Omega-3 Summary

written by bryan on September 12th, 2007 @ 10:28 AM

Omega-3 is the latest health craze. Unlike many previous health crazes, this appears to be well founded scientifically: many studies have shown consistent, significant and widespread health benefits.

Omega-3 is an Essential Fatty Acid. There are 3 types of Omega-3 EFA’s. There are 4 types of Omega-6 EFA’s. Omega-9 is not an EFA.

The body can convert between the three different types of Omega-3 EFA’s. However, this uses the same mechanism that the body uses to convert between the four different types of Omega-6 EFA’s.

Therefore, for optimum health, you may follow either of the following two strategies.

Vegetarian Strategy

  • Ingest a sufficient amount of any type of Omega-3
  • Ingest a sufficient amount of any type of Omega-6
  • Ensure that the ratio of Omega-6 to Omega-3 stays in the range of 1:1 to 4:1

What is a sufficient amount? A common recommendation is that 33% of your calories come from fat, and that at least 10% of these calories come from EFA’s. At a 3:1 ratio and a 3000 calorie/day diet and 9 calories/gram, this works out to 8.3g of omega-6 and 2.8g of omega-3.

Here are the omega-3 and omega-6 contents of common oils:

http://www.mcgacanola.org/images/fatchart_000.jpg

As you can see, canola oil is the only oil that has a healthy ratio of omega-3 to omega-6. For olive oil, a healthy ratio may be maintained by adding 1 gram of flaxseed oil to every 8-40 grams of olive oil used. (If you use flaxseed gelcaps, that might easily be 10 gelcaps a day!)

These omega-3 values are for uncooked oils. Using oil for frying destroys most of the omega-3 in the oil.

WARNING: a diet high in unsaturated fat and low in saturated fats has been linked with heart disease. Adding a small amount of tropical or animal fats is also a good idea.

Omnivore Strategy

For most people, it is probably easier to ensure that they ingest a sufficient amount of all 3 types of omega-3 rather than trying to maintain an optimum omega-6/omega-3 balance.

Omega-3 from plant sources is primarily ALA. Animals (including humans) convert this into the other two forms: EPA & DHA. The National Institute of Health recommended 650mg of DHA+EPA. (At least 200mg of each for a total of 650mg). This corresponds to 4-5 servings of fatty fish (tuna, salmon, mackeral, anchovies, herring, saury) a week, or 5 omega-3 eggs per day.

The health benefits of omega-3 exceed the health risks of mercury exposure; however carefully read these Health Canada recommendations. To summarize:

  • maximum 1 serving per week of shark, swordfish, fresh tuna or frozen tuna
  • maximum 4 servings per week of canned tuna
  • prefer light tuna over white (albacore) tuna.

Cooking (especially frying) destabilizes Omega-3, so do not fry or overcook your fish.

If you don’t like fish, a typical omega-3 supplement based on fish oil likely contains the recommended daily dose. Look for molecularly distilled oil to eliminate your mercury exposure.

Whole Flaxseed versus Oil

You may read that whole flaxseed is preferable to its oil. This is due to the presence of lignan, a plant estrogen. Lignan is a potent anti-oxidant, so may reduce the risk of cancer. However, hormones are not benign; too much is quite possibly a bad thing. Source: UCBerkely.

Sources:

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