Taking vitamin D and omega-3 fatty acid supplements may help reduce the risk of cancer and heart attacks, a recent study finds. Researchers found that omega-3 fish oil reduced heart attack rates but did not affect stroke or cancer rates, while vitamin D was linked with a decrease in cancer deaths starting one to two years after participants began treatment.
Researchers studied the effects of the supplements on 25,871 men and women age 50 and older from across the U.S. for 5.3 years. They divided the participants into four groups based on the supplements given: those given vitamin D and omega-3s, those given just vitamin D, those given just omega-3s, and those given placebos.
What they found is a 28 percent reduction in heart attack risk among participants who took omega-3 supplements, but no effect on cancer. The reduction of heart attack risk among those taking omega-3s was significant among African-Americans, with a 77 percent reduction found. Researchers also discovered cancer deaths were reduced by 25 percent among those taking vitamin D, with no effect on heart attack risk.
Earlier trials researched whether fish oil or other supplements prevent heart attacks or strokes in patients with either a history of heart disease or at very high risk for it. The study is the first large trial of omega-3 supplements to prevent the occurrence of heart disease in a general population. The study, conducted by researchers from Brigham and Women's Hospital, is the first randomized clinical trial of vitamin D and omega-3s on a racially diverse population. Twenty percent of the participants were African American.
Researchers are looking at the effects of vitamin D and omega-3s on rates of diabetes, cognitive function, autoimmune disease, respiratory infections, depression, and more.
"Over the next six months, we will have even more results to share that may help clinicians and patients understand the benefits and risks of taking omega-3 and vitamin D supplements," said lead author JoAnn Manson, MD, DrPH, chief of the Division of Preventive Medicine at the Brigham.
Manson recommends that for people already taking the supplements, "there's no clear reason to stop." However, for those who "want to consider starting, our recommendation is to talk with your healthcare provider, but this does not need to be done on an urgent basis," she said.