Consumption of fish with omega-3 lowered CVD risk in young women

Strøm M. Hypertension. 2012;59:36-43.

Issue: April 2012

Healthy, younger women who eat little or no fish and have a low intake of long-chain omega-3 polyunsaturated fatty acids appear to be at increased risk for CVD. However, these women may reduce their risk for developing CVD by eating more fish rich in omega-3 fatty acids, researchers reported in a new study.

Researchers assessed the diagnosis of cerebrovascular diseases, ischemic heart disease and hypertensive diseases in a group of 48,627 Danish women included in the Danish National Birth Cohort. All women were aged 15 to 49 years and completed two computer-assisted telephone interviews and a semiquantitative food frequency questionnaire that covered intake of fish and long-chain omega-3 polyunsaturated fatty acids (LCn3FA) in the previous month.

More than 500 CV events were identified during a median follow-up of 8 years. Fish and LCn3FA intake measured at one time point by the food frequency questionnaire showed that women with the lowest fish intake had an elevated CVD risk compared with women with the highest fish intake (adjusted HR=1.91; 95% CI, 1.26-2.90). Even women who ate fish only a couple of times per month benefited, the researchers said.

Further, among women who reported the same fish intake on three different measurement occasions during a 30-week period, those who never ate fish had a CVD risk approximately three times higher vs. women who ate fish every week (adjusted HR=2.89; 95% CI, 1.39-5.99).

“No increase in risk was observed for modest fish or LCn3FA intake,” the researchers wrote in the study.

Additional determinants of risk

Among the three endpoints studied, women with hypertensive diseases (HR=1.81; 95% CI, 1.03-3.19) had the lowest intake of LCn3FA, followed by those with cerebrovascular disease (HR=2.34; 95% CI, 1.10-4.99) and ischemic heart disease (HR=3.80; 95% CI, 1.53-9.42).

Low fish intake was also reported most among women who:

Were aged 25 years or younger.
Did not have children.
Smoked cigarettes.
Were overweight or obese.
Were less likely to attend high school.
Were less likely to be white-collar workers.
Were less likely to drink alcohol.
Were less likely to be physically active.

Cod, salmon, herring and mackerel were the most common fish consumed by women in the study.

Estimating risk

According to Marin Strøm, PhD, postdoctoral fellow at the Centre for Fetal Programming, Statens Serum Institut, Copenhagen, Denmark, “This is the first study of this size to focus exclusively on women of child-bearing age.

“The biggest challenge in getting health messages like this across to younger populations is that usually the benefits may not be evident for 30 or 40 years, but our study shows this is not the case. We saw a strong association with CVD in women who were still in their late 30s,” Strøm said in a press release.

These results are consistent with data from previous observational studies that suggested potential beneficial effects of moderate LCn3FA intake in older women, the researchers said.

Disclosure: The researchers report no relevant financial disclosures.

The omega-3 polyunsaturated fatty acids are consistently associated with less CAD as well as lower incidence of sudden cardiac death. While the mechanism for such benefit is unclear, there is ample evidence to indicate their benefit. This study is particularly interesting since it benefits young, premenopausal women, who we know are at low risk for CVD.

– Robert Roberts, MD, FRCPC, MACC
Cardiology Today Editorial Board member

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