Background: Several animal experiments have documented that omega-3 fatty acid alpha-linolenic acid (ALA) (C 18:3, n-3) from vegetable oils has beneficial electrophysiological and antiarrhythmic effects. This may explain the protective effect of ALA against cardiovascular diseases and sudden death.
Materials and methods: We have continuously and systematically collected and evaluated relevant literature (observational and secondary prophylactic studies) and here present an overview of the effects of ALA on cardiovascular diseases and sudden death.
Results: Several observational studies in healthy individuals and in patients with coronary heart disease have indicated that a diet rich in ALA reduces coronary death and the risk for sudden death. A cross-sectional study has shown a beneficial effect of ALA on the progression of coronary atherosclerosis. Three secondary studies have also indicated beneficial effects of ALA on several cardiovascular end-points. Diet studies do have limitations, and the secondary prophylactic studies have not given a definite answer to whether ALA possesses beneficial cardiovascular effects.
Interpretation: On the whole, the observational and secondary prophylactic studies indicate that ALA may have cardioprotective effects in healthy individuals and in patients with coronary heart disease. For those who seldom eat fish and only take small amounts of fish oils, a diet rich on ALA may be an alternative.