Friday, March 30, 2012

Omega-3s for vegetarians

Next time you’re in the supermarket, take a look at some of the products fortified with omega-3 fatty acids: waffles, peanut butter, eggs, milk and yogurt, bread, orange juice and fake butter spreads.
 
Are sources of omega-3s for vegetarians as potent as cold-water, oily fish such as salmon and sardines?
 
Fish and fish oil are generally regarded as the best sources of these fatty acids, which we need to get from food, so what’s a fish-shunning herbivore to do? Especially when research has concluded that a diet rich in omega-3s:
 
 
study in the Yale Journal of Biology and Medicine analyzed research on fish oil dating back to 1970 and concluded that omega-3s reduce blood cholesterol and triglycerides as well.
 
(The same study also revealed that very high doses may prolong bleeding. Another study, from the University of Connecticut, stated that high doses cause blood vessels to rupture, possibly inducing stroke, so don’t start popping a fistful of fish oil pills.)
 
Strict vegetarians can cut out the middle man, er, fish
Fish aren’t born naturally oozing omega-3s out of their gills. It’s their diet of algae, krill, plankton and other microscopic primordial matter that flush the fish full of fatty acids. In essence, we get omega-3s from the fish because fish eat algae.
 
Strict vegetarians can now take supplements derived from algae that are free of fish oil. It’s best to get an algae supplement that contains both DHA and EPA, which are two of the three omega-3 fatty acids and regarded as the most beneficial fatty acids for health.
 
Fish oils are loaded with DHA and, to a lesser extent, EPA, both of which are found in the human brain and retina. One would assume that since fish get their fatty acid profile from algae, that algae supplements would be just as efficient as consuming a salmon filet.
 
Are DHA/EPA supplements as effective as whole fish?
We don’t know for sure, says, Edward Dennis, a professor at the University of California San Diego and editor-in-chief of the Journal of Lipid Research.
 
“Until researchers run a controlled study, it cannot be concluded that omega-3 supplements are as effective as omega-3-rich fish,” says Dennis, who is part of a "lipidomics" team of researchers, mapping out all the fatty acid molecules in the human body, much like "genomics" researchers a decade ago sequenced and mapped the protein-rich DNA sequences.
 
How many milligrams of omega-3 should I have each day?
Dennis also thinks there’s not enough scientific data for recommended dosages, although many health articles will suggest going for about one gram per day.
 
“Most physicians who give recommendations — either for vegetarians and omnivores — don’t have a basis for the dosage,” he says.
 
Should vegetarians consume more omega-3’s than non-vegetarians?
Not necessarily so, says a fatty acids researcher, who, coincidentally, is allergic to fish.
 
Dr. David Bernlohr of the University of Minnesota says he can’t eat fish because of an allergy, but he can stomach fish oil supplements.
 
“Certain fish have the highest fraction of omega-3s but you can clearly reach an equivalent amount by eating plant-based sources and taking supplements,” he says. “Even strict vegetarians can reap the benefits of the anti-inflammatory and immune-boosting properties that omega-3s offer.”
 
What about walnuts and flax seeds or oil? Aren’t they super rich in omega-3s?
Natural vegetarian sources like walnuts and flax seed and flax oil contain more ALA, the third type of omega-3.
 
Thus the dietary paradox for the strict vegetarian: On one hand, ALAs are the most bioavailable of the omega-3s (the body can metabolize it easier), but ALAs don’t do such a good job converting into DHA and EPA, which are widely regarded as being more potent. Some statistics claim only 5 percent of ALA gets turned into DHA and EPA.
 
According to the American Journal of Clinical Nutrition, walnuts have the highest omega-3 content of any common nut, with 30 percent of it comprised of ALAs. (Only an Indonesian nut — the candlenut — has more.)
 
Flaxseed oil contains the richest amount of ALAs, though it does have a high omega-6 to omega-3 ratio, a common trait of the typical Western diet and a factor that theUniversity of Maryland cites as a possible cause for inflammation.
 
Canola oil (at right) has the best omega-6 to omega-3 ratio: 2 to 1, making it a perfect salad dressing for vegetarians or for light sautéing cooking oil.
 
A final word on omega-3s for vegetarians:
The Vegetarian Nutrition Dietetics Practice Group of the Academy of Nutrition and Dietetics says, “Although vegetarians tend to have lower blood levels of long chain omega-3 fatty acids, it is sufficient to meet the needs of most people … however, certain factors can … adversely [affect] this important conversion process [including] high intakes of saturated fat, trans fatty acids, cholesterol and alcohol, an inadequate intake of energy or protein, or a deficiency of certain nutrients, such as zinc or copper.”
 

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