Whether Farmed or Wild, Salmon Is Rich in Omega-3
It’s time to answer some of the mail that has piled up on our desks and in our electronic mailboxes. Here are some reader questions we hope will interest you as well.
Question: My cardiologist says that farmed Atlantic salmon is not a source of omega-3, that I must use canned salmon or wild salmon. Not only are those types of salmon expensive, they’re also hard to find.
Answer: It is true that in oceans and lakes, fish get omega-3 fatty acids from eating algae. But farmed fish also eat algae and, in general, have as much omega-3 as do wild fish. They tend to be fatter (three to five times as much fat); thus the proportion of omega-3 to other fat may be lower.
For example, in wild fish, omega-3 fatty acids account for about one-third of the total fat in the fish, compared with about one-fifth of the fat in farmed fish. But the amount of omega-3 you’d get in a serving would be about the same because the farmed fish has more fat to begin with.
Evidently, fish just won’t grow and thrive unless they have omega-3 in their diets. So the farmed fish have to be fed algae or fish oil to make sure that they get it just as they would in the wild. Since fish vary tremendously in the amount of fat (and omega-3) they contain, it’s always a good idea to eat a variety of fish, especially the fatty ones.
Q: Do you have information about a recent Swedish study on acrylamides in fried foods? This seems to be a significant health issue.
A: It’s probably just as well that you haven’t been able to find out much about this study. We actually thought it got more publicity than it deserved. The short answer to your question is that this is not something you should worry about. The study, which hasn’t yet been published, did not show anything that should cause people to change their eating habits.
For those who missed this particular round of scary headlines, researchers in Sweden showed that fried or baked starchy foods (such as potatoes, bread, cereal and crackers) were found to contain high levels of an animal carcinogen known as acrylamide.
We have long known that high-heat cooking can produce a number of chemical compounds, some of which are carcinogenic. But, of course, deep-fried foods should be eaten only in moderation--you’d have to eat huge quantities before acrylamide became the biggest problem you’d have with these foods.
We still maintain that eating such foods as bread, pasta, breakfast cereal and other complex carbohydrates is a good idea; this study should not dissuade you from including them in your diet.
Q: Is food cooked in a microwave oven less healthy than food cooked in a conventional oven?
A: In the early days of microwave ovens, some people worried that the seals around the doors were not sufficient to keep the microwaves themselves from leaking out, and that someone standing directly in front of the oven watching the miracle of cooking might be exposed. Although that was never a very big problem, the new generations of microwaves have better seals.
In terms of cooking process, there is no danger from the microwaves themselves. In a microwave, vegetables can be cooked in a small amount of water in a short amount of time. This is good because it preserves the nutrients in the same way steaming does.
Some caution is appropriate, however. If you are cooking raw meat, you must check carefully to make sure that it is fully cooked because microwaves do not always cook evenly.
If you are using the microwave for reheating cooked food, the same caution is necessary.
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Dr. Sheldon Margen is a professor of public health at UC Berkeley; Dale A. Ogar is managing editor of the UC Berkeley Wellness Letter. Send questions to Dale Ogar, School of Public Health, UC Berkeley, Berkeley, CA 94720-7360, or e-mail to daogar@well nessletter.com. Eating Smart appears occasionally in Health.
