Taking fish oil or vitamin D? Large studies give long-awaited answers to who does and does not enjoy these popular nutrients.
Fish oil taken by healthy people, in a dose found in many supplements, showed no clear ability to reduce the risk of heart cancer or cancer. The same is true for vitamin D.
But higher amounts of purified oil, prescription fish oil have reduced heart problems and heart-related deaths among people with high triglyceride levels, a type of fat in the blood, and other risks to heart disease. The doctors applauded the results and said they could offer a new treatment for hundreds of thousands of such patients.
Up to 10 percent of adults in the US take fish oil.I even take more vitamin D, although large studies support many health claims made about it.
"Those who sell it promote it for the best of everything," said Dr. James Stein, a heart specialist at the University of Wisconsin at Madison, who had no role in studies or corporate relationships. .
The results were discovered Saturday at the American Heart Association conference in Chicago and published by the New England Journal of Medicine.
On fish oil
These oils, also called omega-3 fatty acids, are found in salmon, tuna and other fish. They reduce triglyceride levels and inflammation and may have other effects. There are different types, including EPA and DHA.
One study examined 4 grams a day of Amarin Corp.'s prescription, which is EPA concentrated, in more than 8,000 patients with high triglyceride levels and a higher risk of heart problems for various reasons. Everyone is already taking a statin like Lipitor or Zucor to lower cholesterol. Half were given to the glare and the rest, mineral oil capsules in comparison.
Five years later, about 17 percent of those who had had the disorder had heart attack, stroke, heart-related death or clogged arteries that required medical treatment, compared to 22 percent of others.
This worked on a 25 percent reduction in risk. Personally, heart attacks, heart-related death and stroke were all lower with Vasapet. Only 21 people had to take Vassepa for five years to avoid one of the main problems studied – favorable prospects, Stein said.
Side effects may be feared: More people on VASCEPA were hospitalized for irregular heart beats – 3 percent versus 2 percent of the comparison group. Doctors say it is puzzling that other studies suggest fish oil reduces the risk.
The concern about the heart rate problem is that it can increase the risk of stroke, but there was less stroke among those in Asapa, Dr. Deepak Bhatt of Brigham and Women's Hospital in Boston said.
Vasca costs about $ 280 per month; Many insurers cover it. Amarin sponsored research and some research leaders to work or consult for the company.
The second study examined a lower daily dose of a different type of fish oil – an EPA / DHA combination sold like Lovaza or Omacor and generally in 26,000 people without previous heart problems or cancer.
After about five years, combined rates of heart attacks, strokes, and other problems were similar for fish oil users and the comparison group. Cancer and death rates were also similar.
There were fewer heart attacks in the fish oil group – 145 versus 200 in the comparison group. Research director Dr. Van Manson, at Brigham and Women's, called that a "significant advantage", but some independent experts disagreed because of the way the research was set up to track this and certain other outcomes.
"These findings are speculative and will need to be confirmed in a separate experiment," said Dr. Steven Nissan, Cleveland Clinic.
Both studies share a problem: the oils used in comparison groups, which may not have been real patients. The Vacepa study used mineral oil, which interferes with statin drugs, raises cholesterol, and may cause the comparison group to compare the situation and make Vacepa look better than it really was.
The second study used olive oil, which might have helped the comparison group do better, and perhaps mask all the benefits of other fish oil.
Leaders of the two studies say any effect from the comparison oils is not enough to change the main results, independent experts agreed. But Nissan, which leads another study of fish oil, uses corn oil for comparison.
Manson's study also examined vitamin D, which the skin makes from sun exposure. It is difficult to get enough foods like milk, eggs and fatty fish, although many foods are now fortified with it. Some studies have found that people with low levels of D are more likely to develop cancer, but it is not known if supplements alter the risk.
The study participants took 2,000 international units of D-3 (the most active form of vitamin D, also known as cholecalciferol) or fake vitamin pills for five years.
Vitamin D did not affect the chances of a heart attack or stroke or develop cancer. After no use during the first two years of use, the researchers found fewer cancers among those found in vitamin-112 vs 149 in the placebo group.
"Cancer can take years to develop," so the difference may not appear immediately, Manson said, "it looks promising" and people will be further investigated to see if the trend is rising, she said.
Other experts have said that these numbers are just a hint of a potential advantage that should learn more.
"These positive results must be interpreted cautiously," wrote Dr. Clifford Rosen of the Maine Center and Dr. John Kinney, MD, of the University of Massachusetts in an article published in the medical journal.