Types of Omega 3

[Maryanne]

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A Quick Course In The Benefits Of Omega-3 Fatty Acids

Buffalo News

December 4, 2005

Health claims on food are proliferating, and one that's particularly popular is using omega-3 fatty acids to improve cardiovascular health, in addition to other health benefits. Here's the lowdown on this healthy fat.

Are omega-3s necessary in our diets?

"You can probably live without eating any omega-3s, but you may not function as well," says Debra Palmer Keenan, Ph.D., a nutrition professor at Rutgers University in New Jersey.

Additionally, omega-3s are found in breast milk and have been shown to be important in brain and eye development, explains Jay Whelan, Ph.D., a professor of nutrition and omega-3 researcher at the University of Tennessee.

What are omega-3s, and is there a difference between the omega- 3s in fish and those in walnuts?

Omega-3 fatty acids are a type of polyunsaturated fat. There are a few types of omega-3s: EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid) and ALA (alpha linolenic acid).

"They are not the same thing -- we have to stop talking about omega-3s and talk about DHA and EPA and ALA as separate fatty acids," says Keenan. EPA and DHA are the most valuable to health and wellness. They come from fish oils. Both play an important role in normal function of the heart, brain, eyes, nervous system, kidney and liver. These "essential" fats have also been proved to reduce the risk of cardiovascular disease and inflammation.

"If you get ALA from walnuts, flaxseed or canola oil, it can be beneficial because it gets converted to DHA and EPA, but that's only if ALA is already lacking in your diet, which it probably isn't," says Whelan. Eating more ALA just for it to be converted to EPA and DHA is not recommended -- "The amounts converted are very small, and in the long run, ALA starts to replace the needed DHA in the tissues -- not a good thing," adds Whelan.

Why are omega-3s getting so much attention?

One of the key health benefits is that they significantly reduce the risk for sudden death caused by cardiac arrhythmias and decrease all-cause mortality in patients with known coronary heart disease.

In fact, last year the FDA allowed the following claim to be placed on certain foods: "Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease. One serving of (name of food) provides (x) grams of EPA and DHA omega-3 fatty acids." The label must state the quantity of omega-3 fatty acids the product contains; however the FDA didn't require the food to contain a minimum amount of omega-3s to carry the claim.

Other health benefits

"This could be one of those nutrients that becomes a 'magic bullet,' but we don't say things are conclusive until there have been many more studies -- yes, the evidence looks strong, but we are not quite there yet," says Keenan.

Omega-3s (specifically DHA and EPA) are being examined for other health benefits, including: treating rheumatoid arthritis, ulcerative colitis and Crohn's (because of their anti-inflammatory properties); treating depression and other psychological disorders (because they may boost levels of serotonin and dopamine, decreasing depression and violent behavior); reducing the risk of diabetes, insulin resistance in people with diabetes, psoriasis and other skin conditions; helping osteoporosis (because they may enhance bone density); and fighting cancer (they may inhibit cancer cells in the breast, prostate and colon). In infants, omega-3s may improve cognition and visual acuity.

Sources of omega-3s

Soybeans and soybean oil, canola oil, walnuts and flaxseeds and their oils are rich sources of ALA.

Fatty fish, such as salmon and tuna, and fish oil are rich sources of EPA and DHA. For a complete list of omega-3s and where to find them, check out: www.ncbi.nlm.nih.gov/books/ bv.fcgi?rid=hstat1a.table.38454.

The FDA advises not to eat shark, swordfish, king mackerel or tilefish because of mercury. Another commonly eaten fish -- albacore ("white") tuna -- has more mercury than canned light tuna. Review mercury levels at www.cfsan.fda.gov/~frf/sea-mehg.html.

Can you get omega-3s without eating fish? There are new products on the market made with encapsulated fish oil (e.g., Arnold Smart & Healthy Omega-3 bread) -- so it doesn't smell or taste like fish. If you're not getting omega-3s from any other fish sources, these are a good option, but we don't know enough to say that the fish doesn't have other properties working in conjunction with the omega-3s to create these purported health benefits.

What about omega-3 supplements? Some research has shown positive outcomes for omega-3 fish supplements over a placebo. Plus, "So far, fish-oil supplements have lacked contaminants such as mercury and PCBs," says Tod Cooperman, M.D., ConsumerLab.com's president.

Find information on fish-oil supplements, see: www.consumerlab.com/results/omega3.asp and for omega-3 seed oils visit www.consumerlab.com/results/flaxseed.asp.

How much do I need to reap the benefits?

The American Heart Association's (AHA) recommendations:

* Without documented Coronary Heart Disease (CHD), eat at least two servings of fatty fish per week, along with other foods rich in omega-3s.

* With CHD, eat at least one daily meal that includes a fatty fish or take a daily fish-oil supplement (0.9 gram per day of EPA).

The AHA also recommends, "People who have elevated triglycerides may need 2 to 4 grams of EPA and DHA per day provided as a supplement." They recommend the supplements because "even the 1- gram-per-day dose recommended for patients with existing CVD may be more than can readily be achieved through diet alone." They also suggest consulting your physician before taking this or any other supplement.

(C) 2005 Buffalo News. via ProQuest Information and Learning Company; All Rights Reserved

Do you have a contact point for the above. There are some issues I would like to try and clarify.

Most of it I agree with but no mention is made of omega six. and the key factor is the omega three six balance, in respect of the functioning of the eicosanoid pathway. -see Articles of interest - The importance of omega three and six to breast cancer. It is the excess omega six that is most likely the cause of the problems.

I have not seen any reports on what the body does with excess omega three in comparative preferential fat storage terms, but is does promote the the burning of adipose tissue. From what I have read the body moves fats about and converts them up and down as required. Linoleic acid LA, and alpha-linolenic acid ALA cannot be made in the body, but all others in general terms can. LA and ALA are used in totally different fat pathways in the body. Fats that can be synthesised include as stated DHA and EPA which would make sense in survival evolutiionary terms as some culture have no access to fish or do not eat it. I have a question here why should ALA when stored not replace LA AND if LA as reported is a cancer percussor but ALA is not, and the body is able to draw down and use and convert fats as needed would ALA storage be preferential to LA storage. ( my presumtion is it would because of the nature of the eicosanoid pathway)

I Know I keep bleating this but once anybody has done a bit of background reading on teh eicosanoid pathway they will quickly understand the relevance. I get very frustrated by the apparent lack of consideration of the omega six factor in many considerations of the subject.

This as usual is complex. But it is reported that once the omega three six balance gets past a ceratin point the preferential usage of omega threes in the pathway is disturbed, in favour of omega six which means fuelling the omega six pathway which as previously posted ups HER 2, CDL40, Endothelin B, and a whole host of others all implicated in cancer pathways (and cox 2s) .

Many reports I have read indicate a general falling rate of omega three intake and huge increases in omega six.

Readers may wish to bear in mind that Soy and walnut are high in omega sixes (51 and 60 % respectively in one report I have read).

I tried to have this discussion with the Nutrionalists at complementary based cancer centre in Bristol in the but despite my best efforts they never came back to me.


RB