NFI - SISA

Long-term fish consumption is associated with protection against arrhythmia in healthy persons in a Mediterranean region--the ATTICA study

Chrysohoou C et al.
Am J Clin Nutr. 2007 May;85(5):1385-91

Una dieta ricca di acidi grassi omega 3 avrebbe effetti benefici sul ritmo cardiaco e proteggerebbe contro il rischio di morte improvvisa. È questa la conclusione di uno studio pubblicato sull’American Journal of Clinical Nutrition che ha coinvolto più di 3 mila persone (uomini e donne di età media 45 anni) per ricercare l’associazione tra il consumo di pesce e omega-3 e il rischio di aritmie cardiache. I partecipanti hanno compilato un questionario per stabilire le abitudini alimentari, il livello di attività fisica e il consumo di alcool; inoltre, sono stati sottoposti a elettrocardiogramma per la misurazione di alcuni parametri cardiaci.
Gli autori hanno osservato che coloro che consumavano più di 300 grammi a settimana presentavano una riduzione del 13,6% dell’intervallo QT, rispetto a chi non ne mangiava; la riduzione passava al 29,2% dopo aggiustamento dei dati per età, sesso, livello di attività fisica, indice di massa corporea, abitudine al fumo e consumo di noci. L’intervallo QT è un indicatore delle caratteristiche del ciclo elettrico del cardiaco; elevati intervalli QT, in particolare indicano una lenta ripolarizzazione ventricolare e sono stati associati a un aumento del rischio di morte improvvisa.

BACKGROUND: Dietary habits have long been associated with many manifestations of cardiovascular disease. OBJECTIVE: We sought to investigate whether a diet enriched with fish and n-3 fatty acid consumption are associated with changes in the potential duration of the electrical action, as represented by the QT duration on a resting electrocardiogram, in a population-based sample of Greek adults. DESIGN: During 2001 and 2002, we randomly enrolled 1514 men (18-87 y old) and 1528 women (18-89 y old) stratified by age and sex distribution (in the 2001 Greek census) from the Attica area, Greece. We studied several demographic, anthropometric, lifestyle, dietary, and bioclinical factors of the participants. Dietary habits (including fish consumption) were evaluated by using a validated food-frequency questionnaire. All subjects underwent electrocardiography with a 12-lead surface, in which, along with several other indexes, QT duration was measured, and the heart rate-corrected QT (QTc) was calculated (corrected by using Bazett's rate). The tested hypothesis was evaluated through multiple linear regression analysis, after control for physical activity status, sex, age, medication intake, and several other potential confounders. RESULTS: Compared with fish nonconsumers, those who consumed >300 g fish/wk had a mean 13.6% lower QTc (P<0.01). These findings were confirmed after adjustment for age, sex, physical activity status, BMI, smoking habits, intake of nuts, and other confounders. Moreover, compared with fish nonconsumers, those who consumed >or=300 g fish/wk had a 29.2% lower likelihood of having QTc intervals >0.45 s (P=0.03). CONCLUSIONS: Long-term consumption of fish is associated with lower QTc interval in free-eating people without any evidence of cardiovascular disease. Thus, fish intake seems to provide antiarrhythmic protection at a population level.