Can fish oil prevent heart attack deaths?
‘Why fish oils hold all-powerful key to healthy heart’ is the headline in the Daily Express, which goes on to report, somewhat over-enthusiastically, that ‘tens of thousands of lives a year could be saved if people ate more fish’.
These wildly optimistic claims are actually based on an small experimental study involving 59 people, looking whether our genetic makeup affects how dietary fats can influence the way in which our blood vessels constrict (narrow) and dilate (widen). The question of whether eating fish gives us a healthy heart, or saves lives, was not considered by the researchers.
On two separate occasions the participants were given either a drink high in saturated fats, or a drink with some saturated fats combined with fish oils.
The researchers then used ultrasound to look at how their subjects’ blood vessels dilatated again after being briefly blocked by a blood pressure cuff.
In general, the researchers found that the response of the blood vessels varied:
- according to the drink given
- between men and women
- between people with the two different gene types known to affect blood vessel dilation
There was greater blood vessel dilatation after the drink that contained the fish oils was consumed, particularly in women with a gene type known as Asp298, which is thought to apply to around 10% of the population.
Very limited conclusions can be drawn from this study due to its size.
A healthy balanced diet and regular exercise are known to be key to good health. Whether fish oils have any particular effect on heart health cannot be answered by this study.
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