A very popular supplement is often in the news: fish oil.
doctors often recommend it to their patients for a number of things: for your heart, digestion, your skin your hair, and your brain.
but fish oil is being talked about recently because of a new study: it narrows in on the effect it has... or doesn't have: on your heart.
nbc's chief science correspondent robert bazell has more:
Katie Kilan has been taking fish oil supplements as part of her heart healthy program for 20 years.
Katie: "Taking fish oils has lowered my cholesterol, and that makes me really happy, because I don't have to take any other medications."
She is hardly alone. The supplements are a source of Omega 3 fatty acid, which is know to be good for the heart. And while sales exceed a billion dollars a year, studies have repeatedly differed on just how much fish oil helps.
The research out today combined 20 previous studies involving more than 68,000 patients since 1989. The analysis, by Greek scientists was published today in the Journal of the American Medical Association,
Overall, the study concluded the supplements do neither neither harm nor good -- BUT it also showed that people taking fish oil supplements suffered nine per cent fewer heart deaths and 11 per cent fewer heart attacks. For several other factors ... sudden deaths, total deaths, and strokes ... the study found no significant difference.
Dr. Daryush Mozaffarian, Harvard School of Public Health: "If you focus on cardiac deaths -- the outcome most likely influenced by fish oil -- there is a significant benefit for that outcome."
Bridge One thing today's report finds is that older studies tended to show more benefit from the supplements than newer ones. Experts say that could be because people are taking better heart medications and eating more fish -- so the supplements don't matter as much.
Dr Mozaffarian: "I recommend to patients that they take fish as a first line measure and if they don't like fish or if they really want to be sure they are getting Omega 3's there's no harm to taking fish oil and it certainly might help."
Katie Kilan certainly follows that advice -- and nothing in the latest researcher will likely change her mind.