Influence of dietary omega-6/omega-3 fatty acid ratio on vascular health in patients treated with statins

Randomised crossover trial of high and low dietary omega-6/omega-3 fatty acid ratios on arterial compliance, and CD11b expression in patients treated with statins

Status

Recruiting

Phases

Unknown

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12609000464268

Enrollment

Registered

2009-06-16

Start date

2007-11-21

Completion date

Unknown

Last updated

2020-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

Patients with high blood lipid levels are currently treated with dietary modification and lifestyle treatment with the addition of statins in cases where lipid levels remain elevated. Statins are the best lipid-lowering pharmaceuticals currently available; however patients treated with statins remain at high risk of cardiac events despite a marked reduction in low-density lipoprotein (LDL) cholesterol, and modest effects on triglycerides and high-density lipoprotein (HDL) cholesterol. In contrast, fish oils increase HDL-cholesterol and markedly reduce triglycerides, with little effect on LDL-cholesterol. They may therefore be ideal for combination therapy with statins to improve vascular health and reduce cardiovascular mortality. Omega-3 polyunsaturated fatty acids (PUFA) are the active ingredient in fish oil. Previous studies have demonstrated that fish oils can have beneficial effects on the vasculature and decrease the risk of coronary heart disease. The cardiac and vascular benefits of dietary omega-3 PUFA could be due to their effects on lipids, blood pressure, thrombosis, endothelial function and/or anti-arrhythmic & anti-inflammatory effects. Omega-6 PUFA are known to compete with omega-3 PUFA for many common metabolic enzymes and during incorporation into lipid fractions and membranes. This has highlighted the potential importance of the dietary ratio of omega-6 to omega-3 PUFA. This ratio may be of more importance than assessing dietary omega-3 PUFA alone. The average dietary omega-6/omega-3 ratio is between 10:1 and 17:1 in Western countries, and as high as 30:1 in certain populations. It has been estimated that the optimal dietary ratio of omega-6/omega-3 PUFA is ~1.7:1. Despite this, there is little evidence regarding the effects of the omega-6/omega-3 PUFA ratio on measures of cardiovascular health. It is important to establish whether decreasing the ratio of dietary omega-6 to omega-3 fatty acids can further improve the cardiovascular profile of patients on statins. Hypothesis That altering the dietary ratio of omega-6/omega-3 polyunsaturated fatty acids will influence vascular health – consistent with a low omega-6/omega-3 polyunsaturated fatty acid ratio diet being cardio-protective.

Interventions

a) Consumption of a diet with a low omega-6/omega-3 fatty acid ratio. b) The diet is given for 4 weeks. Observations/measures are made on day 0 and day 28. c) Dietary intake, consumed as 5 meals per day plus snacks, every day for a 4-week period; dietary ratio of omega-6/omega-3 fatty acids is 1.7:1. d) Oral (diet) 2. There is an 8-week washout period between the dietary interventions.

Study design

Allocation

Randomised controlled trial

Primary purpose

Prevention

Eligibility

Sex/Gender

All

Age

18 Years to 60 Years

Healthy volunteers

Inclusion criteria

Treated with statins

Exclusion criteria

Prior history of clinically relevant atheroma, current smokers, diabetes, obesity.

Outcome results