MONDAY, Could 3, 2021 (HealthDay Information) — Many individuals take fish oil to guard their heart, however a brand new research means that prescription variations might increase the chance of a typical coronary heart rhythm dysfunction.
At problem are prescription-strength omega-3 fatty acids, that are naturally present in fish oil. The medicines are sometimes prescribed to individuals with very excessive triglycerides, a sort of blood fats linked to elevated danger of heart attack and stroke.
In accordance 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 center are unclear.
Now the brand new research — an evaluation of 5 previous clinical trials — suggests warning is so as. Total, trial sufferers given omega-3s had been over one-third extra more likely 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, by which the center’s higher chambers start to quiver chaotically as a substitute of contracting successfully.
A-fib will not be instantly life-threatening, nevertheless it’s “not benign,” both, mentioned Dave Dixon, one of many researchers on the research and an affiliate professor at Virginia Commonwealth College (VCU), in Richmond.
Over time, Dixon mentioned, 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 line with Dixon.
Nevertheless, the elevated danger was pretty constant throughout the trials — extra constant, in reality, than coronary heart advantages had been, mentioned 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 danger was not statistically vital 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 more likely 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 known as Vascepa (icosapent ethyl) noticed their danger of “cardiovascular occasions” drop by 25%. That included coronary heart assault, stroke and demise from cardiovascular causes.
Even in that research, although, a-fib danger rose amongst omega-3 customers, by 35%.
Why has just one trial discovered coronary heart advantages? Once more, it is not but clear, Dixon mentioned.
However, he added, Vascepa is totally different from the fish oil merchandise examined within the different trials. It accommodates just one omega-3, known as EPA, whereas the opposite merchandise comprise a mix of EPA and DHA.
And within the REDUCE-IT trial, Dixon mentioned, increased ranges of EPA in sufferers’ blood correlated to decrease cardiovascular dangers.
That hints, he mentioned, that specializing in EPA is likely to be “the way in which to go sooner or later.” However the conflicting findings on the advantages of omega-3s — together with the potential danger of a-fib — spotlight the necessity for extra research, the researchers mentioned.
The evaluation was printed April 29 within the European Coronary heart Journal — Cardiovascular Pharmacotherapy.
Findings on the center advantages of fish oil have certainly been “inconsistent,” mentioned Linda Van Horn, a member of the center affiliation’s diet 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 information relating to the profit or danger of taking fish oil dietary supplements,” Van Horn mentioned.
So the center affiliation recommends consuming two servings of fish per week as a substitute. Van Horn mentioned that fatty fish, similar to salmon, trout, albacore tuna and herring, are the most effective sources of omega-3s.
The trials within the present evaluation examined prescription-strength omega-3s. However Carbone mentioned he can be cautious about over-the-counter fish oil dietary supplements, too.
“We do not know if over-the-counter merchandise may have these identical results,” he mentioned.
Over-the-counter fish oil is taken into account a dietary complement, so it’s not regulated by the U.S. Meals and Drug Administration as a drug can be, Dixon identified.
Each he and Carbone mentioned 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 communicate 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 companies, division of pharmacotherapy and outcomes science, Virginia Commonwealth College, Richmond, Va.; Linda Van Horn, PhD, RD, professor and chief, diet division, division of preventive drugs, Northwestern College Feinberg College of Medication, Chicago, and member, Diet Committee, American Coronary heart Affiliation, Dallas; European Coronary heart Journal—Cardiovascular Pharmacotherapy, April 29, 2021, on-line