Taking fish oil or vitamin D? Large studies give long-awaited answers on who and when the benefits of these popular nutrients.
Fish oil taken by healthy people at a dose found in many supplements did not show a clear risk of reducing the risk of heart or cancer. The same applies to vitamin D.
But higher amounts of recycled fish oil have reduced cardiac and cardiac deaths in people with high triglycerides, a type of blood fat, and other risks of heart disease. Doctors welcomed the results and said that they could propose new treatment for hundreds of thousands of patients, such as you.
Up to 10 percent of adults in the United States take fish oil. More to take vitamin D, despite major studies that would support many of the health claims that were made to it.
"Those who give birth promote it as good for everyone", but in this final test, vitamin D "showed a lot of nothing," said Dr. James Stein, a heart specialist at the University of Wisconsin-Madison. He did not play any role in studies or links with the companies involved.
The results were disclosed on Saturday at the American Heart Association Conference in Chicago and published by the New England Journal of Medicine.
About fish oil
These oils, also called omega-3 fatty acids, are found in salmon, tuna and some other fish. They reduce triglycerides and inflammation and have other effects. There are different types, including EPA and DHA.
One study tested 4 grams a day Amarin Corp. Vascep, concentrated EPA, in more than 8,000 patients with high triglycerides and a higher risk of heart problems for various reasons. Everyone has already taken statins, such as Lipitor or Zocor, to lower cholesterol. Half was compared with Vascepo and other capsules of mineral oil.
After five years, about 17% of those on the vascep experienced one of these problems – heart attack, stroke, cardiac deaths or clogged arteries requiring medical care compared to 22% of others.
This reduced the risk by 25 percent. Individual views, heartbeats, cardiac deaths and stroke were all together with Vascepo lower. Only 21 people should take Vascepo for five years to avoid one of the main problems they have been studying – favorable quotas, said Stein.
Side effects can be troubling: more people in vasceps were hospitalized due to an incorrect heart rate – 3% vs. 2% of the benchmark. Doctors say this is a confusion because other studies suggest that fish oil reduces this risk.
Concerns about problems with heart rhythm is that it can increase the risk of stroke, but it was among those on vasceps, said the head of the study dr. Deepak Bhatt from Brigham and Boston Women's Hospital.
Vascepa costs about $ 280 per month; many insurance companies cover this. Amarin sponsored the study and some study managers are working or consulting with the company.
The second study tested less than 1 gram of a daily dose of a different type of fish oil – EPA / DHA combo, sold as Lovaza or Omacor, and in generic form – for 26,000 people without previous heart or cancer problems.
After approximately five years, the combined measurements of heart attacks, strokes and other problems were similar for fish oil users and the comparative group. The rates of cancer and death were similar.
In the fish oil group there were fewer heart attacks – compared with 200 compared with 200. The study leader, dr. JoAnn Manson at Brigham and Women called this a "considerable benefit", but several independent experts agreed on the way in which the study was to follow, and some other results.
"These findings are speculative and should be confirmed in a separate test," said Dr. Steven Nissen from Cleveland Clinic.
Both studies have a problem: oils used for comparator groups that may not have been a true placebo. The Vascepa study used mineral oil that inhibited statin treatment, increased cholesterol and possibly worsened the comparative group and made Vascea look better than it was true.
In the second study, olive oil was used which could help make this comparative group better, but may have concealed any benefits for others from fish oil.
The leaders of both studies show that what effect from comparative oils is not enough to change the main results, and agreed by independent experts. But Nissen, who runs another oil oil survey, uses a comparison of corn oil.
Manson's studies also tested vitamin D, which makes the skin from exposure to the sun. It's hard to get enough food, such as milk, eggs and oily fish, although there are many foods that are enriched today. Some studies have found that people with a lower D content are more likely to develop cancer, but it is not known whether the supplements change this risk.
The study participants enjoyed 2,000 international D-3 units (the most active form of vitamin D, also called holecalciferol) or fake vitamin tablets, for five years.
Vitamin D did not affect the possibility of a heart attack or stroke or cancer development. After eliminating the first two years of use, researchers among those on vitamin-112 compared to 149 in the placebo group saw less cancer deaths.
"Cancer can take years to develop," so there may not be a difference, Manson said. "It looks promising," and people will be studying longer to determine if the trend follows.
Several other experts said that these numbers only indicate a potential benefit that needs more study.
"These" positive "results must be interpreted with caution," Dr. Clifford Rosen of the Maine Medical Center and dr. John Keaney Jr. University of Massachusetts in a commentary in a medical journal.