*sigh*
 

So tired of this crap, when you do something because you think it will benefit your health, then read something like this basically telling you you're wasting your time.

24/03/2006 - Intake of omega-3 fatty acids from oily fish and fish oil supplements has no effect on mortality, heart disease or cancer, concludes a new review, but guidelines should continue for consumption.

Omega-3 fatty acids have been linked to a wide-range of health benefits, including cardiovascular disease (CVD), good development of a baby during pregnancy, joint health, behaviour and mood, and certain cancers.

Most studies have suggested that oil fish and omega 3 supplements reduced mortality, but a large, long-term RCT by Michael Burr and colleagues from the University of Wales College of Medicine, Cardiff (European Journal of Clinical Nutrition, 2003, Vol. 57, pp. 193-200) reported men with angina taking fish oil capsules had a higher risk of heart attack.

The new meta-analysis, published on-line in the British Medical Journal (doi: bmj.38755.366331.2F), reviewed 48 randomised clinical trials (RCT) with 36913 participants and between six months and six years of follow-up, and 41 cohort studies with over half a million participants and follow-up of up to 25 years.

“Long chain and shorter chain omega 3 fats do not have a clear effect on total mortality, combined cardiovascular events, or cancer,” wrote lead author Lee Hooper from the University of East Anglia.

In terms of total mortality, the analysis showed that omega 3 fats reduced the risk by 13 per cent, but this was not deemed to be significant.

No significant decreases in risk for either cardiovascular events, including stroke, or cancer were reported.

These results differ from a recent review by Heiner Butcher from the Institute of Clinical Epidemiology, Basel, Switzerland (American Journal of Medicine, 2002, Vol. 112, pp. 298-304), which suggested important benefits of omega-3 fatty acids for morbidity and mortality in coronary heart disease.

However, if the East Anglia researchers omitted the RCT of Burr, similar statistically significant benefits of omega-3 acids were observed.

“It is not clear why the results of Burr et al differ from the other large studies on fish based omega 3,” said Hooper.

The Burr study had the longest follow up of all the RCTs analysed and was only focused at men with angina, both of which may cause the contradictory results, said Hooper and colleagues.

Hooper and colleagues stressed that the general public should still be encouraged to consume omega-3 from oily fish or supplements.

“This advice should continue at present but the evidence should be reviewed regularly.”

In an accompanying editorial, Eric Brunner from the Royal Free and University College London Medical School agreed: “For the general public some omega 3 fat is good for health. Long chain omega 3 fatty acids are structural components of neuronal and other cell membranes, and they modulate the production of eicosanoids and inflammatory cytokines.”

:rofl: I heard about that this morning! :doh: I think science is fine up to a point... But when you get to fine tune things, I think a lot of it is luck!

That's why I take everything I read or hear with a grain of salt. I'm so tired of hearing one thing and then a few months or years later, it being taken back.

I'd like to weigh in on this one. I teach research design courses and have recently started to emphasize scientific literacy, because it is very confusing.

The problem in this case is that the result hasn't been "taken back" -- in fact the article states people should continue to consume omega-3s.

I think a big problem is that the media often misrepresents scientific claims. There was a really good piece in Newsweek recently about how science gets reported in the news and how people get confused as a result.

The article notes that the study that found no significant effects was conducted on men with angina. So, if you are not a man with angina, the results may not apply to you. One of the things I try to teach my students is to look at who the sample is.

Scientific findings evolve slowly, but news outlets want to sell stories, so they often frame issues in a more sensational way. This article at least made the point about the sample issue, but they buried it.

I think scientific literacy is important to all of us for this reason, but the hardest part is that the news outlets are not clear in their reporting, so of course people get confused.

Are omega-3s good for you? I don't know. I know a lot of literature suggests they are, but maybe not for everyone. The research will continue, and hopefully we will learn more specific information about who is helped and when and with which doses... but again, that takes time. I will bet they aren't a panacea, and that in moderation, they could be helpful for many of us... as is the case with many foods/substances.

I think we SHOULD all be skeptical of every new thing that comes out as "healthy" etc... but I also think we can educate ourselves about when it IS appropriate to pay attention, and what questions to ask to get that information. Asking about the sample is an important feature of the research... and if anyone is interested, I have other suggestions too.

I would think they would be, but then it's hard to say. Just like with the Vitamin E thing - I took it every day. Then heard that people who regularly take Vitamin E may actually be increasing their mortality rate.

I have no plans to stop taking my fish oil (I take it every day) until I hear more 'evidence' that it does nothing for the majority of people. That and I just bought 2 new bottles.

Also, I somehow missed the area of the article where they said the testing was done only on men with agina. However, the article is somewhat misleading, with quotes such as these; “Long chain and shorter chain omega 3 fats do not have a clear effect on total mortality, combined cardiovascular events, or cancer,” wrote lead author Lee Hooper from the University of East Anglia.

Yeah, me too.

We drink milk because we think it's supposed to be good for us. Then one day it isn't good for you anymore. Now it's good for you again. Same with eggs. Things like that. But I suppose the new 'information' comes from further research.

Who knows, in 6 months we may find out that spinach causes cancer.

I wonder what they consider to be significant?

I wasn't sure if this is what you were asking, but statistically significant refers to the probability that the finding is due to chance. A non-significant finding in this case probably means that there is more than a 5% chance that the result is due to chance (though that percentage might be different in medical research than the standard we use in psychology).

Statistical significance is related to variables like the size of the sample and the size of the effect.

Given the size of the sample they reported, I was surprised that a 13% difference was NOT significant. That didn't sound right. Large samples need very little difference for the effect to be deemed "significant" and 13% is nothing to sneeze at, but I guess that depends on how they're measuring it.

As for Linda's comment that the article is misleading, I would agree! I would also agree that you should just keep taking that omega-3 until more evidence emerges about other groups of people...

This is why I am so skeptical of so many of the health related claims I hear... so many have been filtered through so many sources that the claims often bear little resemblance to the actual research findings.

I was wondering the same thing, hon.

Thanks for posting that, it sheds a little better light on the situation.

you're welcome. I teach this stuff all the time, so it just kind of flows out!

I just wish the science reporters did a better job, because you NEED advanced training to understand it the way they report it, when in fact it's not all that complex. I guess even in this internet age, they don't take the space to really spell things out. Or worse, the reporters don't really understand it themselves...

I take Fish Oil pills around my period, it helps with my cramps. As far as I'm concerned it's better than taking 20 + ibuprofen a day!

It's like coffee, one day it's bad for you, the next it's good.. you pick your evils, and I choose coffee! ;)

-Aimee

READ NYTIMES' Jane e. Brody articles. Recently, two insanely large studies concerning low fat intake and calcium vs. likelihood of diseases came up with the conclusion the attempt to decrease fat and increase calcium may not give any benefits. Here's the truth: IN ALMOST EVERY STUDY INVOLVING HEALTHIER SUBJECTS AND NORMAL SUBJECTS, THE HEALTHIER GROUP IS ALWAYS THE GROUP THAT HAS LESS ASSOCIATED DISEASES. WHEN THEY SAY INSIGNIFICANT, they mean the change was only SLIGHT. In fact, some cases require a difference above 9% to be significant. Significant or insignificant, you don't just throw down your diet regimen and go grab a burger. Eat what MAKES YOUR BODY FEEL GOOD.

I teach statistics and research design in psychology and just wanted to clarify again that insignificant does not mean "only slight". It's a specific term that refers to the probability that any difference found is just due to chance. This does often translate to a small difference, but when the size of samples is small, that's not the case.

In fact, with really really large samples (like the ones discussed in this study), a very very small difference between groups (less than 1%) might be significant (not due to chance). That doesn't mean it's meaningful or important.

When samples are really small, a difference of over 10% may NOT be "significant" -- but that doesn't mean there isn't a difference, and if you had a bigger sample, you might find the effect to be significant.

All of this is also affected by the level of certainty the researchers wanted to have that they were finding a "real effect" in the population, which can vary and is rarely stated in a secondary source news outlet article.

Enough to make your head spin, isn't it!

wyellen, I wish you taught farther down state. You would be my favorite teacher. ;)