Abstract and Introduction

Abstract

Purpose: Consumption of fish oil has been shown to reduce mortality in patients with cardiovascular disease (CVD). This study aims to determine the frequency and associations of dietary fish prescribing by family physicians.
Methods: A 22-item survey mailed to randomly selected Washington State family physicians.
Results: Nearly all agreed that nutrition is important in CVD prevention (99%) and felt that they have an essential role in giving dietary advice (92%). The majority (57%) knew of fish oil's effectiveness in secondary prevention of CVD. However, only 17% of respondents were identified as high fish prescribers. Knowledge of fish oil's benefit in sudden death reduction was associated with higher fish prescribers in bivariate (P = .005) and multivariate analysis (OR = 2.77; 95th CI: 1.32 to 5.82). High fish prescribers were more likely to report having sufficient time to discuss dietary therapies in bivariate (P = .018) and multivariate analysis (OR = 1.43; 95th CI: 1.03 to 1.98).
Conclusions: Despite knowledge of fish oil's benefit and favorable attitudes toward nutritional therapy, family physicians infrequently recommend fish oils for their CVD patients. Strategies improving awareness of fish oil's effects on sudden death and reducing time barriers associated with dietary counseling should be explored further to increase recommendation of this important advice.

Introduction

Cardiovascular disease (CVD) remains the number one killer of men and women in the United States.^[1] Although the role of dietary therapy has been integral for both primary and secondary prevention of CVD, the evidence for dietary modification and its reduction of all-cause mortality is limited.^[2] The National Cholesterol and Education Program's step I and step II diets (low saturated fats, whole grain, high fruits, and vegetable diet) targets cholesterol reduction to reduce CVD.^[3] Similarly, high fruit and vegetable and lower sodium diets have been shown to reduce blood pressure.^[4,5] Despite evidence for benefits in CVD risk reduction, these diets have not yet shown all-cause mortality benefits. Recently, adoption of a Mediterranean diet has shown to reduce CVD and all-cause mortality in both primary and secondary prevention.^[6,7] The Mediterranean diet combines intake of moderate alcohol, fruits and vegetables, low to moderate amounts of fish and poultry, little red meat, and the use of olive oil as an important source of monounsaturated fats.^[8]

One specific dietary recommendation in the battle against CVD may be the increased intake of ω3 fatty acids.^[9] Fatty fish such as salmon, mackerel, and herring are the primary sources of dietary ω3 fatty acids. The role of ω3 fatty acids and, more specifically, fish oil through diet or supplementation, in secondary prevention of CVD seems to be supported by cohort studies,^[10,11] randomized clinical trials,^[12-14] meta-analysis,^[15] and systematic review.^[16] Despite a recent review finding inconclusive results,^[17] the majority of the evidence seems to support the use of fish oils in secondary prevention of CVD.

Several theories may explain fish oil's apparent benefit in CVD. Potential mechanisms have focused on fish oil's anti-inflammatory,^[18] anti-thrombotic,^[19] and potent triglyceride-lowering effect.^[20] Other studies have focused on antiarrhythmic^[21,22] properties of ω3 fatty acids in the reduction of sudden cardiac death. A large Italian study showed that 1 g of fish oil via diet or through supplementation decreased all-cause mortality by 16%-nearly all the benefit coming from reductions in sudden death.^[23] Due to the mounting evidence of the beneficial effects of ω3 fatty acids, the American Heart Association (AHA) updated its scientific statement in 2002.^[24] For patients with documented coronary artery disease, the AHA recommends 1 g of fish oil for all patients via diet or supplementation. It is unclear if physicians are making these recommendations to patients who would most benefit because no studies to date have looked at the frequency of general or fish-specific nutrition counseling by physicians for patients with known CVD. This study aims to determine the practices and associations of dietary fish prescribing among family physicians and to investigate their knowledge of fish oil supplementation and attitudes toward dietary practices.