According to the results of a new study, healthy people receive little benefit from fish oil or vitamin D when it comes to lowering heart or cancer risks. Researchers discussed the results of the studies at an American Heart Association conference in Chicago. The results have also been published in the New England Journal of Medicine.
Fish oils, also called omega-3 fatty acids, have been found to reduce triglycerides and inflammation, primary risks for heart disease. Fish oils are naturally found in salmon, tuna, and some other types of fish. Nearly 10 percent of US adults report taking fish oil supplements.
A study involving 26,000 people with no prior heart problems or cancer found that those taking a 1 gram daily dose of fish oil had similar rates of heart attacks, strokes, cancer, and deaths as a comparison group. While there were fewer heart attacks in the fish oil group, there is speculation that this was because of the way the study was set up.
People with high triglycerides did show some improvement when taking higher amounts of a purified, prescription fish oil. In a study involving more than 8,000 patients with high triglycerides and an increased risk of heart problems, researchers found that taking 4 grams a day of a prescription fish oil supplement lowered their risk of heart-related complications or death by 25 percent versus those taking mineral oil capsules.
Another study found that vitamin D supplements provided little benefit to healthy people. The skin naturally makes vitamin D from sun exposure, but it can be difficult to get enough from foods, leading to the popularity of the supplements. However, there are no major studies supporting the many health claims made regarding vitamin D supplements.
In the study, researchers found no statistical difference in the odds of having a heart attack or stroke or developing cancer between those taking a vitamin D supplement and those taking a fake vitamin pill. By taking out the first two years of use, researchers saw fewer cancer deaths among those taking the supplements. More research is needed to determine whether length of time taking the supplement results in lower risks for these conditions.