The latest British Medical Journal contains a less-than-glowing review into the health benefits supposedly delivered by the increased consumption of omega-3 fatty acids. A diet rich in omega-3 fatty acids - found in oily fish and fish oils - is thought to protect against heart disease and other cardiovascular problems. Most western health authorities encourage the public to eat more oily fish and higher amounts are advised after a heart attack, and while the researchers behind the new study do not rule out a possible beneficial effect from omega-3, they do suggest further research is warranted.
The new study was based on a meta-analysis of 89 previous studies into the health effects of both long and short chain omega-3 fats on total mortality, cardiovascular events, cancer and strokes. The results showed no strong evidence that omega-3 fats have an effect on total mortality or combined cardiovascular events.
The researchers said that several studies were contradictory in their findings, leading them to conclude that it is not clear whether long chain or short chain omega-3 fatty acids (together or separately) reduce or increase total mortality, cardiovascular events, cancer or strokes. They added that it was probably not appropriate to recommend a high intake of omega-3 fats for people who have angina, but have not had a heart attack.
While they believe that guidelines advising people to eat more oily fish should continue, they said that future reviews should be conducted regularly. They also called for more high quality randomized, controlled trials of longer duration to better understand the effects of omega-3 fats on health.
Interestingly, one researcher noted that because industrial fishing has depleted the world's fish stocks by some 90 percent, the world probably does not have a sustainable supply of long chain omega-3.
Source: British Medical Journal