle and body.

The condition itself is not life threatening. But the irregular beating
of the upper chambers may cause a blood clot to form, which may dislodge
and block an artery in the brain, leading to a stroke.

The American Heart Association's website states that if you have AF, your
chances of suffering a stroke are five times higher.

AF is more commonly seen in old age. About 10 per cent of those above 80
years old will have the condition either intermittently or continuously,
said Dr Antono Sutandar, consultant cardiologist, Raffles Hospital.

He said: "The study just confirms that many supplements we take in our
quest to become 'immortal' has minimal or no proven benefit."

Besides increasing HDL, or good cholesterol, and decreasing triglycerides
level, there is not much evidence that taking fish oil supplements helps,
he said.

Mr Geoffrey Gui, a dietitian at Alexandra Hospital recommended that we
should still include the essential omega-3 fatty acids in our diets as
their many health benefits far outweigh the inconclusive evidence
surrounding AF and omega-3s.

He said: "The relationship between diet and disease is a complex
interaction of many different risk factors and is unlikely to stem from a
specific nutrient alone."

A healthy balanced diet rich in fruit and vegetables, moderate meat and
fish and avoiding deep-fried food is probably your best bet for a long
and healthy life, said Dr Sutandar.