Daily supplements of the omega-3 acids may have a beneficial effect on blood pressure. (Photo: Stock File/FIS)
Omega-3 may improve blood pressure
Tuesday, September 28, 2010, 15:30 (GMT + 9)
Scientists have found that supplements of omega-3s EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) taken daily may improve blood pressure levels in slightly overweight male teenagers.
A blood pressure fall of 3 mmHg was seen in overweight boys experiencing their adolescent growth spurt after 16 weeks of consuming omega-3 fortified bread, said Copenhagen University and the Technical University of Denmark.
“A blood pressure decrease of about 3 mmHg corresponds to a [greater than] 15 per cent reduction in the risk of stroke at a whole population level in adults,” the scientists wrote in The Journal of Pediatrics.
“Blood pressure has been shown to track into adulthood, with children and adolescents with high blood pressure more likely to suffer from hypertension later in life. Thus, adolescents with blood pressure in the higher range can be viewed as ‘prehypertensive,’ but whether the tracking of high blood pressure is a result of unhealthy diet and exercise habits carried from childhood to adulthood or whether some programming of blood pressure occurs during adolescence is not known,” they added.
Since it was first documented in the early 1970s, polyunsaturated fatty acids (PUFAs) have been tied to improved blood lipid levels, a lower tendency of thrombosis, blood pressure and heart rate improvements and better vascular function.
Omega-3 fatty acids, especially EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), have also been linked to various health benefits, such as lowered risk of certain cancers, joint health and improved behaviour and mood.
The new study involved 78 mildly overweight adolescent boys aged 13-15.
“We chose to recruit slightly overweight boys, because we wanted clear potential for improvement in the risk factors evaluated,” said the researchers.
The boys were randomly assigned to take a supplement of 1.5 g of omega-3 fatty acids per day or a vegetable oil control for 16 weeks. The oil was put into bread.
After 16 weeks, the researchers found a notable rise in EPA and DHA levels in the red blood cells of the omega-3 group of 1.2 and 6.7 per cent, respectively, versus jumps of 0.6 and 4.1 per cent in the control group.
Further, systolic blood pressure fell by 3.8 mmHg and diastolic blood pressure was 2.6 mmHg lower in the omega-3 group.
No blood level changes of triacylglycerol or insulin sensitivity were determined.
Rises in HDL and non-HDL cholesterol levels were seen as well in the omega-3 group of 5 and 7 per cent, respectively, against 2 and 0 per cent in the control group.
“In this study, the non- HDL/HDL ratio, which is believed to be a better indicator of risk, was unaffected by the treatment, and thus the net effect appears to be neutral,” added the researchers.
The researchers noted the competition between EPA/DHA and arachidonic acid (AA) in the synthesis of inflammation-related eicosanoids to justify the benefits: AA derivatives could stimulate blood vessel constriction, which would boost blood pressure, while EPA/DHA derivatives may hamper this pathway.
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By Natalia Real