September 2, 2009

Fish Oils & Fatty Fish

Happy September! Khavanu is 1 year-old. Yay!

I don't ususally recieve many questions on here about nutritonal benefits of foods, but Seestah sent me a text asking about the benefits of fish oils so I had to re-dig through some nutritional biochemistry notes and this post is about what I found.

(Yes, I have infinetly stupid nicknames)

Seestah's text: Is fish oil good?

Response: Essentially - as part of an overall healthy diet, fatty fish contribute omega 3 oils -which is what is largely found in fish oil supplements. The ratios of Omega 3:6 matter the most. It is also the DHA and EPA that are almost exclusively found in fish oil (as a supplement) or fatty fish (as a food). Omega 3 and 6 are supposed to reduce the risk of blood clots because they reduce vasoconstriction and platelet (plaque) build up. Here's why:

As you eat more fatty fish, you end up getting more omega 3 fatty acids in your cell membranes. Having more omega 3's around causes some competition with omega 6 in the cell membrane, as both arise from Arachidonic acid or arachidonate. Your body can make some omega 3 and 6, but just not enough, as to why they are essential fatty acids. Bear with me. This is important because if you have any amount of inflammation in or near the cell wall, such as lots of fat floating around in your arteries and banging around the walls to create inflammation, cells at the injury site, and those upstream and downstream from the injury site produce prostaglandins and of course a number of other signals.

Prostaglandins essentially inhibit platelet aggregation or platelet build-up. In some ways, omega 3 and 6 mimic prostaglandin activity. Omega 3 is better because it has a greater sum effect in reducing the amount of fibrinogen and other clotting proteins and it is much weaker platelet aggregator. Omega 6 (the kinds found mostly in plant oils, usualy ALA) has a weaker sum effect. What this means is that if you have a lot of omega 3 in the cell wall where you have inflammation on the arterial wall, then you will be less likely to have a clot or plaques form at the damaged site. Too much omega 3 supplementation can actually reduce blood clotting or cause poor blood clotting.

I was perhaps deliberate in not answering her exact question, but I write in terms of our food supply and general state of nutrition in this country. I prefer whole foods consumed in an overall healthful diet. Often, nutritional supplements contain too much of a nutrient, or require large doses as specified on the label. In these cases I will always answer that it's best to decide to take these with the approval of a physician and dietitian. In these cases, they are able to assess prior medical history, diet, current medications that you are already on, and any allergies that you may have.

For the latest and greatest here are some links:

http://www.cspinet.org/new/200710011.html

http://www.cspinet.org/new/pdf/omegas.pdf

http://eatright.org/ada/files/Martek_Fact_Sheet.pdf


http://www.americanheart.org/presenter.jhtml?identifier=4632

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