Dietary Linoleic Acid for Secondary Prevention of Coronary Heart Disease and Death in the Sydney Heart Study: an RCT

National Institutes of Health Clinical Center (CC)

Status: Completed

Conditions: Coronary Heart Disease

Treatments: Other: Safflower oil

Study type: Interventional

Funder types: NIH

Identifiers

NCT01621087

NIHCC-E5744

Details and patient eligibility

About

The substitution of polyunsaturated fatty acids (PUFA) for saturated fatty acids (SFA) is a cornerstone of worldwide dietary advice for coronary heart disease (CHD) risk reduction. However, clinical CHD benefits specific to the omega-6 PUFA linoleic acid (LA), and distinct from omega-3 PUFAs, have not been established. The Sydney Diet-Heart Study (SDHS; 1966-1973) was a randomized controlled secondary CHD prevention trial testing whether selectively increasing omega-6 LA from safflower oil in place of SFA reduced CHD and improved survival. A full analysis of mortality outcomes has not been published. The investigators recovered the original SDHS dataset, which included detailed longitudinal dietary, smoking and coded mortality data, permitting evaluation of smoking relapse rates, and all-cause, CVD and CHD mortality outcomes by nutrient intake and duration of diet exposure. Data recovery also permitted the first complete meta-analysis of LA intervention trials on mortality outcomes.

Objectives are (1) to evaluate whether increasing dietary linoleic acid alters CVD and CHD mortality, and (2) to assess whether changes in smoking relapse rates contribute to observed mortality differences.

Enrollment: 458 patients

Sex: Male

Ages: 30 to 59 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria:

• Clinical diagnosis of myocardial infarction, angina, or coronary insufficiency
• Willingness to attend Coronary Clinic in Sydney Australia on a regular basis

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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458 participants in 2 patient groups

Safflower oil

Experimental group

Treatment:

Other: Safflower oil

Control group (no diet instruction)

No Intervention group