Alpha-Linolenic Acid Benefit In Artery Disease Questioned
Research findings question the belief that intake of dietary alpha-linolenic acid has a protective effect in preventing coronary artery disease (CAD).
Any effect is complicated by alpha-linolenic acid?s interaction with trans fatty acids.
“We observed no beneficial association between dietary alpha-linolenic acid intake and risk of 10-year CAD incidence in elderly Dutch men,” say researchers from the Netherlands.
“Substantial differences between crude and adjusted relative risks of CAD in association with alpha-linolenic acid intake in prospective studies, together with the limited evidence on the mechanisms, indicates that the protective cardiac effect of alpha-linolenic acid is questionable.”
They also point out that the investigation was complicated by the associations between intake of alpha-linolenic acid and trans fatty acids.
“We observed a non-significant, positive association between alpha-linolenic acid intake and CAD risk that seems to be the result of the strong association between intakes of alpha-linolenic acid and trans fatty acids.”
Investigators from the National Institute of Public Health and the Environment in Bilthoven and Wageningen University say the association between alpha-linolenic acid and trans fatty acids likely holds true in other populations.
“This emphasizes the importance of adjusting for other dietary factors and the difficulty in pursuing this hypothesis epidemiologically or to generalise the epidemiologic findings to other populations.”
Researchers prospectively studied 667 men from the Zutphen Elderly Study. Participants were aged from 64 to 84 years. All were free of CAD at baseline. Investigators used a crosscheck dietary history to assess dietary intake.
They note that the Zutphen Study was initiated in 1960 with a cohort of older men living in Zutphen. It was designed as the Dutch contribution to the Seven Countries Study. It was extended in 1985 to include a new cohort of older men in a study of diet and CAD called the Zutphen Elderly Study.
“During the 10-year follow-up, we documented 98 cases of CAD,” investigators report.
“After adjustment for age, standard coronary risk factors and intake of trans fatty acids and other nutrients, alpha-linolenic acid intake was not significantly associated with CAD risk.”
American Journal of Clinical Nutrition, 2001; 74: 457-463
