Previous studies have indicated a protective effect of long-chain omega 3 polyunsaturated fatty acids against cardiovascular disease; however, women are underrepresented in cardiovascular research.
The aim of this study was to explore the association between intake of omega 3s and the risk of cardiovascular disease in a large prospective cohort of young women (mean age at baseline: 29.9 years [range: 15.7–46.9]). Exposure information on 48,627 women from the Danish National Birth Cohort was linked to the Danish National Patients Registry for information on events of hypertensive, cerebrovascular and ischemic heart disease used to define a combined measure of cardiovascular diseases.
Intake of fish and omega 3s was assessed by a food-frequency questionnaire and telephone interviews. During follow-up (1996–2008; median: 8 years), 577 events of cardiovascular disease were identified. Low omega 3 intake was associated with an increased risk of cardiovascular disease (adjusted hazard ratio for women in lowest versus highest omega 3 intake group: 1.91 [95% CI: 1.26–2.90]).
Restricting the sample to women who had consistently reported similar frequencies of fish intake across three different dietary assessment occasions tended to strengthen the relationship (hazard ratio for lowest versus highest intake: 2.91 [95% CI: 1.45–5.85]).
Furthermore, the observed associations were consistent in supplementary analyses where omega 3 intake was averaged across the three dietary assessment occasions, and the associations were persistent for all three of the individual outcomes. Findings based on a large prospective cohort of relatively young and initially healthy women indicated that little or no intake of fish and omega 3s was associated with an increased risk of cardiovascular disease.