MONDAY, Might 3, 2021 (HealthDay Information) — Many individuals take fish oil to guard their heart, however a brand new examine means that prescription variations could increase the danger of a typical coronary heart rhythm dysfunction.
At concern are prescription-strength omega-3 fatty acids, that are naturally present in fish oil. The medicines are sometimes prescribed to folks with very excessive triglycerides, a sort of blood fats linked to elevated threat of heart attack and stroke.
In keeping with the American Coronary heart Affiliation, prescription omega-3s can decrease triglycerides by 20% to 30% in most individuals.
However the medicines are additionally controversial, as a result of their final advantages for the guts are unclear.
Now the brand new examine — an evaluation of 5 previous clinical trials — suggests warning is so as. Total, trial sufferers given omega-3s had been over one-third extra prone to develop atrial fibrillation (a-fib) than these given a placebo. The fish oil doses taken ranged from 0.84 grams to 4 grams per day.
A-fib is a typical coronary heart rhythm dysfunction, or arrhythmia, through which the guts’s higher chambers start to quiver chaotically as a substitute of contracting successfully.
A-fib shouldn’t be instantly life-threatening, however it’s “not benign,” both, stated Dave Dixon, one of many researchers on the examine and an affiliate professor at Virginia Commonwealth College (VCU), in Richmond.
Over time, Dixon stated, a-fib can result in problems like heart failure or stroke.
Precisely how prescription-strength omega-3 may contribute to a-fib is unclear, in response to Dixon.
Nevertheless, the elevated threat was pretty constant throughout the trials — extra constant, the truth is, than coronary heart advantages had been, stated co-researcher Salvatore Carbone, an assistant professor at VCU.
In all 5 trials, there have been extra a-fib instances amongst omega-3 sufferers than placebo sufferers, although the distinction in threat was not statistically important in all research.
However when the researchers pooled the outcomes of all 5 trials, there was a transparent consequence: Omega-3 sufferers had been 37% extra prone to develop a-fib than placebo sufferers had been.
In distinction, just one trial confirmed that an omega-3 product may lower the dangers of different coronary heart circumstances.
In that trial, dubbed REDUCE-IT, sufferers utilizing a product referred to as Vascepa (icosapent ethyl) noticed their threat of “cardiovascular occasions” drop by 25%. That included coronary heart assault, stroke and demise from cardiovascular causes.
Even in that examine, although, a-fib threat rose amongst omega-3 customers, by 35%.
Why has just one trial discovered coronary heart advantages? Once more, it isn’t but clear, Dixon stated.
However, he added, Vascepa is totally different from the fish oil merchandise examined within the different trials. It accommodates just one omega-3, referred to as EPA, whereas the opposite merchandise comprise a mixture of EPA and DHA.
And within the REDUCE-IT trial, Dixon stated, larger ranges of EPA in sufferers’ blood correlated to decrease cardiovascular dangers.
That hints, he stated, that specializing in EPA is perhaps “the way in which to go sooner or later.” However the conflicting findings on the advantages of omega-3s — together with the potential threat of a-fib — spotlight the necessity for extra research, the researchers stated.
The evaluation was printed April 29 within the European Coronary heart Journal — Cardiovascular Pharmacotherapy.
Findings on the guts advantages of fish oil have certainly been “inconsistent,” stated Linda Van Horn, a member of the guts affiliation’s vitamin committee and a professor at Northwestern College Feinberg College of Medication, in Chicago.
And that features low-dose, over-the-counter fish oil dietary supplements.
“There are restricted and inconsistent knowledge concerning the profit or threat of taking fish oil dietary supplements,” Van Horn stated.
So the guts affiliation recommends consuming two servings of fish every week as a substitute. Van Horn stated that fatty fish, akin to salmon, trout, albacore tuna and herring, are the very best sources of omega-3s.
The trials within the present evaluation examined prescription-strength omega-3s. However Carbone stated he could be cautious about over-the-counter fish oil dietary supplements, too.
“We do not know if over-the-counter merchandise may have these similar results,” he stated.
Over-the-counter fish oil is taken into account a dietary complement, so it isn’t regulated by the U.S. Meals and Drug Administration as a drug could be, Dixon identified.
Each he and Carbone stated it is best to speak to a physician or pharmacist earlier than beginning any fish oil product — and that individuals on prescription omega-3s ought to converse with their physician earlier than stopping.
Harvard Medical College has extra on fish oil and heart health.
SOURCES: Salvatore Carbone, PhD, assistant professor, kinesiology and well being sciences, Virginia Commonwealth College, Richmond, Va.; Dave L. Dixon, PharmD, affiliate professor, ambulatory care, and vice-chair, scientific providers, division of pharmacotherapy and outcomes science, Virginia Commonwealth College, Richmond, Va.; Linda Van Horn, PhD, RD, professor and chief, vitamin division, division of preventive medication, Northwestern College Feinberg College of Medication, Chicago, and member, Vitamin Committee, American Coronary heart Affiliation, Dallas; European Coronary heart Journal—Cardiovascular Pharmacotherapy, April 29, 2021, on-line