CNN says fish oil does not prevent strokes

If you're like the many folks who watched CNN a few weeks ago, then you no doubtedly heard cardiologist Dr. Nieca Goldberg tell CNN House Call host Dr. Sanjay Gupta, fish oil does not prevent strokes. However, Dr. Goldberg went on to say, eating fish has been shown to lower the risk of stroke.

So now, if you're like many people, you're left wondering if you should continue to follow government recommendations promoting fish oil as a heart-healthy product or if you should toss out all your pills.

Well, first it's important to know the study Dr. Goldberg was referring to in the interview. Recently, the findings of a new study by Dr. Craig Anderson, from Australia, has found that when people who have already had a stroke take fish oil pills, their risk of another stroke does not decline. Participants of the study were divided into two groups and for 12 weeks either recieved "a more concentrated, fresher omega 3" than can be bought in a store. After those 12 weeks, total cholesterol, LDL (often referred to as "bad" cholesterol). HDL ("good" cholesterol) and the tendency of blood to clot did not appear to have been changed in either group.

Due to these findings, the studying concluded that fish oil pills have no affect on a person's risk of stroke.

However, the study did admit to limitations, or possible shortcomings of the research, such as the small sample size (which can affect the meaning and application of results) and only physiological changes were measured (such as HDL cholesterol) instead of an outcome such as if another stroke is really prevented by the fish oil pills.

Therefore, the researchers concluded that it may be a better idea to consume fresh fish, as opposed to fish oil pills.

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So, the research suggests fish oil pills may not help prevent stroke, as they have not been proven to lower labs that are typically indicative of stroke risk.

That is something most people, including myself can wrap my head around: research doesn't support fish oil pills and stroke prevention. But does that mean fish oil pills aren't beneficial?

Instead of diggin up a variety of other research articles (and be so kind as to link directly to the article instead of a consumer-friendly version), I'll focus on fish oil in general.

Dietary recommendations include eating fish at least twice a week because fish oil contain two types of omega-3 fatty acids called DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). Numerous studies, though obviously not Dr. Anderson's, have shown DHA and EPA from both fish and fish oil supplements, lowers cholesterol, the risk of heart attack, slows the hardening of arteries and slighly lowers blood pressure.

Again, these studies most likely had their limitations as well. However, the key here is that more than one study had a similar finding. This point is important anytime you are trying to understand results from a study.

When trying to evualuate how reliable a study is, in otherwords, how reputable a study is, look at these things:

1. Sample size. The large the sample size, the more stastically significant the results are; they are more applicable to more people.

2. Length of the study. Depending on what is being measured, a longer study may have been needed. For example, weight loss takes a while and it would be unrealistic to measure the effectiveness of a new exercise program after only one week.

3. Study design. Was there a control group? How were groups assigned? The best bet is to look for research that randomly assigned participants to different groups and used a control group (some people either did the same thing they always did or took a placebo).

4. Who conducted the research. If a company sponsored their own research, you might be a little suspious of the results. This is not to say every company will manipluate results, but just keep this in mind. For example, the Gatorade Sports Science Institute is a wealth of sports nutrition and physical activity information. Even though they're vested in the effectiveness of Gatorade, they are objective with their research (not every study finds Gatorade is best).

Use your noggin. If it seems too good to be true, it probably is.

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Lastly, the health benefits of Omega-3s don't end at preventing heart disease.

Omega-3s are believed to be important in brain and eye development in infants; decreasing inflammation; helping prevent certain cancers; and preventing heart disease.

Cold-water fish such as salmon, herring, mackeral and even shrimp contain the Omega-3s DHA and EPA. Besides fish, you can find plant-based Omega-3s in foods such as walnuts, milled flaxseed, flaxseed oil, canola oil and olive oil.

Really, the key is eating real food. No one is completely, 100% sure how each nutrient works. In fact as more is learned about nutrients, researchers are finding that most nutrients work in combination with each other in the body. A great example of that is calcium. Yes calcium is important for strong bones. But without vitamin D, calcium wouldn't get much done.

Don't rely on supplements to take the place of eating real food. Food first.

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Resources and links for more information (note I won't be updating them once this blog entry is posted):

CNN transcript of House Call, Feb 23, 2008

Dr. Craig Anderson's research (MD Web)

Omega-3 Fatty Acids