If you've ever wondered how fish oil got to be a health food, it all goes back to studies of Greenland Eskimos. Those eating a traditional diet have a very low rate of heart disease, but they consume an exceptional amount of fat. Perhaps, health experts speculated, the type of fat they ate made the difference.
Scientists later found that fats called omega-3 fatty acids were abundant in fish and appeared to reduce the risk of heart disease. Eating oily fish like mackerel and salmon now appears to offer other health benefits. Some studies indicate that fish oil improves learning disorders, like dyslexia, and can help treat such psychiatric illnesses as schizophrenia and manic depression, which is also known as bipolar disorder. It might even treat alcoholism and prevent a serious form of age-related vision loss.
|
Omega-3 Fats in Fish |
|
Food | Amount* |
| Mackerel | 2.5 |
| Sardines | 2.5 |
| Salmon | 1.8 |
| Herring | 1.6 |
| Crab | 1.0 |
| Canned tuna | 0.4 |
*Amounts in grams per 100 grams of fish (just under four ounces)
Source: University of Sheffield, England |
The London Sunday Times describes how one Irish physician now urges patients to use store-bought fish oil capsules for depression as well as for smoking and alcohol addiction. Anecdotal reports can't prove that the supplement works, but early clinical studies support the idea.
One British study of 40 children with dyslexia found that kids taking fish oil capsules behaved better in school and could concentrate more, the Electronic Telegraph reports. Schizophrenia.com reprints a wire service story describing a small but promising study of fish oil for the treatment of schizophrenia.
The most compelling evidence of fish oil's benefit so far comes from a large Australian study. Archives of Ophthalmology reports that the amount of fresh or frozen fish consumed seems to predict a person's chance of developing retinal degeneration with age, a condition known as age-related maculopathy, which is the leading cause of irreversible blindness in the United States.
There's also some bad news about fish oil. Fishes with the highest levels of omega-3 fats also tend to concentrate pollutants like mercury and PCBs (polychlorinated biphenals), so eating a traditional Eskimo diet might be unhealthful in other regards. A previous HealthDay story describes warnings from the U.S. Food and Drug Administration that pregnant women should avoid some fish because of high mercury content. For most people, however, eating fish once a week is safe.
