Positive Health Online

Abstract

GUALLER and co-workers, Department of Epidemiology and Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD 21205-2223, USA, egualler@jhsph.edu, studied mercury, fish oils, and the risk of myocardial infarction.

Background

It has been suggested that mercury increases the risk of cardiovascular disease. Because fish intake is a major source of mercury exposure, the mercury contamination of fish might counteract the beneficial effects of fish n-3 fatty acids.

Methodology

In a case-control study conducted in 8 European countries and Israel, the joint association of mercury levels in toenail clippings and docosahexaenoic acid (DHA) levels in adipose tissue with the risk of first myocardial infarction in men was evaluated. The patients were 684 men with a first diagnosis of myocardial infarction, and the controls were 724 men selected to be representative of the same populations.

Results

After adjustment for DHA level and coronary risk factors, the mercury levels in patients were 15% higher than in control subjects. The odds ratio for myocardial infarction, after adjustment for risk factors, was 2.16 in the highest quintile of mercury compared to the lowest quintile. After adjustment for mercury, the DHA levels were found to be inversely associated with the risk of myocardial infarction.

Conclusion

Toenail mercury levels were directly associated with the risk of myocardial infarction, and the adipose-tissues DHA levels were inversely associated with the same risk. High mercury content may diminish the cardio-protective effect of fish intake.

References

Gualler E, Sanz-Gallardo MI, van-t-Veer P, Bode P, Aro A, Gomez-Aracena J, Kerk JD, Riemersma RA, Martin-Moreno JM, Kok FJ. Mercury, fish oils, and the risk of myocardial infarction. The New England Journal of Medicine 347 (22): 1747-1754, Nov 2002.