U-shaped curve revealed for association between fish consumption and atrial fibrillation

June 24, 2013, European Society of Cardiology

Moderation seems to be key when it comes to eating fish to prevent atrial fibrillation (AF) according to an observational study presented at the EHRA EUROPACE congress held 23 to 26 June in Athens, Greece.

The study found a U-shaped association between consumption of marine n-3 (n-3 PUFA) and the risk of developing AF, with people who have both low and high intakes found to suffer more from AF than those with median intakes. The lowest risk of AF was found in those who consumed around 0.63 g marine n-3 PUFA per day, which corresponds to around two servings of fatty (oily) fish per week.

Earlier studies have reported that regular consumption of fish can exert in preventing the development of AF. Notably, in the Cardiovascular Health study², which included 4,815 participants, a 28% lower risk of AF was observed among people who consumed fish one to four times per week compared with those who ate fish less than once per month. However, such observed associations have not been confirmed in all cohort studies³?8.

In the current study, Doctor Thomas Rix and colleagues from Aalborg University Hospital in Denmark, set out to examine the that a negative association exists between the development of AF and consumption of n-3 PUFA. "Since AF is present in over six million people in Europe and associated with considerable morbidity, mortality and , preventing AF by achievable would be of major public interest," said Dr. Rix.

The investigators made use of the Danish Diet, Cancer and Health cohort 9, which between 1993 and 1997 enrolled a total of 57,053 Danish participants aged 50 to 64 years. The study, funded by the Danish Cancer society, had been initiated with the primary objective of exploring the role of diet in the development of cancer. recorded for the study included a semi quantitative food frequency questionnaire with detailed questions about the consumption of fish and food products containing fish that enabled the calculation of average n-3 PUFA intakes. Levels of N-3 PUFA/day were divided into quintiles: with quintile 1 representing 0.00-0.38g marine n-3 PUFA/ day; quintile 2 representing 0.39-0.53g marine n-3 PUFA/day; quintile 3 representing 0.54 to 0.73 g marine n-3 PUFA/day; quintile 4 0.74 to 0.99 g marine n-3 PUFA/day; and quintile 5 1.00-7.22 g marine n-3 PUFA/day.

Follow-up of AF events in the population was undertaken using the Danish National Patient Registry, which recorded discharge diagnoses from hospital admissions, emergency rooms and outpatient clinics. The registry was facilitated by the Danish practice of identifying every citizen with a unique personal identification number that enables cross links to be made between different national registries.

Altogether a total of 3,425 incident cases of AF were registered during 13.6 years of follow-up. When data was analysed in a multivariate Cox regression model, in comparison to the lowest quintile a 9% lower risk of AF was seen for the second quintile (HR 0.91 95% CI 0.81-1.02); a 13 % lower risk of AF was seen for the third quintile (HR 0.87, 95% CI 0.78-0.98, p=0.02); a 4% lower rate was seen for the fourth quintile (HR 0.96, 95% CI 0.86-1.07) and a 3% increased rate was seen for the 5th quintile (HR 1.03, 95% CI 0.92-1.15).

"The 13% observed lower risk of AF seen at moderate intakes of marine n-3 PUFA compared with low intakes may be related to a reduction in ischemic heart disease and anti-inflammatory effects in addition to direct anti arrhythmic effects," said Dr. Rix. He noted that in one study, treatment with 1.8g n-3PUFA/day in patients with low intakes of fish resulted in prolongation of the atrial effective refractory period and less inducible AF, both in subjects with AF8 and subjects without AF10.

The biological mechanisms behind the higher risk of AF observed for high intakes of n-3 PUFA compared to moderate intakes were more difficult to explain," said Dr. Rix. "We can only speculate that the balance between AF inhibiting and AF promoting effects can change according to co morbidities and intakes of marine n-3PUFA. This is the first time that such an association has been shown and it needs to be explored in further studies. However, it may help explain some of the contradictory results obtained in earlier studies."

Explore further: Fatty acids don't reduce atrial fibrillation recurrence

Related Stories

Fatty acids don't reduce atrial fibrillation recurrence

December 21, 2012
(HealthDay)—Polyunsaturated fatty acids (n-3 PUFA) do not reduce the recurrence of atrial fibrillation (AF), according to a study published online Dec. 19 in the Journal of the American College of Cardiology.

Depression screening in AF Clinics recommended by study

June 23, 2013
Electrophysiologists (EPs) rate the quality of life of patients with Paroxysmal atrial fibrillation (AF) significantly better than the patients themselves do, with the greatest level of disagreement about mental health. The ...

Palpitations are predictive of future atrial fibrillation: large population study

May 15, 2012
A large cohort study has found that the strongest risk factors for atrial fibrillation in both men and women were a history of palpitations and hypertension. While hypertension is a well known risk factor for AF, the investigators ...

Is moderate alcohol intake associated with risk of atrial fibrillation among patients with CVD?

October 12, 2012
An analysis of the association of alcohol consumption with the development of atrial fibrillation (AF) among subjects with coronary heart disease, stroke, diabetes, or other manifestations of cardiovascular disease (CVD) ...

n-3 PUFA may reduce markers of kidney disease in T2DM

February 8, 2013
(HealthDay)—In patients with type 2 diabetes and evidence of kidney injury, supplementation with n-3 long-chain polyunsaturated fatty acids (PUFA) does not reduce urine albumin excretion but is associated with a reduction ...

Recommended for you

A nanoparticle inhalant for treating heart disease

January 18, 2018
A team of researchers from Italy and Germany has developed a nanoparticle inhalant for treating people suffering from heart disease. In their paper published in the journal Science Translational Medicine, the group describes ...

Starting periods before age of 12 linked to heightened risk of heart disease and stroke

January 15, 2018
Starting periods early—before the age of 12—is linked to a heightened risk of heart disease and stroke in later life, suggests an analysis of data from the UK Biobank study, published online in the journal Heart.

'Decorated' stem cells could offer targeted heart repair

January 10, 2018
Although cardiac stem cell therapy is a promising treatment for heart attack patients, directing the cells to the site of an injury - and getting them to stay there - remains challenging. In a new pilot study using an animal ...

Two simple tests could help to pinpoint cause of stroke

January 10, 2018
Detecting the cause of the deadliest form of stroke could be improved by a simple blood test added alongside a routine brain scan, research suggests.

Exercise is good for the heart, high blood pressure is bad—researchers find out why

January 10, 2018
When the heart is put under stress during exercise, it is considered healthy. Yet stress due to high blood pressure is bad for the heart. Why? And is this always the case? Researchers of the German Centre for Cardiovascular ...

Heart-muscle patches made with human cells improve heart attack recovery

January 10, 2018
Large, human cardiac-muscle patches created in the lab have been tested, for the first time, on large animals in a heart attack model. This clinically relevant approach showed that the patches significantly improved recovery ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Jim4321
1 / 5 (2) Jun 24, 2013
This is an interesting speculation. The authors needed to note that their associations were not significant -- as written up in the press release. Presumably, the shape of the curve could only be determined by ignoring the confidence intervals for each quintile. For example, the confidence intervals for the third ("lowest") quintile and the fifth ("highest") quintile overlap.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.