May 10, 2002
Melinda T. Willis
Fish oil is good for you, but is it a miracle cure for excess weight and disease?
While Barry Sears, creator of the popular low-carbohydrate "Zone" diet, certainly thinks so, other experts are dubious.
Sears claims in his new book, The Omega Rx Zone , that supplementing the Zone diet with omega-3 fatty acids commonly found in fish is the key to wellness. He adds that his book can reveal the status of your immune system and that fish oil can be used to correct any imbalances, fight disease and shed excess pounds.
In fact, numerous scientific studies have shown that fish oils can be beneficial to varying degrees for the treatment or prevention of a variety of diseases, ranging from depression to multiple sclerosis.
The strongest evidence seems to be for heart disease. Several recent studies have found some benefit in the prevention of sudden death due to heart attacks related to fatty fish consumption.
But some experts say that the omega-3 fatty acids, while promising, are not quite as miraculous as Sears suggests.
"You can talk something up out of proportion and in this case I think we need to keep some perspective on things," says Dr. Donald Hensrud, associate professor of preventive medicine and nutrition at the Mayo Clinic in Rochester, Minn.
No Diet Miracles
Experts agree that Americans should make more room in their diets for omega-3 fats, because of their demonstrated benefits -- especially for people with heart disease or those who are at high risk.
"There's plenty of research to show that Americans do not eat enough omega-3 fats and #151 that is clear," says Elizabeth Ward, a registered dietitian and author from Massachusetts. "Where I become hesitant is with the idea that omega-3 or fish oil is the magic bullet -- is the answer to all of our weight-control, health and diet problems. There is no magic bullet. There is no single answer."
And people should be wary of medical claims that focus on those single answers or simple solutions.
"Omega-3 fatty acids are one component to a healthy diet. There are many other components that are beneficial," says Hensrud. "People need perspective."
One of Sears' key claims, for example, is that fish oils can be used to control hormones, an important factor in attaining wellness.
"Wellness has really been defined as hormonal balance," says Sears. "The better you can balance your hormones, the better well we are."
Sears maintains that through individual interpretation of blood tests -- finding the ratio of fats called triglycerides to levels of "good" or HDL cholesterol, for example -- one can determine how much fish oil they should be taking to obtain hormonal balance.
"Omega-3 fats do lower triglycerides, but in some cases you do need very large doses -- up to 20 capsules a day," says Hensrud, who has recommended the use of fish-oil supplements in his own practice. "It's difficult to do at that level. Compliance is not very good at that dose."
Lower triglycerides are indeed a goal of healthy living, but experts also warn that it isn't possible to control hormone levels precisely through diet.
"If it was that easy, we'd all be doing it," says Ward. "All these solutions -- they just sound too good to be true."
Fish as a Drug
And some fear that suggesting people try to interpret their blood tests and suggesting a simplistic perception of treatment may be dangerous.
"I am really nervous about the implications for self-medication with all these claims," says Ward. "People don't pay enough attention and we don't really know enough about the interactions between dietary supplements such as omega-3 fats and any medication that you may be taking on a daily basis."
High doses of fish oil may cause gastrointestinal disturbances and there has been some concern that fish oil may affect bleeding, especially in patients taking other blood-thinning medications.
While eating fatty fish at least twice a week is currently recommended by the American Heart Association, experts warn that there are differences between moderate consumption and using high doses of omega-3 fats pharmacologically.
"There's much less variability in eating fish than with taking fish
oil -- there's a limit to how much fish you can eat," says Hensrud. "But
when you are taking fish-oil supplements, that's using it as a drug and
not as a food. I think when you're using something like that, it's best
to discuss it with a physician."
Copyright 2002 ABCNEWS.com