Proper balance needed in the omega families
The human body is a master of synthesis, but not when it comes to the two polyunsaturated fats in flaxseed: alpha-linolenic acid (ALA) from the omega-3 family and linoleic acid (LA), from the omega-6 fatty acid family (the numbers refer to their molecular structure).
Omega-3s and omega-6s both serve critical functions. But it's important to understand how they interact.
"Too much omega-6 it can be immune-depressive and cause increased inflammation," says Kelly Morrow, a registered dietitian and nutrition-clinic coordinator at Bastyr University. She says the trick is to achieve the right balance.
The typical Western diet, high in fat, meat and cheese, is overrun with omega-6s.
More omega-3s, fewer omega-6s are where it's at, says Morrow. What's unique about flaxseed is its beneficial ratio, almost 3-1 omega-3s to omega-6s. It's a ratio found in no other plant source.
Flaxseed is lauded all around, but a concern remains.
The omega-3s in flaxseed, the ALA, while still essential, serves primarily as the parent compound of the omega-3s that do the work everyone's talking about.
Once ingested, some ALA is converted by enzymes into EPA (eicosapentaenoic acid), some is converted into hormone-like chemicals called prostaglandins that promote cardiovascular health, and some is converted into DHA (docosahexaenoic acid), which helps regulate messaging between nerve cells.
But researchers question how much actually gets converted. "The problem is that the conversion is relatively slow," says Marian Neuhouser, a registered nurse and staff scientist for Fred Hutchinson Cancer Research Center. "It can happen, and it does happen, but it's a relatively inefficient process."
The estimated percentage depends upon whom you talk to, but most doctors and dietitians estimate the conversion between 5 and 15 percent. DHA conversion may be too insignificant, says Brian Higginson, a registered dietitian for Swedish Medical Center's Cardiovascular Wellness Program.
That's why dietitians prefer marine sources, because DHA and EPA are already converted in fish. Vegetarians who are concerned about getting enough DHA can skip the fish and go for DHA-rich algae, available in supplements from most health-food stores.
Ultimately the medical community says that variety is the spice of life. Eat your fish, but don't forget about the flax, because a balanced diet will ensure that your body is getting everything it needs.
Use flax oil to increase your omega-3s, add flaxseed for a good dose of protein and fiber, and ask your doctor about what flaxseed's cancer-fighting lignans can do for you.
— Kathy Mahdoubi
Copyright © 2006 The Seattle Times Company