Could High-Dose Fish Oil Raise Odds for Atrial Fibrillation in Heart Patients?

Amy Norton wrote . . . . . . . . .

Many people take fish oil to protect their heart, but a new study suggests that prescription versions may raise the risk of a common heart rhythm disorder.

At issue are prescription-strength omega-3 fatty acids, which are naturally found in fish oil. The medications are often prescribed to people with very high triglycerides, a type of blood fat linked to increased risk of heart attack and stroke.

According to the American Heart Association, prescription omega-3s can lower triglycerides by 20% to 30% in most people.

But the medications are also controversial, because their ultimate benefits for the heart are unclear.

Now the new study — an analysis of five past clinical trials — suggests caution is in order. Overall, trial patients given omega-3s were over one-third more likely to develop atrial fibrillation (a-fib) than those given a placebo. The fish oil doses taken ranged from 0.84 grams to 4 grams per day.

A-fib is a common heart rhythm disorder, or arrhythmia, in which the heart’s upper chambers begin to quiver chaotically instead of contracting effectively.

A-fib is not immediately life-threatening, but it’s “not benign,” either, said Dave Dixon, one of the researchers on the study and an associate professor at Virginia Commonwealth University (VCU), in Richmond.

Over time, Dixon said, a-fib can lead to complications like heart failure or stroke.

Exactly how prescription-strength omega-3 could contribute to a-fib is unclear, according to Dixon.

However, the increased risk was fairly consistent across the trials — more consistent, in fact, than heart benefits were, said co-researcher Salvatore Carbone, an assistant professor at VCU.

In all five trials, there were more a-fib cases among omega-3 patients than placebo patients, though the difference in risk was not statistically significant in all studies.

But when the researchers pooled the results of all five trials, there was a clear result: Omega-3 patients were 37% more likely to develop a-fib than placebo patients were.

In contrast, only one trial showed that an omega-3 product could cut the risks of other heart conditions.

In that trial, dubbed REDUCE-IT, patients using a product called Vascepa (icosapent ethyl) saw their risk of “cardiovascular events” drop by 25%. That included heart attack, stroke and death from cardiovascular causes.

Even in that study, though, a-fib risk rose among omega-3 users, by 35%.

Why has only one trial found heart benefits? Again, it’s not yet clear, Dixon said.

But, he added, Vascepa is different from the fish oil products tested in the other trials. It contains only one omega-3, called EPA, while the other products contain a combination of EPA and DHA.

And in the REDUCE-IT trial, Dixon said, higher levels of EPA in patients’ blood correlated to lower cardiovascular risks.

That hints, he said, that focusing on EPA might be “the way to go in the future.” But the conflicting findings on the benefits of omega-3s — along with the potential risk of a-fib — highlight the need for more studies, the researchers said.

The analysis was published in the European Heart Journal — Cardiovascular Pharmacotherapy.

Findings on the heart benefits of fish oil have indeed been “inconsistent,” said Linda Van Horn, a member of the heart association’s nutrition committee and a professor at Northwestern University Feinberg School of Medicine, in Chicago.

And that includes low-dose, over-the-counter fish oil supplements.

“There are limited and inconsistent data regarding the benefit or risk of taking fish oil supplements,” Van Horn said.

So the heart association recommends eating two servings of fish a week instead. Van Horn said that fatty fish, such as salmon, trout, albacore tuna and herring, are the best sources of omega-3s.

The trials in the current analysis tested prescription-strength omega-3s. But Carbone said he would be cautious about over-the-counter fish oil supplements, too.

“We don’t know if over-the-counter products could have these same effects,” he said.

Over-the-counter fish oil is considered a dietary supplement, so it is not regulated by the U.S. Food and Drug Administration as a drug would be, Dixon pointed out.

Both he and Carbone said it’s best to talk to a doctor or pharmacist before starting any fish oil product — and that people on prescription omega-3s should speak with their doctor before stopping.

Source: HealthDay

Study: Fish Oil, Vitamin D Won’t Prevent Atrial Fibrillation

For people hoping to prevent the heart rhythm disorder known as “a-fib,” new research shows that taking vitamin D or fish oil supplements won’t help.

A-fib, also known as atrial fibrillation, affects more than 33 million people worldwide and is the most common type of abnormal heart rhythm. It can cause symptoms that affect a person’s quality of life, result in blood clots that can cause a stroke, and also lead to heart failure.

For the study, the researchers examined whether taking vitamin D supplements or omega-3 fatty acids found in fish oil might affect different kinds of a-fib, and whether some patients would be more likely to benefit or be harmed by the supplements.

Overall, the results were mostly consistent across the different types of a-fib and patient groups, according to lead author Dr. Christine Albert and colleagues. Albert is chair of the cardiology department at Smidt Heart Institute in Los Angeles.

The study, published March 16 in the Journal of the American Medical Association, follows a presentation by Albert at an American Heart Association conference last year.

“Our recommendation remains the same,” she said in a JAMA Network news release. “We do not support taking fish oil or vitamin D supplements to prevent atrial fibrillation.”

However, “unlike other recent trials that found increased risks of atrial fibrillation with higher-dose omega-3 fatty acid supplements, our study did not find a significantly increased risk of atrial fibrillation with one gram of fish oil per day, which is good news for individuals taking low-dose fish oil for other health conditions,” Albert said.

Her team also found that vitamin D supplements at 2,000 international units per day did not increase a-fib risk.

Source: HealthDay

Study: High-Dose Vitamin D Won’t Prevent Seniors’ Falls

High doses of vitamin D may increase seniors’ risk of falls, rather than reduce it, according to a new study.

Preliminary studies suggested vitamin D may increase muscle strength and improve balance, so Johns Hopkins researchers investigated whether high doses of vitamin D might reduce the risk of falls in people aged 70 and older.

But the investigators found that large doses of vitamin D supplements were no better at preventing falls in this age group than a low dose.

“There’s no benefit of higher doses but several signals of potential harm,” study author Dr. Lawrence Appel said in a Hopkins news release.

“A lot of people think if a little bit is helpful, a lot will be better. But for some vitamins, high-dose supplements pose more risks than benefits. There’s a real possibility that higher doses of vitamin D increase the risk and severity of falls,” said Appel, a professor of medicine with joint appointments in epidemiology, international health and nursing.

Taking 1,000 or more international units per day (IU/day), equivalent to 25 micrograms/day of vitamin D, was no better than 200 IU/day at preventing falls, according to the study, which was funded by the U.S. National Institute on Aging.

The results were published Dec. 8 in the journal Annals of Internal Medicine.

The researchers also found that vitamin D supplement doses of 2,000 and 4,000 IU/day seemed to increase the risk and severity of falls compared with 1,000 IU/day, a relatively common dose for a pure vitamin D supplement.

Another finding was that serious falls and falls that required hospitalization occurred more often in older people who took 1,000 or more IU/day than in those who took 200 IU/day (about half the typical dose found in multivitamins).

Older folks should talk with their doctors about their fall risk and vitamin D levels in order to determine whether or not to continue taking vitamin D supplements, Appel recommended.

Source: HealthDay

Fish Oil and Vitamin D Supplements Not Effective for Preventing Atrial Fibrillation

Taking omega-3 fatty acids and vitamin D3 supplements does not neither increase nor decrease the risk of developing atrial fibrillation, according to late-breaking research presented today at the American Heart Association’s Scientific Sessions 2020. The virtual meeting is Friday, November 13 – Tuesday, November 17, 2020, and is a premier global exchange of the latest scientific advancements, research and evidence-based clinical practice updates in cardiovascular science for health care worldwide.

Atrial fibrillation is a rapid, irregular heartbeat caused by chaotic electrical signals in the top chambers of the heart. Atrial fibrillation is the most common heart rhythm disturbance, and it can lead to blood clots, strokes, heart failure and other heart-related complications. Atrial fibrillation risk increases with age, high blood pressure and heavy drinking and can be common among multiple, biologically related family members.

Evidence from previous observational studies has been conflicting, suggesting both risks and potential health benefits of fish oil – a source of omega-3 fatty acids – and vitamin D for atrial fibrillation.

“Once established, atrial fibrillation is difficult to treat and results in symptoms that can impair patients’ quality of life,” said Christine M. Albert, M.D., M.P.H., founding chair of the department of cardiology in the Smidt Heart Institute at Cedars-Sinai Medical Center in Los Angeles and lead author of this study. “Current treatment options have limited long-term success and significant risks, and there is a pressing need for preventive strategies.”

The VITAL Rhythm Trial is the first, placebo-controlled, randomized clinical trial investigating preventive therapies for atrial fibrillation. This trial evaluated whether supplementation with vitamin D3 (2000 IU/day) and omega-3 fatty acids (EPA:DHA in 1.2:1 ratio; 840mg/day) can reduce the risk of developing atrial fibrillation compared to placebo.

The five-year study, from 2012 – 2017, included 25,119 adults, ages 50 and older who had no history of atrial fibrillation. About half of the participants were female, 21% were black, and the average age was 67. Atrial fibrillation diagnoses were established both by participant self-report and claims data from the Centers for Medicare and Medicaid Services. Electrocardiogram evidence and/or a physician’s report documenting a new diagnosis of atrial fibrillation were required for confirmation.

During the trial follow-up period, 900 participants developed atrial fibrillation, 3.6% of the study population. There were no statistically significant differences between the groups who were assigned to supplemental EPA/DHA and/or vitamin D3 compared to individuals who were assigned to the placebo.

Albert added, “With regards to clinical care, these results do not support using marine omega-3 fatty acids or vitamin D to prevent atrial fibrillation. However, the results do provide reassurance that these supplements do not increase the overall risk of atrial fibrillation and appear to be generally safe for patients who are taking these supplements for other reasons.”

Source: American Heart Association

Compared to Placebo, Vitamin D Has No Benefit for Asthma

Contrary to earlier results, vitamin D supplements do not prevent severe asthma attacks in at-risk children, according to the first placebo-controlled clinical trial to test this relationship.

These results were published today in JAMA.

Juan Celedon release “The reason that’s important is there are colleagues around this country and worldwide who are testing vitamin D levels for kids with asthma and giving them vitamin D,” said study lead author Juan C. Celedón, M.D., Dr.P.H., chief of pediatric pulmonary medicine at UPMC Children’s Hospital of Pittsburgh. “As a system, it costs a lot of money to run all these tests and give the supplements. We’ve shown no benefit for children with moderately low vitamin D levels.”

For three years, the Vitamin-D-Kids Asthma (VDKA) Study followed nearly 200 children ages 6 to 16 across seven different U.S. hospital systems. All had at least one asthma attack during the year before the study began.

Half of the participants were randomized to receive 4,000 IU of vitamin D per day, and the other half got placebo pills. No one involved in the study knew which type of pill each participant was getting.

All of the children had vitamin D levels low enough that supplements should have an effect — if vitamin D truly is beneficial for reducing severe asthma attacks — but the study excluded children with severe vitamin D deficiency because it would be unethical to withhold it in those cases.

Compared to placebo, vitamin D did not reduce the number of asthma attacks participants experienced or their reliance on inhaled steroids.

That’s different from what was seen in the past with observational studies in Costa Rica, the U.S. and Canada, and Puerto Rico, where children with naturally low vitamin D levels seemed to have worse asthma.

“With observational studies, you never know — is vitamin D causing asthma to be worse or do kids with worse asthma end up having lower vitamin D?” said Celedón, who also holds the Niels K. Jerne chair of Pediatrics at the University of Pittsburgh School of Medicine.

Even with the rigor of the present study’s design, Celedón acknowledges that he can’t draw conclusions about whether very low vitamin D levels contribute to asthma attacks, but he argues that those children would be supplemented either way because of known effects on bone health.

Source: UPMC